Fokker Technologies

Fokker Technologies is a Dutch aerospace company owned by British aerospace supplier GKN. The company has production companies which design, develop and produce structures, landing gear and electrical systems for the aerospace and defense industry. Additional to the production capabilities, it also supplies integrated maintenance services to aircraft owners and operators.
Operations.
Fokker Technologies designs, develops and produces advanced structures and electrical systems for the aerospace and defense industry and supplies integrated maintenance services and products to aircraft owners and operators.
The company consists of four business units:
History.
After the bankruptcy of the former aircraft manufacturer Fokker in 1996, Stork B.V. acquired the Fokker companies specialized in the building of aircraft components and aircraft maintenance services which were named as Stork Aerospace. The group has had many names until in 2010, the Fokker name was reintroduced.
In July 2015, the British aerospace supplier GKN announced that it intention to acquire Fokker Technologies from Arle Capital, at the value of €706 million. Fokker was acquired in the same year by GKN.


Skateboard (automotive platform)

A skateboard is a type of configuration for automotive chassis, used for automotive platforms of battery electric vehicles. The skateboard chassis includes a base structure or a platform, which houses the batteries, electric motors and other electronic components fundamental to an electric vehicle.
A skateboard chassis cuts down the cost and complexity of manufacturing and production of electric vehicles, as it is a self-contained platform, with all the necessary driving and electronic components integrated into it, and which can be mounted with a variety of bodies after scaling them into various sizes. The skateboard allows an automaker to design and manufacture vehicles in several vehicle categories and body segments without engineering each one independently.


Prusa Mini

The Prusa Mini, sometimes stylized as the Original Prusa MINI, is an open-source fused deposition modeling 3D printer that is manufactured by the Czech company Prusa Research. The printer is the lowest cost machine produced by Prusa Research and is designed as a first printer or as part of a 'print farm'.
Specifications.
Mini.
The Prusa Mini was officially launched in October 2019. The printer is available either assembled or as a kit. The build volume is 180 x 180 x 180 mm, and the print is performed on a spring steel sheet which meant to be easy to remove. Minimum layer resolution is 50 micrometers, and the maximum print speed is 200 millimeters per second. The printer has an LCD color display (non-touch), is able to print via USB drives. It has a custom 32-bit mainboard and a built-in online firmware updater. The printer has sensorless homing using Trinamic 2209 drivers and has a custom hot end which supports E3D nozzles.
It has several safety features including three thermistors to detect thermal runaway.
The printer is the first open source hardware product to require a user wishing to use unsigned firmware to physically break off a piece of the PCB, voiding the printer's warranty, before it can be flashed onto the board. This made sure Prusa wasn't liable for damage caused by printers instructed to behave in an unendorsed manner by custom firmware (such as disabling thermal runaway protections or other safety features).
Mini+.
In November 2020, the Prusa Mini was replaced by the Mini+, which had a few small updates meant to ease assembly and maintenance. One of the changes was a new mesh bed levelling sensor called "SuperPINDA" which replaced the previous "MINDA" sensor, and it is claimed by the manufacturer that this should result in a more consistent calibration of the first print layer in particular. The Mini+ the filament sensor, is an optional extra.


List of British Rail power classifications

The British Transport Commission, later British Railways, used engine power output to categorise its requirements for the new main line diesel locomotive fleet following the 1955 modernisation plan. The locomotives built and put into service are listed below classified with the TOPS class numbers that were introduced in the early 1970s.
Type 1.
Locomotives classed as Type 1 were of 1,000 bhp or below.
Type 2.
Locomotives classed as Type 2 produced between 1,001 bhp and 1,499 bhp.
Type 3.
Locomotives classed as Type 3 produced between 1,500 bhp and 1,999 bhp.
Type 4.
Locomotives classed as Type 4 produced between 2,000 bhp and 2,999 bhp.
Type 5.
Locomotives classed as Type 5 produced 3,000 bhp or more.


Feature recognition

The term "feature" implies different meanings in different engineering disciplines. This has resulted in many ambiguous definitions for feature. A feature, in computer-aided design (CAD), usually refers to a region of a part with some interesting geometric or topological properties. These are more precisely called form features. Form features contain both shape information and parametric information of a region of interest. They are now ubiquitous in most current CAD software, where they are used as the primary means of creating 3D geometric models. Examples of form features are extruded boss, loft, etc. Form feature is not the only type of feature that is discussed in CAD literature. Sometimes a part's functional or manufacturing features of the subject of attention. Although it is quite possible to see form features and manufacturing features are called by the same name, they are not exactly the same concepts. For example, one may either use the name "pocket" to refer to a swept cut on the boundary of a part model, or to refer to a trace left on the part boundary by a specific machining operation. The former is exclusively concerned with a geometric shape whereas the latter is concerned with both the geometric shape and a manufacturing operation, needing more parameters in its definition. As such, a manufacturing feature can be minimally defined as a form feature (if it has a form that can uniquely represent it), but not necessarily vice versa (forms can be interpreted differently in different manufacturing domains). Machining features are an important subset of manufacturing features. A machining feature can be regarded as the volume swept by a "cutting" tool, which is always a negative (subtracted) volume. Finally, there is also the concept of assembly feature, which encodes the assembly method between connected components.
Feature data in CAD can be specified either as a collection of surfaces or as volumes. Surface features can be used to describe manufacturing tolerances or locating surfaces in assembly design. Volumetric features on the other hand, can be used in tool path generation, etc. Manufacturing information (particularly in machining) is better portrayed by using volumetric features.
The first published work on features was for the original boundary representation modelling system, BUILD, and was performed by Lyc Kyprianou. Soon other work followed based on different solid representations. Overviews on the work on features can be found in Shah et al.; Subrahmanyam and Wozny; Salomons et al.
Technology.
Work on features (generally called feature technology) can be divided into two rough categories: Design-by-features and Feature recognition. In design-by-features, also known as feature-based design (FBD), feature structures are introduced directly into a model using particular operations or by sewing in shapes. On the other hand, the goal of feature recognition (FR) is to algorithmically extract higher level entities (e.g. manufacturing features) from lower level elements (e.g. surfaces, edges, etc.) of a CAD model.
Form feature generation model.
Completeness of feature set is very subjective, domain dependence eludes a formal definition. Feature generation model proposed by Nalluri and Gurumoorthy attempts to define the completeness of a feature set. They define domain independent form feature as a set of faces with distinct topological and geometric characteristics. They have modelled creation of a form feature as addition/subtraction of feature-solid (exact minimum volume required) to/from based-solid. They define feature "Type" based on the local topology of participating base-solid faces and "shape" based on shape of the feature-solid. Based on these definitions, they have enumerated and classified form features. For example, they have enumerated 94 sweep form feature types with possibility of each feature type having unlimited number of shapes. They provided proof those 94 types are complete for sweep feature-solid. They have modeled the feature extraction as a reverse process of their feature generation model. They have developed a feature recognition algorithm based on the concept of computing dynamic topological status of faces. They also defined a framework for mapping these domain independent features to a specific domain of interest.
Design by features.
By using features to build up shape models, the design process is made more efficient, because the shape of features can be pre-defined. Features in FBD can be directly associated to manufacturing information so that these informations can be retrieved in downstream applications. In this way, an overall CAD/CAM system can be fully automated, however, the idea of using manufacturing features to design a part has its own shortcomings: The features used to design the part do not necessarily represent the best way to manufacture it. It is, therefore, the designer's responsibility to evaluate all methods that can produce the part. Furthermore, manufacturing features are not the most natural way of designing a part.
Feature recognition.
The method proposed by Kyprianou was aimed to encode parts for group technology (GT). The purpose of GT is to systematically classify objects based on their manufacturing method. Kyprianou's work involved classifying faces into primary and secondary groups and then identifying features according to patterns of these primary or secondary faces. A primary face is one with multiple boundaries (also called "hole-loops") or mixed concave and convex boundaries. A concave boundary is a set of concave edges, where the solid angle over the edge is more than 180. Secondary faces are all other faces. Kyprianou's work was continued and extended by Jared et al. to cover a number of important special cases where features interacted.
Automatic Feature Recognition (AFR) is regarded as an ideal solution to automate design and manufacturing processes. Successful automation of CAD and CAM systems is a vital connection in building Computer Integrated Manufacturing (CIM) systems. This is the part of the FR research that has attracted much of the attention. Another important application of AFR is for manufacturability evaluation. The AFR system should be able to interpret the design differently based on alternative features and feed back the manufacturability and cost of those interpretations to the designer.
There is a big stockpile of different AFR techniques that has been proposed for CAD/CAM integration and process planning. Han et al. provides a critical and detailed analysis of some of the existing approaches. The most common methods according to Han et al. range from graph-based algorithms to hint-based and volumetric decomposition techniques. In the graph-based feature recognition, a graph showing the topology of the part (connection of faces) is created. The graph is often attributed, for example the edges are marked as concave or convex. This graph is then analyzed to extract subsets of nodes and arcs that match with any predefined template. This is done by a variety of techniques, including graph iso-morphism algorithms.
Graph based approaches have been criticized for several shortcomings. They fail to account for manufacturability of the recognized features due to their strong reliance on topological patterns rather than geometry. The intersection of features causes an explosion in the number of possible feature patterns that spoils any attempt to formulate feature patterns. To address these difficulties, Vandenbrande and Requicha. proposed to search for "minimal indispensable portion of a feature's boundary", called hints, rather than complete feature patterns. For example, presence of two opposing planar faces is a hint for potential existence of a slot feature. Hints are not necessarily restricted to the part geometry. They can be extracted form tolerances and design attributes as well. For example, "a thread attribute may be taken as a hole hint". This approach has been more successful in recognizing intersecting features. However, the efficiency of the approach has been argued, as there could be a huge number of traces that won't lead to valid features. Some authors have been in favor of using a hybrid of graph based and hint based FR to improve the efficiency of hint-based reasoning. In the hybrid approach, graph-based reasoning is used to find out those regions of the part that certainly lead to valid features when used by the hint based reasoner. Other existing FR approaches are volumetric decomposition, Artificial Neural Networks, and expert systems Babic et al. briefly introduces many of them.
However, building feature recognition systems that function effectively on real industrial products has been elusive. A real product with hundreds of faces and end edges brings almost all the above approaches to a halt due to computational complexity. Furthermore, the features studied in these approaches are usually over simplified. The bulk of the feature recognition literature normally deals with 2.5D features (those made by sweeping a 2D profile along a linear axis). Graph representations, hint definitions or volume decompositions are much more difficult to define for 3D and free form features. The work done by Sundararajan is focused on free form surfaces, but again it is limited in application. Oversimplification is also evident even in the course of 2.5D features. For example, feature recognition algorithms usually assume sharp concave edges in the feature geometry. However, such edges are barely used in real design of mechanical components due to manufacturing constrains. Some of these issues such as the presence of filleted edges and free form surfaces in the model have been studied by Rahmani and Arezoo.
Commercial feature recognition systems.
Few commercial feature recognition systems are also available. Though feature recognition technology can be applied for various applications, commercial software have effectively adopted feature recognition technology for recreating the feature tree from imported models so that even the imported models can be edited as if it were a native solid model. Major 3D CAD modelers have Feature Recognition to convert imported 3-D models into native feature based models. CAM software and design for manufacturing software are also built using this feature recognition technology. Few CAD/CAM software have used commercially available third-party feature recognition library, which recognizes various features from 3-D B-Rep models. Separate libraries are available for Design, Manufacturing and Sheet metal applications. Design feature recognition library can identify features such as holes of various types, split holes, hole-chains, fillets, chamfers, cut extrudes, boss extrudes, drafted extrudes, revolved cuts, revolved bosses, ribs, drafts, lofts and sweeps are identified. Manufacturing feature recognition library provides recognition of manufacturing features such as simple holes, tapered holes, counter-bore holes, counter-sunk holes, counter-drilled holes, hole-chains, hole patterns such as linear, rectangular and circular patterns, fillets, chamfers, blind pockets, through pockets, drafted pockets, filleted and chamfered pockets, simple slots, drafted slots, filleted and chamfered slots, islands in pockets and slots, machinable volumes, machinable slabs, multiple intersecting features, axi-symmetric features such as external turned profiles, internal turned profiles, turned grooves such as vee and dovetail grooves, and mill-turn features such as slots and pocket in turned profiles. Sheet metal feature recognition library extracts features from a sheet metal perspective. Various features identified through this library include walls, bends, holes, cutouts, flanged holes, flanged cutouts, notches, open hems, closed hems, teardrop hems, rolled hems (curls), jog flanges, edge flanges, contour flanges, stamps such as louver, lance, bridge, dimple, beads, embosses and ribs. Though such commercial systems can identify a variety of features listed above, further research can be driven to identify feature types that are not identified by such commercial systems. Manufacturing features such as 3-axis and 5-axis feature recognition are generally not available in such commercial systems.


Sigg

Sigg Switzerland AG is a Swiss manufacturing company with its headquarters in Frauenfeld. Sigg bottles are bottles designed and manufactured in Switzerland from aluminum and polypropylene or in China from stainless steel and glass. The company is famous because of the iconic shape its classic bottle and numerous designs which have led to its addition to the permanent design collection of the New York Museum of Modern Art.
History.
The company was founded in Biel in 1908 by Ferdinand Sigg und Xavier
Küng under the name Küng, Sigg & Cie. and produced kitchenware, bottles and
electrical appliances from aluminum. In 1916 the company moved to Frauenfeld and changed the name to
SIGG Aluminiumfabrik. Since 1998, the company has concentrated on the manufacture of bottles. According to market research, the company name is known by 70 percent of people in German-speaking countries.
Through the 1980s Sigg manufactured impact-extruded aluminum bottles for stove fuel storage and transport, popular with mountaineers, hikers and campers. The fuel bottles superficially resemble the water bottles, but lack the special linings of the latter. Now the company doesn't manufacture fuel bottles anymore.
On February 5, 2016, the Chinese company Haers Vacuum Containers announced it acquired the bottle manufacturer for 16.1 million Swiss franc ($16.02 million).
Interchangeability.
All Sigg bottles use the same diameter head and thread system, which results in interchangeability of bottles and caps. Different cap styles exist, such as a normal screw on cap with loop, caps with glow-in-the-dark markers, sports-bottle caps and caps with added protection from dust.
Aluminum bottles.
The aluminum bottles are made by an extruding press which forms an aluminum puck into a cylinder in a single movement after which it is pressed into one of several possible bottle sizes. A separate threading ring is inserted and secured. Once the bottle has been formed, it is cleaned and the interior is sprayed with a food-compatible stove enamel which is heated while the outside is coated and heat bonded with powder paint.
Aluminum bottles are resistant to shocks and disformations, are lightweight, and protect the contents from light. The interior coating is flexible and is unlikely to break or crack during deformations. Sigg bottles have been determined by Backpacker magazine to be the "world's toughest water bottle" when they fired golf balls at the water bottles with a 100-pound cannon.
The bottle with its internal liner and secure cap allow for carbonated beverages to be transported secure and freshly. All Sigg bottles manufactured after August 2008 use the "EcoCare" liner, which Sigg states is 'made from BPA-free and phthalate-free ingredients'.
The disadvantage of thin aluminum is that it does not offer much insulation, which means that condensation can build on the outside of the bottle when cold drinks are transported, and hot drinks will result in a bottle which cannot be comfortably touched. Sigg sells insulating sleeves that protect the bottle from dents, help insulate the beverages inside them and eliminate the condensation issue. The limited size of the opening also makes it difficult to fill or clean the bottle or to use it for purposes other than drinking, though Sigg now makes wide-mouth bottles, and adapters that allow the use of the standard-size caps. Aluminum bottles are also more prone to dents than stainless steel bottles. Another disadvantage is that the bottles are unsuitable for freezing its contents, as freezing liquids expand in volume and cause the bottle to crack. Therefore, it is advisable not to keep fluids in the container during extended periods below freezing temperatures.
Stainless steel bottles.
In 2013 SIGG introduced a new material into its collection, stainless steel. With the Hot & Cold line made of stainless steel SIGG offers a solution for insulated bottles. These bottles have a double wall vacuum insulation which allows them to keep temperatures, cold or hot, during several hours. One advantage of these bottles is that they do not need an inner liner to protect the liquids and they are more resistant against dents and scratches than the aluminum bottles.
Polypropylene bottles.
Since April 2014 SIGG started manufacturing bottles made of high-grade 100% recyclable polypropylene, a safe, durable and eco-friendly plastic. As part of the philosophy of the company means to keep the swissness of its products, the SIGG VIVA bottles are produced in Switzerland. SIGG ensures that these bottles are free of BPA and they are produced with the same ecological standards of the aluminum bottles. These sport orientated bottles have the advantage that they are transparent allowing to see the inside and they are very resistant against dent and scratches.
Glass bottle.
In 2015 SIGG the Swiss company enlarged its portfolio of product materials with presented a new bottle made of glass. The bottle consists of two walls of heat-resistant borosilicate glass, a WMB (wide mouth bottle) opening to allow for the addition of ice cubes, and two removable silicone elements: a grip around the body of the bottle and a base stand with shock-absorbing strips. These elements protect the fingers and prevent the bottle from breaking by being knocked or set down too heavily. The two separate glass walls provide optimal insulation, so cold drinks stay cool (for up to two hours) and hot drinks stay pleasantly warm (for up to one hour). The bottle can be comfortably handled even when it contains hot drinks and the outer wall does not build up condensation when it contains cold ones. The liquid only comes into contact with glass and stainless steel so its flavor remains unaffected. All the materials used for the bottle are BPA and BPS free.
Design.
Each year, new designs of the Sigg bottle are added to the collection while others are no longer produced. The design of Sigg bottle has led to its addition to the permanent design collection of the New York Museum of Modern Art. The classic bottle is of a single colour (most often red) whilst more modern bottles can have designs on them and are available in both glossy or matte finishes.


Langdon's Legacy

Langdon's Legacy is a lost 1916 silent comedy-drama film directed by Otis Turner and starring J. Warren Kerrigan and Lois Wilson. It was produced and distributed by Universal Film Manufacturing Company.


The Bugler of Algiers

The Bugler of Algiers is a lost 1916 silent film drama directed by Rupert Julian. It was produced by Universal's Bluebird Photoplays division and distributed by Universal Film Manufacturing Company.
Cast.
"unbilled"


Off-axis illumination

In photolithography, off-axis illumination is an optical system setup in which the incoming light strikes a photomask at an oblique angle rather than perpendicularly to it, that is to say, the incident light is not parallel to the axis of the optical system.
The advantages of off-axis illumination can be explained in the context where the pattern on the photomask is a diffraction grating with a small pitch. The light that strikes the diffraction grating is diffracted in various directions. If the light is incident on the grating at the normal angle (along the axis of the optical system), then the zero-th diffracted order light continues to propagate along the optical system axis (as if just passing through the grating without being affected), while the other diffraction orders are diffracted sideways, with the amount of angular deviation increasing as the pitch of the grating is decreasing. (In other words, the light of a non-zero diffraction order propagates from the diffraction grating at a larger angle with respect to the grating optical axis if the grating structure is finer.) For a sufficiently small pitch, only the 0th diffraction order manages to make it through the projection lens (as a lithography machine optical component that images the pattern on the photomask to a photoresist layer on a wafer), with the other orders being lost due to a limited size of the lens (which manufacturing cost goes up as its size becomes larger). The result is that no pattern is created on the wafer, since the 0th diffraction order only contains the average of the photomask pattern.
By making the off-axis illumination (i.e., the light is illuminating the mask at an oblique angle), all the diffraction orders from the mask are tilted, which makes it more likely that the higher diffraction orders can make it through the projection lens and help form the image of the mask onto the wafer.


Position-sensing hydraulic cylinder

A position-sensing hydraulic cylinder is a cylinder with a capability to track its position.
"Smart" hydraulic cylinders.
Internal LDT.
In-cylinder Linear Displacement Transducers (LDTs) are used in mobile equipment. A limitation to most in-cylinder LDTs is that the hydraulic cylinder’s piston rod must be bored through its center to accommodate certain elements of the LDT — usually the waveguide tube of a magnetostrictive transducer. The machining and additional production steps associated with “gun drilling” the piston rod can add cost to the finished cylinder. And although magnetostrictive LDTs provide extremely high accuracy, this accuracy usually is much greater than is needed for most mobile equipment applications.
Installing linear position sensors into hydraulic cylinders complicates the production process. CPI has developed a system of sensors which can eliminate the need for gun drilling.
External LDT.
External linear displacement transducers (LDTs) eliminate the need for a hollow hydraulic cylinder rod. Instead, an external sensing “bar” utilizing Hall-Effect technology senses the position of the hydraulic cylinder piston. This is accomplished by the placement of a permanent magnet within the piston. The magnet propagates a magnetic field through the steel wall of the hydraulic cylinder, providing a locating signal to the sensor.
Advantages of External LDT:


WorkNC

WorkNC is a Computer aided manufacturing (CAM) software developed by Sescoi for multi-axis machining.
History.
The first version of WorkNC CAM software was released by Sescoi, in 1988. The driving forces behind the product were Bruno Marko, president of Sescoi, and Gerard Billard, R&D Innovation Manager.
Salomon Group was the first customer to use WorkNC in 1988 in order to manufacture ski boots and other sports equipment.
In 2002 the company released WorkNC-CAD, followed by WorkNC 5-axis in 2003 and WorkNC G3 in 2007.
In 2008 Sescoi launched WorkXPlore 3D, a collaborative viewer for 3D CAD files that didn't require the original CAD application.
In 2009 the company launched WorkNC Dental, a CAD/CAM software for machining of prosthetic appliances, implants or dental structures, as well as WorkNC Wire EDM, a software for Wire EDM.
In 2010 Sescoi launched WorkNC-CAD Hybrid Modeling, a 3D CAD software for 3D model design, reparation, machining preparation, and surface design capabilities.
In 2010 Sescoi introduced WorkNC Version 21, a 64-bit version with multi-threadingl.
Functionality.
WorkNC CAM main functions include:
Supported CAD formats.
WorkNC can read the following CAD file formats:
Products.
WorkNC Dental.
Automatic machining of prosthetic appliances, implants, crowns, bridge implants and dental structures.
Intelligence within the system considers the limitations of the machine tool to automatically produce collision free toolpaths.
WorkNC MPM (Multi-Part Machining).
A CAD/CAM module that allows multiple parts to be simultaneously machined on the same machine.
WorkNC LMP (Layer Milling Process).
WorkNC LMP is a CAD/CAM software for cutting parts in layers, a well-known technique for machining deep and narrow cavities.
WorkNC-LMP automatically divides 3D models and creates roughing and finishing toolpaths for each layer. This technology can be used on any machining center, simplifying the programming and cutting of complex shapes by building them up in manageable sections.
Sescoi worked in collaboration with F. Zimmermann, combining the speed and accuracy of the dedicated Zimmermann LMC (Layer Milling Centre) with Sescoi's WorkNC-LMP. By using the software in conjunction with the machine all the toolpaths and special machine control sequences are automatically generated to cut parts in unmanned operation.
The LMC works from underneath, using high-speed techniques to machine each layer in turn. As each layer is roughed and finished a new plate is bonded, ready for the next machining operation, this continues until the finished part is built up. WorkNC-LMP automates this process starting from the CAD model, firstly splitting it into layers, and then generating both the roughing and finishing toolpaths for each layer. This technique is ideal for high speed machining enabling the use of short and rigid cutters, and eliminates the possibility of a collision. WorkNC-LMP allows to select the material from a materials library and controls factors such as surface roughening prior to bonding, cutting adhesive channels to control excess glue, overlapping of cutter paths to remove traces of glue, and paths for the application of adhesive between layers. It provides the visual control of all toolpaths and the calculation of the estimated total machining time.
WorkNC-LMP combines the advantages of generative rapid prototyping with conventional machining, and is the latest example of the company's resolve to make new processes a reality for its customers.
WorkNC Wire EDM.
WorkNC Wire EDM is a CAD/CAM software for Wire Electrical discharge machining. Dialog boxes guide the user through the system. Functions within WorkNC Wire EDM allow the extraction of cross sections, ready for 2- or 4-axis cutting. Alternatively, the 3D surfaces of the CAD model can be used directly.
It also includes graphical verification to automatically check for collisions and the maximum wire angle possible on each individual EDM machine. The latest version makes it easy to extract and link 4-axis wire paths. Dialog boxes guide the user through the process making it simple to add tags, create roughing and finishing wire paths, lead in and out moves, a range of corner strategies, and tag removal cycles. Postprocessors and technology libraries are included for all leading machines.
WorkNC-CAD.
WorkNC-CAD is a manufacturing CAD software with surface and solid modeling functions. It is included free as a standard integrated component of WorkNC. It provides features required to design and manufacture molds, dies, and tooling without the need for additional software applications or outsourcing.
WorkNC-CAD has advanced intelligent surface morphing for filling simple or complex cavities, automatic 2D feature recognition and cycle definition for drilling, counterboring, reaming and tapping, as well as automatic mold and die core separation.
WorkNC-CAD Hybrid Modeling.
WorkNC-CAD Hybrid Modeling (HM) is a 3D CAD software launched by Sescoi in 2010 for 3D model design, reparation and machining preparation, with surface design capabilities integrated with solid modeling functionality in a user friendly environment. It can be used as an independent CAD product. It is powered by D-Cubed software components from Siemens PLM.
WorkNC-CAD HM works on solid and surface models making use of parametric commands to easily manipulate and repair CAD data. Along with multiple CAD translators, it includes modules for electrode creation, core/cavity separation and Wire EDM. The WorkNC Electrode module makes use of the WorkNC-CAD Hybrid Modeling capabilities to extract electrode shapes directly from solid or surface models. The electrode model can be modified and extended, and tool holders added from a library to produce a complete electrode. WorkNC's collision checking ensures the electrode does not collide with any surrounding surfaces, automatically adding extensions as required. Documentation and electrode coordinate systems are produced by the software to ensure correct positioning for the EDM operations.
WorkNC-CAD Hybrid Modeling features include:
When used in its standalone design version by toolmakers in their technical departments, it offers mold, tool and die businesses a uniform CAD product throughout the entire manufacturing process.
WorkXPlore 3D.
WorkXPlore 3D is a 3D viewer for CAD files. A free viewer version and a free evaluation version are available.


Critical Manufacturing

Critical Manufacturing is a subsidiary of ASM Pacific Technology Limited (ASMPT). It was founded in 2008 and is focused on providing automation and manufacturing software for high-tech industries, such as photovoltaics, electronics and semiconductors. It has offices in Portugal, USA, Germany and China. In 2018, it became a subsidiary of ASM Pacific Technology Limited.
Products.
The company flagship product is Critical Manufacturing MES, a next-generation manufacturing operations management system.
Critical Manufacturing MES uses technologies from Microsoft, providing an Internet application user experience.


KORS (shoe factory)

KORS (also Novosibirsk Shoe Factory, Leather and Shoe Factory named after Kirov) is a shoe factory in Novosibirsk, Russia. It was founded in 1934.
History.
The shoe factory was founded in 1934 in Novosibirsk. In 1935 it occupied the building of the former Military Rusk Plant.
During the Great Patriotic War, the factory produced about 7 million pairs of boots for sailors and soldiers; during this period, the enterprise also manufactured ski bindings, mine casings, etc.
In 1969 the shoe factory produced over 6 million pairs of shoes (187 models).
In 1970–1980 the factory maintained economic ties with India, China, Vietnam, Italy and Yugoslavia.
In 1972 and 1984 the plants of hard and chrome leather were reconstructed.
In 1988, injection molding machines were put into operation, thanks to which an additional 750 thousand pairs of shoes were manufactured.
In the 1990s, the factory was re-equipped. Computer technology appeared at the enterprise.
Culture.
In 1935, the House of Culture named after Kirov was created at the factory. In 1937, the Museum of Labor and Military Glory was founded.
Even before the Great Patriotic War, the "Kirovsky Udarnik" newspaper began to be published. In 1956, the "Tribuna" nespaper appears. Since 1995, the factory begins to publish a newsletter.


Anti-roll bar

An anti-roll bar (roll bar, anti-sway bar, sway bar, stabilizer bar) is a part of many automobile suspensions that helps reduce the body roll of a vehicle during fast cornering or over road irregularities. It connects opposite (left/right) wheels together through short lever arms linked by a torsion spring. An anti-roll bar increases the suspension's roll stiffness—its resistance to roll in turns—independent of its spring rate in the vertical direction. The first stabilizer bar patent was awarded to Canadian inventor Stephen Coleman of Fredericton, New Brunswick on April 22, 1919.
Anti-roll bars were unusual on pre-WW2 cars due to the generally much stiffer suspension and acceptance of body roll. From the 1950s on, however, production cars were more commonly fitted with anti-roll bars, especially those vehicles with softer coil spring suspension.
Purpose and operation.
An anti-sway or anti-roll bar is intended to force each side of the vehicle to lower, or rise, to similar heights, to reduce the sideways tilting (roll) of the vehicle on curves, sharp corners, or large bumps. With the bar removed, a vehicle's wheels can tilt away by much larger distances, as shown in the SUV image at right. Although there are many variations in design, a common function is to force the opposite wheel's shock absorber, spring, or suspension rod to lower or rise to a similar level as the other wheel.
In a fast turn, a vehicle tends to drop closer onto the outer wheels, and the anti-roll bar soon forces the opposite wheel to also get closer to the vehicle. As a result, the vehicle tends to "hug" the road closer in a fast turn, where all wheels are closer to the body. After the fast turn, then the downward pressure is reduced, and the paired wheels can return to their normal height against the vehicle, kept at similar levels by the connecting anti-roll bar.
Because each pair of wheels is cross-connected by a bar, the combined operation causes all wheels to generally offset the separate tilting of the others and the vehicle tends to remain level against the general slope of the terrain.
Principles.
An anti-roll bar is usually a torsion spring that resists body roll motions. It is usually constructed out of a cylindrical steel bar, formed into a "U" shape, that connects to the body at two points, and at the left and right sides of the suspension. If the left and right wheels move together, the bar rotates about its mounting points. If the wheels move relative to each other, the bar is subjected to torsion and forced to twist. Each end of the bar is connected to an "end link" through a flexible joint. The anti-roll bar end link connects in turn to a spot near a wheel or axle, transferring forces from a heavily loaded axle to the opposite side.
Forces are therefore transferred:
The bar resists the torsion through its stiffness. The stiffness of an anti-roll bar is proportional to the stiffness of the material, the fourth power of its radius, and the inverse of the length of the lever arms (i.e., the shorter the lever arm, the stiffer the bar). Stiffness is also related to the geometry of the mounting points and the rigidity of the bar's mounting points. The stiffer the bar, the more force required to move the left and right wheels relative to each other. This increases the amount of force required to make the body roll.
In a turn the sprung mass of the vehicle's body produces a lateral force at the centre of gravity (CG), proportional to lateral acceleration. Because the CG is usually not on the roll axis, the lateral force creates a moment about the roll axis that tends to roll the body. (The roll axis is a line that joins the front and rear roll centers). The moment is called the roll couple.
Roll couple is resisted by the suspension roll stiffness, which is a function of the spring rate of the vehicle's springs and of the anti-roll bars, if any. The use of anti-roll bars allows designers to reduce roll without making the suspension's springs stiffer in the vertical plane, which allows improved body control with less compromise of ride quality.
One effect of body (frame) lean, for typical suspension geometry, is positive camber of the wheels on the outside of the turn and negative on the inside, which reduces their cornering grip (especially with cross ply tires).
Main functions.
Anti-roll bars provide two main functions. The first function is the reduction of body lean. The reduction of body lean is dependent on the total roll stiffness of the vehicle. Increasing the total roll stiffness of a vehicle does not change the steady state total load (weight) transfer from the inside wheels to the outside wheels, it only reduces body lean. The total lateral load transfer is determined by the CG height and track width.
The other function of anti-roll bars is to tune the handling balance of a car. Understeer or oversteer behavior can be tuned out by changing the proportion of the total roll stiffness that comes from the front and rear axles. Increasing the proportion of roll stiffness at the front increases the proportion of the total load transfer that the front axle reacts to—and decreases the proportion that the rear axle reacts to. In general, this makes the outer front wheel run at a comparatively higher slip angle, and the outer rear wheel to run at a comparatively lower slip angle, which is an understeer effect. Increasing the proportion of roll stiffness at the rear axle has the opposite effect and decreases understeer.
Drawbacks.
Because an anti-roll bar connects wheels on opposite sides of the vehicle, the bar transmits the force of a bump on one wheel to the opposite wheel. On rough or broken pavement, anti-roll bars can produce jarring, side-to-side body motions (a "waddling" sensation), which increase in severity with the diameter and stiffness of the anti-roll bars. Other suspension techniques can delay or dampen this effect of the connecting bar.
Excessive roll stiffness, typically achieved by configuring an anti-roll bar too aggressively, can make the inside wheels lift off the ground during hard cornering. This can be used to advantage: many front wheel drive production cars lift a rear wheel when cornering hard in order to overload the opposite wheel, limiting understeer.
Adjustable bars.
Some anti-roll bars, particularly those intended for use in auto racing, are externally adjustable while the car is in the pit whereas some systems can be adjusted in real time by the driver from inside the car, such as in Super GT. This allows the stiffness to be altered, for example by increasing or reducing the length of the lever arms on some systems, or by rotating a flat lever arm from a stiff edge-on position to a more flexible flat-side-on position on other systems. This lets a mechanic tune the roll stiffness for different situations without replacing the entire bar.
MacPherson struts.
The MacPherson strut is a common form of strut suspension. This was not the first attempt at strut suspension, but in MacPherson's original patent, the anti-roll bar forms an integral and essential part of the suspension, in addition to its usual function in controlling body roll. A strut suspension like MacPherson's requires a hinged lower member between the chassis and wheel hub to control the wheel position both inwards and outwards (controlling the track), and also forwards and backwards. This may be provided by a wishbone with a number of joints, or by using an additional radius rod. MacPherson's design replaced the wishbone with a simpler and cheaper track control arm, with a single inboard joint, to control the track. Forward and backward position was controlled through the anti-roll bar. Overall this required a simpler and cheaper set of suspension members than with wishbones, also allowing a reduction in unsprung weight.
As the anti-roll bar is required to control wheel position, the bars of a MacPherson strut suspension may be connected through ball joints. However many later "MacPherson strut" suspensions have reverted to using wishbones rather than the simplified track control arm of the original design.
Semi active anti-roll bars.
Various methods of decoupling the anti-roll bar have been proposed. The first production car to use an active anti-roll bar was the 1988 Mitsubishi Mirage Cyborg. The "Dual Mode Suspension" equipped with the 16-v turbo model has front active anti-roll bar that has a hydraulic actuator built in the anti-roll bar link. The actuator can be operated with a switch on the dash board, changing the effectiveness of the anti-roll bar between the sport mode and touring mode. The Jeep Wrangler (JK, JL) and Jeep Gladiator (JT) also have a switchable decoupler on Rubicon models, to increase wheel articulation for off-roading.
Active systems.
The first car to use an active anti-roll bar in 1994 was the Citroën Xantia Activa, a medium-sized sedan sold in Europe. The SC.CAR (Systeme Citroën de Contrôle Actif du Roulis) system featured an anti-roll bar that could be stiffened under the command of the suspension ECU during hard cornering. The car rolled a maximum of 2 degrees.
In 2001 the BMW 7 Series (E65) introduced Active Roll Stabilization (ARS) "active" anti-roll bars that can be proportionally controlled automatically by a suspension-control computer, reducing body lean in turns while improving rough-road ride quality.
In 2006 Toyota introduced its Active Stabilizer Suspension System. By altering anti-roll bar stiffness, this system acts to reduce body tilt during cornering, keeping the vehicle more level during turns and improving handling, as opposed to the natural tendency of a vehicle to roll due to the lateral forces experienced during high-speed maneuvering. The active stabilizer system relies on vehicle body sensors and electric motors. The first production usage of this system was introduced in August 2005 with the Lexus GS430 sport sedan.
Porsche Cayenne introduced Porsche Dynamic Chassis Control (PDCC), a system with active roll-bars in 2007 (on European market).
In 2011, the third generation Mercedes-Benz M-Class introduced a similar system: ACTIVE CURVE SYSTEM.
Range Rover Sport introduced Dynamic Response active anti-roll bars.
Mercedes-Benz S-Class Active Body Control system uses another approach: the computer uses sensors to detect lateral load, lateral force, and height difference in the suspension strut, then uses hydraulic pressure to raise or lower the spring to counter roll. This system removes the anti-roll bar. Most active roll control systems allow a small degree of roll to give a more natural feel.
Toyota also uses a mechanical system called Kinetic Dynamic Suspension System (KDSS) that essentially disengages the stabilizer bars when off-road, allowing for greater vehicle articulation and ride quality.


Oramir

Oramir Semiconductor Equipment Ltd. is an Israeli company that develops advanced laser cleaning technologies for semiconductor wafers, used during their manufacturing process. Oramir is located in Rehovot, Israel.
History.
Oramir was founded in 1992 by Fairchild Corporation, Teuza Venture Capital Fund and Rafael Development Corporation of Israel. Oramir was named after Amir Sinai who was killed in service as an IDF special unit NCO in July 1984, during the war in Lebanon. Dan Sinai, Amir's father, was one of Oramir's founders.
Oramir’s notability derives from developing the advanced technology for cleaning silicon wafers in a one step dry process. Particles and other contaminants can be removed from a silicon substrate by a patented laser based technology. Applied Materials Inc. (NASDAQ: AMAT), a semiconductor equipment manufacturer, acquired Oramir for $21 million on June 27, 2001.


Industrial symbiosis

Industrial symbiosis a subset of industrial ecology. It describes how a network of diverse organizations can foster eco-innovation and long-term culture change, create and share mutually profitable transactions—and improve business and technical processes.
Although geographic proximity is often associated with industrial symbiosis, it is neither necessary nor sufficient—nor is a singular focus on physical resource exchange. Strategic planning is required to optimize the synergies of co-location. In practice, using industrial symbiosis as an approach to commercial operations—using, recovering and redirecting resources for reuse—results in resources remaining in productive use in the economy for longer. This in turn creates business opportunities, reduces demands on the earth's resources, and provides a stepping-stone towards creating a circular economy.
Industrial symbiosis is a subset of industrial ecology, with a particular focus on material and energy exchange. Industrial ecology is a relatively new field that is based on a natural paradigm, claiming that an industrial ecosystem may behave in a similar way to the natural ecosystem wherein everything gets recycled, albeit the simplicity and applicability of this paradigm has been questioned.
Introduction.
Eco-industrial development is one of the ways in which industrial ecology contributes to the integration of economic growth and environmental protection. Some of the examples of eco-industrial development are:
Industrial symbiosis engages traditionally separate industries in a collective approach to competitive advantage involving physical exchange of materials, energy, water, and/or by-products. The keys to industrial symbiosis are collaboration and the synergistic possibilities offered by geographic proximity". Notably, this definition and the stated key aspects of industrial symbiosis, i.e., the role of collaboration and geographic proximity, in its variety of forms, has been explored and empirically tested in the UK through the research and published activities of the National Industrial Symbiosis Programme.
Industrial symbiosis systems collectively optimize material and energy use at efficiencies beyond those achievable by any individual process alone. IS systems such as the web of materials and energy exchanges among companies in Kalundborg, Denmark have spontaneously evolved from a series of micro innovations over a long time scale; however, the engineered design and implementation of such systems from a macro planner's perspective, on a relatively short time scale, proves challenging.
Often, access to information on available by-products is difficult to obtain. These by-products are considered waste and typically not traded or listed on any type of exchange. Only a small group of specialized waste marketplaces addresses this particular kind of waste trading.
Example.
Recent work reviewed government policies necessary to construct a multi-gigaWatt photovoltaic factory and complementary policies to protect existing solar companies are outlined and the technical requirements for a "symbiotic industrial system" are explored to increase the manufacturing efficiency while improving the environmental impact of solar photovoltaic cells. The results of the analysis show that an eight-factory industrial symbiotic system can be viewed as a medium-term investment by any government, which will not only obtain direct financial return, but also an improved global environment.
This is because synergies have been identified for co-locating glass manufacturing and photovoltaic manufacturing.
The waste heat from glass manufacturing can be used in industrial-sized greenhouses for food production. Even within the PV plant itself a secondary chemical recycling plant can reduce environmental impact while improving economic performance for the group of manufacturing facilities.
In DCM Shriram consolidated limited (Kota unit) produces caustic soda, calcium carbide, cement and PVC resins. Chlorine and hydrogen are obtained as by-products from caustic soda production, while calcium carbide produced is partly sold and partly is treated with water to form slurry(aqueous solution of calcium hydroxide) and ethylene. The chlorine and ethylene produced are utilised to form PVC compounds, while the slurry is consumed for cement production by wet process. Hydrochloric acid is prepared by direct synthesis where the pure chlorine gas can be combined with hydrogen to produce hydrogen chloride in the presence of UV light.


Automatic lubrication system

An automatic lubrication system (ALS), sometimes referred to as a centralized lubrication system (CLS), is a system that delivers controlled amounts of lubricant to multiple locations on a machine while the machine is operating. Even though these systems are usually fully automated, a system that requires a manual pump or button activation is still identified as a centralized lubrication system. The system can be classified into two different categories that can share a lot of the same components.
Oil systems: Oil systems primary use is for stationary manufacturing equipment such as CNC milling
Grease systems: Grease primary use is on mobile units such as trucks, mining or construction equipment.
Automatic lubrication systems are key aspects in maintenance and reliability programs. They supply lube points with metered amounts of grease or oil from a central location. The pump supplies the system with the chosen lubricant and is fed from a reservoir that is easily accessible. Depending on the application, the reservoir ranges in size and can be as small as 2 liters all the way up to an intermediate bulk container or even a bulk tank. The options are almost limitless and are application-specific. These systems have the option to be monitored remotely with feedback and can be tied directly into your plant's PLC. So whether you're running an excavator, driving a ready-mix truck, operating a crusher, or making steel, you can rest assured that your assets are being properly lubricated at all times.
Reasons for Automatic Lubrication Systems.
Automatic lubrication systems or centralized lubrication system s are designed to apply lubricant in precise, metered amounts over short, frequent time intervals. Time and human resource constraints and often the physical location on the machine often makes it impractical to manually lubricate the points. As a result, production cycles, machine availability, and manpower availability dictate the intervals at which machinery is lubricated, which is not optimal for the point requiring lubrication. Automatic lubrication systems are installed on machinery to circumvent these issues.
Benefits.
Auto lube systems have many advantages over traditional methods of manual lubrication:
Components.
A typical system consists of controller/timer, pump w/reservoir, supply line, metering valves, and feed lines. Regardless of the manufacturer or type of system, all automatic lubrication systems share these 5 main components:
Types.
There are several different types of automatic lubrication systems including:
The 4 most commonly used Automatic Lubrication System types are:
Single line progressive.
A single line progressive system uses lubricant flow to cycle individual metering valves and valve assemblies. The valves consist of dispensing pistons moving back and forth in a specific bore. Each piston depends on flow from the previous piston to shift and displace lubricant. If one piston doesn't shift, none of the following pistons will shift. Valve output is not adjustable.
Operation begins when the controller/timer sends a signal to the pump to start the lube event. The pump then feeds lubricant into the supply line which connects to the primary metering valve, for either a preprogrammed amount of time or number of times as monitored through a designated piston cycle switch. Lubricant is fed to the multiple lubrication points one after another via secondary progressive metering valves sized for each series of lubrication points, and then directly to each point via the feed lines.
Single line parallel.
The first single-line parallel system for industry was introduced in 1937 by Lincoln Engineering (now known as Lincoln Industrial) in the United States.
A single line parallel system can service a single machine, different zones on a single machine or even several separate machines and is ideal when the volume of lubricant varies for each point. In this type of system, a central pump station automatically delivers lubricant through a single supply line to multiple branches of injectors. Each injector serves a single lubrication point, operates independently and may be individually adjusted to deliver the desired amount of lubricant.
Operation begins when the controller/timer sends a signal to the pump starting the lube cycle. The pump begins pumping lubricant to build up pressure in the supply line connecting the pump to the injectors. Once the required pressure is reached, the lube injectors dispense a predetermined amount of lubricant to the lubrication points via feed lines.
Once the entire system reaches the required pressure, a pressure switch sends a signal to the controller indicating that grease has cycled through to all the distribution points. The pump shuts off. Pressure is vented out of the system and grease in the line is redirected back to the pump reservoir, until the normal system pressure level is restored.
Dual line parallel.
A dual line parallel system is similar to the single line parallel system in that it uses hydraulic pressure to cycle adjustable valves to dispense measured shots of lubricant. It has 2 main supply lines which are alternatively used as pressure / vent lines. The advantage of a two-line system is that it can handle hundreds of lubrication points from a single pump station over several thousand feet using significantly smaller tubing or pipe.
Operation begins when the controller/timer sends a signal to the pump to start the lubrication cycle. The pump begins pumping lubricant to build up pressure in the first (the pressure) supply line while simultaneously venting the second (vent) return line. Once the required pressure is reached, a predetermined amount of lubricant is dispensed by the metering devices to half of the lubrication points via feed lines.
Once the pressure switch monitoring main supply line pressure indicates a preset pressure in the line has been reached, the system is hydraulically closed. The controller shuts off the pump and signals a changeover valve to redirect lubricant to the second main supply line.
The next time the controller activates the system, the second main line now becomes the pressure line while the first line becomes the vent line. The second line is pressurized and the entire process is repeated lubricating the remaining lube points.
Multi point direct lubricator
When the controller in the pump or external controller activates the drive motor, a set of cams turns and activates individual injectors or pump elements to dispense a fixed amount of lubricant to each individual lubrication point. Systems are easy to design, direct pump to lube point without added accessories and easy to troubleshoot.


Polishing (metalworking)

Polishing and buffing are finishing processes for smoothing a workpiece's surface using an abrasive and a work wheel or a leather strop. Technically, "polishing" refers to processes that uses an abrasive that is glued to the work wheel, while "buffing" uses a loose abrasive applied to the work wheel. Polishing is a more aggressive process, while buffing is less harsh, which leads to a smoother, brighter finish. A common misconception is that a polished surface has a mirror-bright finish, however, most mirror-bright finishes are actually buffed.
Polishing is often used to enhance the appearance of an item, prevent contamination of instruments, remove oxidation, create a reflective surface, or prevent corrosion in pipes. In metallography and metallurgy, polishing is used to create a flat, defect-free surface for examination of a metal's microstructure under a microscope. Silicon-based polishing pads or a diamond solution can be used in the polishing process. Polishing stainless steel can also increase its sanitary benefits.
The removal of oxidization (tarnish) from metal objects is accomplished using a metal polish or tarnish remover; this is also called polishing. To prevent further unwanted oxidization, polished metal surfaces may be coated with wax, oil, or lacquer. This is of particular concern for copper alloy products such as brass and bronze.
While used less extensively than traditional mechanical polishing, electropolishing is an alternative form of polishing that uses the principles of electrochemistry to remove microscopic layers of metal from a base surface. This method of polishing can be fine-tuned to give a wide range of finishes, from matte to mirror-bright. Electropolishing also has an advantage over traditional manual polishing in that the finished product will not experience the compression and deformation traditionally associated with the polishing process.
Process.
The condition of the material at hand determines what type of abrasive will be applied. The first stage, if the material is unfinished, starts with a rough abrasive (perhaps 60 or 80 grit) and each subsequent stage uses a finer abrasive, such as 120, 180, 220/240, 320, 400 and higher grit abrasives, until the desired finish is achieved. The rough (i.e. large grit) passes remove imperfections within the metal surface like pits, nicks, lines and scratches. The finer abrasives leave progressively finer lines that are not visible to the naked eye. A no. 8 ("mirror") finish requires polishing and buffing compounds, and polishing wheels attached to high speed polishing machines or electric drills. Lubricants like wax and kerosene may be used as lubricating and cooling media during these operations, although some polishing materials are specifically designed to be used "dry." Buffing may be done by hand with a stationary polisher or die grinder, or it may be automated using specialized equipment.
When buffing there are two types of buffing motions: the "cut motion" and the "color motion". The cut motion is designed to give a uniform, smooth, semi-bright surface finish. This is achieved by moving the workpiece against the rotation of the buffing wheel, while using medium to hard pressure. The color motion gives a clean, bright, shiny surface finish. This is achieved by moving the workpiece with the rotation of the buffing wheel, while using medium to light pressure.
When polishing brass (a softer metal) there are often minute marks in the metal caused by impurities. To smooth out the finer marks, the surface is polished with a very fine (600) grit, copper plated, then buffed to a mirror finish with an airflow mop.
Polishing operations for items such as chisels, hammers, screwdrivers, wrenches, etc., are given a fine finish but not plated. In order to achieve this finish four operations are required: roughing, dry fining, greasing, and coloring. Note that roughing is usually done on a solid grinding wheel and for an extra fine polish the greasing operation may be broken up into two operations: rough greasing and fine greasing. However, for inexpensive items money is saved by only performing the first two operations.
Polishing knives and cutlery is known as fine glazing or blue glazing. Sand buffing, when used on German silver, white metal, etc., is technically a buffing operation because it uses a loose abrasive, but removes a significant amount of material, like polishing.
Equipment.
White and grey aluminium oxide abrasives are used on high tensile strength metals, such as carbon and alloy steel, tough iron, and nonferrous alloys. Gray silicon carbide abrasives are used on hard and brittle substances, such as grey iron and cemented carbide, and low tensile strength metals, such as brass, aluminium, and copper. Green chromium(III) oxide is the abrasive used in green compounds that are typically used to finish ferrous metals (steels).
Polishing wheels come in a wide variety of types to fulfil a wide range of needs. The most common materials used for polishing wheels are wood, leather, canvas, cotton cloth, plastic, felt, paper, sheepskin, impregnated rubber, canvas composition, and wool; leather and canvas are the most common. Wooden wheels have emery or other abrasives glued onto them and are used to polish flat surfaces and maintain good edges. There are many types of cloth wheels. Cloth wheels that are cemented together are very hard and used for rough work, whereas other cloth wheels that are sewn and glued together are not as aggressive. There are cloth wheels that are not glued or cemented, and instead are sewn and have metal side plates for support. Solid felt wheels are popular for fine finishes. Hard roughing wheels can be made by cementing together strawboard paper disks. Softer paper wheels are made from felt paper. Most wheels are run at approximately 7500 surface feet per minute (SFM), however muslin, felt and leather wheels are usually run at 4000 SFM.
Buffing wheels, also known as mops, are either made from cotton or wool cloth and come bleached or unbleached. Specific types include: sisal, spiral sewn, loose cotton, canton flannel, domet flannel, denim, treated spiral sewn, cushion, treated vented, untreated vented, string buff, finger buff, sisal rope, mushroom, facer, tampered, scrubbing mushroom, hourglass buff, rag, "B", climax, swansdown, airflow, coolair, and bullet.
The following chart will help in deciding which wheels and compounds to use when polishing different materials. This chart is a starting point and experienced polishers may vary the materials used to suit different applications.
Applications.
Polishing may be used to enhance and restore the looks of certain metal parts or object on cars and other vehicles, handrails, cookware, kitchenware, and architectural metal. In other applications such as pharmaceutical, dairy, and specialty plumbing, pipes are buffed to help prevent corrosion and to eliminate locations where bacteria or mold may reside. Buffing is also used to manufacture light reflectors.


Tolerance analysis

Tolerance analysis is the general term for activities related to the study of accumulated variation in mechanical parts and assemblies. Its methods may be used on other types of systems subject to accumulated variation, such as mechanical and electrical systems. Engineers analyze tolerances for the purpose of evaluating geometric dimensioning and tolerancing (GD&T). Methods include 2D tolerance stacks, 3D Monte Carlo simulations, and datum conversions.
Tolerance stackups or tolerance stacks are used to describe the problem-solving process in mechanical engineering of calculating the effects of the accumulated variation that is allowed by specified dimensions and tolerances. Typically these dimensions and tolerances are specified on an engineering drawing. Arithmetic tolerance stackups use the worst-case maximum or minimum values of dimensions and tolerances to calculate the maximum and minimum distance (clearance or interference) between two features or parts. Statistical tolerance stackups evaluate the maximum and minimum values based on the absolute arithmetic calculation combined with some method for establishing likelihood of obtaining the maximum and minimum values, such as Root Sum Square (RSS) or Monte-Carlo methods.
Modeling.
In performing a tolerance analysis, there are two fundamentally different analysis tools for predicting stackup variation: worst-case analysis and statistical analysis.
Worst-case.
Worst-case tolerance analysis is the traditional type of tolerance stackup calculation. The individual variables are placed at their tolerance limits in order to make the measurement as large or as small as possible. The worst-case model does not consider the distribution of the individual variables, but rather that those variables do not exceed their respective specified limits. This model predicts the maximum expected variation of the measurement. Designing to worst-case tolerance requirements guarantees 100 percent of the parts will assemble and function properly, regardless of the actual component variation. The major drawback is that the worst-case model often requires very tight individual component tolerances. The obvious result is expensive manufacturing and inspection processes and/or high scrap rates. Worst-case tolerancing is often required by the customer for critical mechanical interfaces and spare part replacement interfaces. When worst-case tolerancing is not a contract requirement, properly applied statistical tolerancing can ensure acceptable assembly yields with increased component tolerances and lower fabrication costs.
Statistical variation.
The statistical variation analysis model takes advantage of the principles of statistics to relax the component tolerances without sacrificing quality. Each component's variation is modeled as a statistical distribution and these distributions are summed to predict the distribution of the assembly measurement. Thus, statistical variation analysis predicts a distribution that describes the assembly variation, not the extreme values of that variation. This analysis model provides increased design flexibility by allowing the designer to design to any quality level, not just 100 percent.
There are two chief methods for performing the statistical analysis. In one, the expected distributions are modified in accordance with the relevant geometric multipliers within tolerance limits and then combined using mathematical operations to provide a composite of the distributions. The geometric multipliers are generated by making small deltas to the nominal dimensions. The immediate value to this method is that the output is smooth, but it fails to account for geometric misalignment allowed for by the tolerances; if a size dimension is placed between two parallel surfaces, it is assumed the surfaces will remain parallel, even though the tolerance does not require this. Because the CAD engine performs the variation sensitivity analysis, there is no output available to drive secondary programs such as stress analysis.
In the other, the variations are simulated by allowing random changes to geometry, constrained by expected distributions within allowed tolerances with the resulting parts assembled, and then measurements of critical places are recorded as if in an actual manufacturing environment. The collected data is analyzed to find a fit with a known distribution and mean and standard deviations derived from them. The immediate value to this method is that the output represents what is acceptable, even when that is from imperfect geometry and, because it uses recorded data to perform its analysis, it is possible to include actual factory inspection data into the analysis to see the effect of proposed changes on real data. In addition, because the engine for the analysis is performing the variation internally, not based on CAD regeneration, it is possible to link the variation engine output to another program. For example, a rectangular bar may vary in width and thickness; the variation engine could output those numbers to a stress program which passes back peak stress as a result and the dimensional variation be used to determine likely stress variations. The disadvantage is that each run is unique, so there will be variation from analysis to analysis for the output distribution and mean, just like would come from a factory.
While no official engineering standard covers the process or format of tolerance analysis and stackups, these are essential components of good product design. Tolerance stackups should be used as part of the mechanical design process, both as a predictive and a problem-solving tool. The methods used to conduct a tolerance stackup depend somewhat upon the engineering dimensioning and tolerancing standards that are referenced in the engineering documentation, such as American Society of Mechanical Engineers (ASME) Y14.5, ASME Y14.41, or the relevant ISO dimensioning and tolerancing standards. Understanding the tolerances, concepts and boundaries created by these standards is vital to performing accurate calculations.
Tolerance stackups serve engineers by:
Concept of Tolerance vector loop.
The starting point for the tolerance loop; typically this is one side of an intended gap, after pushing the various parts in the assembly to one side or another of their loose range of motion. Vector loops define the assembly constraints that locate the parts of the assembly relative to each other. The vectors represent the dimensions that contribute to tolerance stackup in the assembly. The vectors are joined tip-to-tail, forming a chain, passing through each part in the assembly in succession. A vector loop must obey certain modeling rules as it passes through a part. It must:
Additional modeling rules for vector loops include:
The above rules will vary depending on whether 1D, 2D or 3D tolerance stackup method is used.
Concerns with tolerance stackups.
A safety factor is often included in designs because of concerns about:


Tuuli Mattelmäki

Tuuli Mattelmäki (1965) is Finnish industrial designer, researcher and lecturer, working and publishing in service design and human centred design.
Tuuli Mattelmäki works as a researcher and project manager at the Aalto University School of Arts, Design and Architecture where she is an associate professor at the Department of Design. She is also a team leader at Encore: Aalto University collaborative design research project.
As an industrial designer she has applied her design thinking skills in enhancing innovative approaches that are inspired by the richness of human experiences and everyday practices.
During her research she has worked on several projects for developing tools and processes for user-centred product concept design. Starting point for her research is an empathic design and explorative methods in user-centred design, design probes in particular. She has been actively involved in several user focus case studies and collaborations with the partner companies.
Her current research concerns creative co-design methods in design for services, as well as the new application contexts of design approaches. Her research with design probes has inspired students and organisations to apply the approach in various projects.
Her publications include articles about probes, empathic design and design for user experience.
“Design Probes", her dissertation from University of Art and Design in Helsinki from 2006, presents a step-by-step overview of the cultural probes method and its history and offers nearly 200 pages of richly illustrated examples, history and theory.


Seiichi Nakajima

Seiichi Nakajima (1919–April 11, 2015) was a Japanese citizen and pioneering founder of the Total Productive Maintenance system. He established the PM Awards (currently the TPM Awards).
Nakajima was honored by the Emperor of Japan with the Ranju Ho-sho, or Medal with Blue Ribbon. The award recognizes individuals with significant lifetime achievements, and was given to Nakajima by the Emperor "to show gratitude for the dedication to improving the manufacturing industry through TPM."


Renault Sherpa 5

Renault Sherpa 5 is a tactical military truck made by Renault Trucks Defense, a subsidiary of Renault Trucks. It evolved from the Renault GBC 180.
Description.
Renault Sherpa 5 was debuted at the 2004 Eurosatory military trade fair. The vehicle is an all-wheel drive truck (in 4×4 or 6×6 configurations) that can carry a payload of seven tons. It is used for transport in war zones - the French armed forces use the truck as a chassis for the CAESAR self-propelled howitzer.


Schedule (workplace)

A schedule, often called a rota or roster, is a list of employees, and associated information e.g. location, department, working times, responsibilities for a given time period e.g. week, month or sports season.
A schedule is necessary for the day-to-day operation of many businesses e.g. retail store, manufacturing facility and some offices. The process of creating a schedule is called scheduling. An effective workplace schedule balances the needs of stakeholders such as management, employees and customers.
A "daily" schedule is usually ordered chronologically, which means the first employees working that day are listed at the top, followed by the employee who comes in next, etc. A "weekly" or "monthly" schedule is usually ordered alphabetically, employees being listed on the left hand side of a grid, with the days of the week on the top of the grid. In shift work, a schedule usually employs a recurring shift plan.
A schedule is most often created by a manager. In larger operations, a human resources manager or scheduling specialist may be solely dedicated to creating and maintaining the schedule. A schedule by this definition is sometimes referred to as workflow.
Software is often used to enable organizations to better manage staff scheduling. Organizations commonly use spreadsheet software or employee scheduling software to create and manage shifts, assignments, and employee preferences. For large organisations employee scheduling can be complex, and optimising this is framed as the nurse scheduling problem in operations Research. Advanced employee scheduling software also provides ways to connect with the staff, ask for their preferences and communicate the schedule to them.
On-call scheduling.
An oncall shift, or on-call scheduling, is a practice that requires employees to be available to be called onto last-minute shifts without pre-scheduling. In the United States, the practice has been opposed by labor rights groups as "unfair and detrimental to employees."
Self-scheduling.
Flexible self-scheduling is a practice used when a manager defines scheduling needs based on demand, but allows employees to select, trade, and fill shifts themselves. Allowing schedules to be created faster, with less effort, and gives hourly employees more control over their work life.


Store manager

A retail manager (or store manager) is the person ultimately responsible for the day-to-day operations (or management) of a retail store. All employees working in the store report to the retail/store manager. A store manager reports to a district/area or general manager.
Roles and responsibilities.
Responsibilities of a store manager include:
Sales generation.
A store manager must meet the monthly, quarterly, or annual sales goals, depending on the company's fiscal cycle. This involves setting individual sales goals (quotas), holding contests for employees, or offering sales promotions. The manager may also find ways to make employees more productive to meet the goals. Thus, the store manager may be forced to reduce payroll expenditures by decreasing employees' hours, or otherwise reducing operating cost. A store manager should motivate their team to achieve the target set for the store. A store manager should set an example for their subordinates to follow.
Safety and security.
The Store manager is the store's primary key-holder and may be called to the store before, during, or after business hours in the event of an emergency. They are also responsible for the safety of all customers and employees on store premises. Store managers may be required to hold safety meetings, especially as dictated by union practices in cases where store employees belong to a union.
Division of responsibility.
A store manager may have several subordinates who have management-level responsibility. These employees may be called deputy managers, assistant managers, department managers, supervisors, key holders, shift leads, or leads. Sometimes members of the management team may be several grades below the store manager. One example would be store manager - deputy manager - department manager - department leads.
A store manager has over-all responsibility for all day-to-day activity of the store. Managing & controlling staff, and planning are essential points of the store manager.
Hiring, training and development.
The store manager is responsible for hiring, training, and in some cases, development of employees. The manager must ensure staffing levels are adequate to effectively operate the store, and ensure employees receive training necessary for their job responsibilities. Managers may be responsible for developing employees so the company can promote employees from within and develop future leaders, potentially for employment at other locations. Store managers also have the fire powers to any under-performing or misbehaving employees. The role of store managers with regards to the other employees varies from company to company and each respective company's operating methods but in general a store manager will be required to deal with and try to solve any and all problems that may occur at any given time


Spherical roller bearing

A spherical roller bearing is a rolling-element bearing that permits rotation with low friction, and permits angular misalignment. Typically these bearings support a rotating shaft in the bore of the inner ring that may be misaligned in respect to the outer ring. The misalignment is possible due to the spherical internal shape of the outer ring and spherical rollers. Despite what their name may imply, spherical roller bearings are not truly spherical in shape. The rolling elements of spherical roller bearings are mainly cylindrical in shape, but have a (barrel like) profile that makes them appear like cylinders that have been slightly over-inflated (i.e. like a barrel).
Construction.
Spherical roller bearings consist of an inner ring with two raceways inclined at an angle to the bearing axis, an outer ring with a common spherical raceway, spherical rollers, cages and, in certain designs, also internal guide rings or center rings. These bearings can also be sealed.
History.
The spherical roller bearing was invented by engineer Arvid Palmgren and was introduced on the market 1919 by SKF. The design of the bearing that Arvid Palmgren invented is similar to the design that is still in use in modern machines.
Designs.
Most spherical roller bearings are designed with two rows of rollers, allowing them to take very heavy radial loads and heavy axial loads. There are also designs with one row of rollers, suitable for lower radial loads and virtually no axial load. These are also called "barrel roller bearings" or "Tonnenlager" and are typically available in the 202- and 203-series.
The internal design of the bearing is not standardised by ISO, so it varies between different manufacturers and different series. Some features that may or may not exist in different bearings are:
Dimensions.
External dimensions of spherical roller bearings are standardised by ISO in the standard ISO 15:1998. Some of the common series of spherical roller bearings are: 213, 222, 223, 230, 231, 232, 238, 239, 240, 241, 248, 249.
Materials.
Bearing rings and rolling elements can be made of a number of different materials, but the most common is "chrome steel", (high carbon chromium) a material with approximately 1.5% chrome content. Such "chrome steel" has been standardized by a number of authorities, and there are therefore a number of similar materials, such as: AISI 52100 (USA), 100CR6 (Germany), SUJ2 (Japan) and GCR15 (China).
Some common materials for bearing cages:
The choice of material is mainly done by the manufacturing volume and method. For large-volume bearings, cages are often of stamped sheet-metal or injection molded polyamide, whereas low volume manufacturers or low volume series often have cages of machined brass or machined steel. For some specific applications, special material for coating (e.g. PTFE coated cylindrical bore for vibratory applications) is adopted.
Manufacturers.
Some manufacturers of "spherical roller bearings" are SKF, Schaeffler, Timken Company, NSK Ltd., NTN Corporation and JTEKT.
Since SKF introduced the spherical roller bearing in 1919, spherical roller bearings have purposefully been refined through the decades to improve carrying capacity and to reduce operational friction. This has been possible by playing with a palette of parameters such as materials, internal geometry, tolerance and lubricant. Nowadays, spherical roller bearing manufacturers are striving to refine the bearing knowledge towards more environmentally-friendly and energy-efficient solutions.
Applications.
Spherical bearings are used in countless industrial applications where there are heavy loads, moderate speeds and possibly misalignment. Some common application areas are:


Harvey Rosten Award for Excellence

The Harvey Rosten Award for Excellence is an annual award celebrating a piece of work by a group or individual representing an advance in thermal analysis of electronics equipment or components. Including experiments aimed at specifically validating numerical models.
The award is named after Dr. Harvey Rosten, founder of Flomerics, in honor of the influence on the electronics cooling industry he had. The award was curated the year after his death by (1998). The award is announced at the annual SEMI-THERM conference.
To be eligible, submitted papers must be an original pieces of work as well as in the public domain. The work must also be relevant, concerning advances in thermal analysis or thermal modelling of electronics equipment or component and have clear application to practical electronics thermal design.
Criteria.
To be eligible, submitted papers must be an original pieces of work as well as in the public domain. The work must also be relevant, concerning advances in thermal analysis or thermal modelling of electronics equipment or component and have clear application to practical electronics thermal design.
Favourable consideration is administered towards papers that either demonstrate an innovative approach to embodying the understanding of the physical processes affecting the thermal behaviour of an electronics component, part or system, insights into these processes, or a practical application of the advance.


Dissimilar friction stir welding

Dissimilar friction stir welding (DFSW) is the application of friction stir welding (FSW), invented in The Welding Institute (TWI) in 1991, to join different base metals including aluminum, copper, steel, titanium, magnesium and other materials. It is based on solid state welding that means there is no melting. DFSW is based on a frictional heat generated by a simple tool in order to soften the materials and stir them together using both tool rotational and tool traverse movements. In the beginning, it is mainly used for joining of aluminum base metals due to existence of solidification defects in joining them by fusion welding methods such as porosity along with thick Intermetallic compounds. DFSW is taken into account as an efficient method to join dissimilar materials in the last decade. There are many advantages for DFSW in compare with other welding methods including low-cost, user-friendly, and easy operation procedure resulting in enormous usages of friction stir welding for dissimilar joints. Welding tool, base materials, backing plate (fixture), and a milling machine are required materials and equipment for DFSW. On the other hand, other welding methods, such as Shielded Metal Arc Welding (SMAW) typically need highly professional operator as well as quite expensive equipment.
Principle of operation.
The mechanism of DFSW is very simple. A rotating tool plunges into the interface of parent metals, and heat input generated by the friction between the tool shoulder surface and top surface of the base metals lead to softening of the base materials. In other words, the rotational movement of the tool mixes and stirs the parent metals and create a softened pasty mixture. Afterwards, the tool's traverse movement along the interface creates a joint. This results in a final bond that combines both mechanical and metallurgical bonding at the interface. These two bondings are critical in order to achieve proper mechanical properties. Butt and lap designs are the most common joint types in dissimilar friction stir welding (DFSW). Likewise, one material is generally harder than the other. In general, hard and soft materials are placed in advancing and retreating sides respectively during welding.
Tool Geometry.
Tool configuration is an important factor to achieve a sound joint. The tool consists of two parts including tool shoulder and tool pin, as shown in below figure. The tool shoulder generates frictional heat, while the tool pin stirs the softened materials. Various pin and shoulder configurations may be used for DFSW. "Cylindrical", "rectangular", "triangular" and "threaded-cylindrical" are the most common tool pin profiles, while "featureless" and "scrolled" are the most common tool shoulder configurations. Tool material selection is dependent on the base materials to be joined. For example, for aluminum/copper joints, hot working alloy steel is generally used, while for harder metals such as titanium/aluminum joints, tungsten carbide is common.
Welding Parameters.
In DFSW, mechanical properties mainly include tensile strength, hardness, yield strength, elongation. Selecting optimum welding parameters results in achieving proper mechanical properties of the joint. Tool rotational speed (rpm), tool traverse speed (mm/min), tool tilt angle (degree), tool offset (mm), tool penetration (mm), and tool geometry are most important welding parameters in DFSW. The tool center is typically placed in the centerline of the joint for similar joints such as aluminum/aluminium or copper/copper joints; in contrast, it is shifted towards the softer materials in DFSW called "tool offset". It is a significant factor to achieve a joint possessing smaller welding defect and higher mechanical properties. Generally, harder and softer materials are placed in Advancing Side (AS) and Retreating Side (RT) respectively. Regardless of the tool geometry, which plays a critical role on final mechanical and metallurgical properties of the weldment, the effect of the tool rotational speed and tool offset are taken into account as the most important welding parameters during DFSW.
Heat Generation.
A non-consumable rotating tool is plunged into the interface of parent materials. Frictional heat arisen from the tool shoulder throughout welding plasticizes the parent materials leading to local plastic deformation of the parent materials. Localized heat generated by the tool results from following process. At the initial stage, it is primarily arisen from frictional heat between the plunged pin and parent materials. Afterwards, it is mainly produced by the frictional heat between the shoulder surface and the top-surface of base metals once the shoulder touched the top-surface. Subsequently, the softened materials are stirred together by the rotating pin resulting in a solid-state bond. Frigaard et al. showed that tool rotational speed and tool shoulder diameters are the main contributing factors in heat generation.
Material Flow.
The mechanism of bonding in DFSW is based on two simple concepts. First, stirred materials, a mixture flow of soft and hard metals, is forged into the interface of harder material leading to strong mechanical bond at the interface. Furthermore, a complementary metallurgical bond is formed at the interface enhancing and improving mechanical properties of the joint. Materials flow throughout DFSW depends on various parameters including welding process parameters, tool geometry, and base materials. Tool geometry is the most important factor in achieving appropriate material flow.
Defects.
Occurrence of welding defects in DFSW are quite common. Welding defects in DFSW include tunneling defect, fragment defect, crack, void, surface cavity or grooves and excessive flash formation. Amongst these, tunneling defect is the most common defect in DFSW resulting from improper material flows throughout welding. It is mainly attributed to inappropriate selection of welding parameters particularly welding speed, rotational speed, tool design and tool penetration leading to either abnormal stirring or insufficient heat input. Formation of coarse fragments of harder materials within the matrix of softer materials is another typical defect observed only in DFSW. Generally, during DFSW, the paste materials behave like a metal matrix composite such that harder and softer materials act as the matrix and the reinforcement respectively. In fact, it is quite important to keep the harder material in relatively small size in order to achieve the best flow of materials. Therefore, any factors that cause formation of large piece of harder material lead to appearance of fragment defects. Tool offset and tool pin design were taken into account as the most significant contributing factors in formation of fragment defect in DFSW. They were accounted for disturbing the flow of material resulting from the formation of large pieces of harder material within the matrix of softer material due to the fact that it is quite difficult to stir and mix paste materials when one of them is not relatively fine. In addition, fragment defects usually accompany with other defects such as voids and cracks.
Typical Characteristics.
DFSW shows various characteristics in terms of hardness distribution, tensile strength, microstructure, formation of intermetallic compounds as well as formation of a composite structure within the stir zone. The majority of the dissimilar joints fabricated by FSW demonstrate similar results.
Hardness.
Since the base materials have different mechanical properties, the hardness distribution is not homogeneous which can be attributed to two different reasons. First, different mechanical properties of base materials including the hardness causes inhomogeneity in the weldments. Second, different microstructure and grain size of the welding zones including stir zone, TMAZ, and HAZ result in various hardness. Moreover, the hardness in the nugget zone or stir zone is very inhomogenous because of the formation of onion ring (composite structure ) and IMCs. As a result, dissimilar joints shows inhomogenous distribution in the nugget zone or stir zone.
Microstructure.
Four different welding zones including Stir Zone (SZ) or nugget zone, Thermo-Mechanical Affected Zone (TMAZ), Heat affected zone (HAZ) and Base Metals (BM) are typically observed in dissimilar joints made by FSW. Microstructure of the weldment demonstrates a remarkable grain refinement in the stir zone along with elongation of the grains in the TMAZ. Intensive plastic deformation risen up by tool action, rotational and traverse movements, account for the notable grain refinement in the stir zone. Moreover, HAZ presents relatively coarser grain that can be attributed to lower cooling rate in comparison with other welding areas. Some phenomena are typical in dissimilar friction stir welding including formation of Intermetallic Compounds (IMCs) and appearance of a Composite-like Structure (CS) appeared in various patterns specifically onion rings shown in below figure. IMCs and CS enhance mechanical behavior of the joints depending their conditions such as the thickness of IMCs as well as distribution pattern of composite-like structure. Proper selection of welding parameters optimizes formation of IMCs and CS resulting in the highest mechanical properties. As pointed out before, rotational speed, welding speed, and tool offset along with tool pin are the most important factors affecting on mechanical and metallurgical properties during DFSW. Unlike conventional fusion welding methods that are accompanied with substantially thick interfacial IMCs, forming an interfacial metallurgical bond during DFSW is essential to achieve a sound joint. However, it should be kept at optimum condition to enhance and improve mechanical properties i.e. it should be thin, uniform and contentious.
IMCs.
IMCs are another typical phenomenon in DFSW. There existed some criteria for IMCs in order to achieve a sound joint including thickness, uniformity and continuity. The most common type of IMCs appeared in aluminum/copper joint are Al4Cu9, Al2Cu3, Al2Cu. Interface and surrounding edge of the particles dispersed in the nugget zone are two main places IMCs formed. Likewise, depending the size of the particles of harder material which dispersed in the matrix of softer material, coarse particles partially transform to IMCs mostly around the outer edge of the particles, while fine particles completely transform to IMCs. It is worth noting that the average thickness of IMCs are less than 2 micrometer. Therefore, those particles that are below than 2 micrometer are completely transform to IMCs resulting in enhancing mechanical properties of the nugget zone.
Tensile Strength.
Another important characteristic in DFSW is the final tensile strength. The majority of dissimilar weldments presented similar trend in tensile strength. There are two different materials in DFSW. One is softer than the other. For example, in aluminum to copper joint, aluminum is softer than copper. What would be the tensile strength of the joint? Is it more than both? Is it less than both? What is the requirement for the sound joint? The answer is that tensile strength of the joints in DFSW are a fraction of the tensile strength of the softer material. Therefore, the final tensile strength of the weldments are usually less than tensile strength of both materials, however, in order to be acceptable in the industry, it is usually more than 70 percent of the tensile strength of the softer material. Fracture behavior of the tensile specimens shows that majority of the joints failed at the interface along with a brittle fracture. It can be attributed to IMCs developed at the interface. Although, it could successfully improve tensile strength, but the specimens showed brittle fracture which is one of the existing challenge in dissimilar joints fabricated by FSW.
Formation of composite structure.
Due to the fact that there are two different materials in DFSW; formation of a composite structure within the nugget zone is inevitable. Typically, it appears in the forming of onion ring in the nugget zone or stir zone of the softer matrix as shown in below figure. That is, fine particle of the material in the advancing side (harder material) disperse throughout the stir zone of the retreating material (Softer material). That is the main reason regarding the inhomogeneous hardness distribution in the stir zone.
Challenge.
FSW can be efficient method to be used in order to join dissimilar materials and the outcome in terms of tensile strength, shear strength, and hardness distribution are promising. However, most of the joints fractured at interface. Moreover, even those that have been ruptured in the base metals showed brittle behavior i.e. low elongation which can be attributed to formation of IMCs. There must a balance between tensile strength and ductility of the weldments in order to safely use dissimilar weldments in industrial applications. In other words, proper ductility and toughness are required for some industrial applications since they should possess proper resistivity against impact and shock loading. The majority of the fabricated weldments are not sufficiently strong to be used for such applications. Therefore, it is worthwhile to focus current and future works on improving toughness of the weldments along with keeping tensile strength in a proper value.