Machine shop

A machine shop or engineering workshop is a room, building, or company where machining, a form of subtractive manufacturing, is done. In a machine shop, machinists use machine tools and cutting tools to make parts, usually of metal or plastic (but sometimes of other materials such as glass or wood). A machine shop can be a small business (such as a job shop) or a portion of a factory, whether a toolroom or a production area for manufacturing. The building construction and the layout of the place and equipment vary, and are specific to the shop; for instance, the flooring in one shop may be concrete, or even compacted dirt, and another shop may have asphalt floors. A shop may be air-conditioned or not; but in other shops it may be necessary to maintain a controlled climate. Each shop has its own tools and machinery which differ from other shops in quantity, capability and focus of expertise.
The parts produced can be the end product of the factory, to be sold to customers in the machine industry, the car industry, the aircraft industry, or others. It may encompass the frequent machining of customized components. In other cases, companies in those fields have their own machine shops.
The production can consist of cutting, shaping, drilling, finishing, and other processes, frequently those related to metalworking. The machine tools typically include metal lathes, milling machines, machining centers, multitasking machines, drill presses, or grinding machines, many controlled with computer numerical control (CNC). Other processes, such as heat treating, electroplating, or painting of the parts before or after machining, are often done in a separate facility.
A machine shop can contain some raw materials (such as bar stock for machining) and an inventory of finished parts. These items are often stored in a warehouse. The control and traceability of the materials usually depend on the company's management and the industries that are served, standard certification of the establishment, and stewardship.
A machine shop can be a capital intensive business, because the purchase of equipment can require large investments. A machine shop can also be labour-intensive, especially if it is specialized in repairing machinery on a job production basis, but production machining (both batch production and mass production) is much more automated than it was before the development of CNC, programmable logic control (PLC), microcomputers, and robotics. It no longer requires masses of workers, although the jobs that remain tend to require high talent and skill. Training and experience in a machine shop can both be scarce and valuable.
Methodology, such as the practice of 5S, the level of compliance over safety practices and the use of personal protective equipment by the personnel, as well as the frequency of maintenance to the machines and how stringent housekeeping is performed in a shop, may vary widely from one shop to another.
History.
Until the 19th century.
The first machine shops started to appear in the 19th century when the Industrial Revolution was already long underway. Before the industrial revolution parts and tools were produced in workshops in local villages and cities on small-scale often for a local market. The first machinery that made possible the Industrial Revolution were also developed in similar workshops.
The production machines in the first factories were built on site, where every part was still individually made to fit. After some time those factories started their own workshops, where parts of the existing machinery were repaired or modified. In those days textiles were the dominant industry, and these industries started to further develop their own machine tools.
19th century.
Further development early in the 19th century in England, Germany and Scotland of machine tools and cheaper methods for the production of steel, such as the Bessemer steel, triggered the Second Industrial Revolution, which culminated in early factory electrification, mass production and the production line. The machine shop emerged as Burghardt called, a "place in which metal parts are cut to the size required and put together to form mechanical units or machines, the machines so made to be used directly or indirectly in the production of the necessities and luxuries of civilization."
The rise of machine shops and their specific manufacturing and organizational problems triggered the early job shop management pioneers, whose theories became known as scientific management. One of the earliest publications in this field was Horace Lucian Arnold, who in 1896 wrote a first series of articles about "Modern Machine-Shop Economics." This work stretched out from production technology, production methods and factory lay out to time studies, production planning, and machine shop management. A series of publications on these topics would follow. In 1899 Joshua Rose published the book "Modern machine-shop practice," about the operation, construction, and principles of shop machinery, steam engines, and electrical machinery.
20th century.
In 1903 the "Cyclopedia of Modern Shop Practice" was published with Howard Monroe Raymond as Editor-in-Chief, and in the same year Frederick Winslow Taylor published his "Shop management; a paper read before the American society of mechanical engineers. New York." Taylor had started his workmanship as a machine-shop laborer at Midvale Steel Works in 1878, and worked his way up to machine shop foreman, research director, and finally chief engineer of the works. As an independent consulting engineer one of his first major assignments was in 1898 at Bethlehem Steel was to solve an expensive machine-shop capacity problem.
In 1906 Oscar E. Perrigo published the popular book "Modern machine shop," construction the equipment and management of machine shops. The first part of "Modern machine shop," Perrigo (1906) focussed on the physical construction of the building and presented a model machine shop. With this model machine shop, Perrigo explored the way the space in factories could be organized. This was not uncommon in his days. Many industrial engineers, like Alexander Hamilton Church, J. Slater Lewis, Hugo Diemer etc., published plans for some new industrial complex.
These works among others cumulated in the scientific management movement on which Taylor in 1911 wrote his famous "The Principles of Scientific Management," a seminal text of modern organization and decision theory, with a significant part dedicated to the organization of machine shops. The introduction of new cutting materials as high-speed steel, and better organization of the production by implementing new scientific management methods such as planning boards (see image), significantly improved machine shop productivity and efficiency of machine shops. In the course of the 20th century, these further increased with the further development of technology.
In the early 20th century, the power for the machine tools was still supplied by a mechanical belt, which was powered by a central steam engine. In the course of the 20th-century electric motors took over the power supply of the machine tools.
As materials and chemical substances, including cutting oil, become more sophisticated, the awareness of the impact on the environment slowly grew. In parallel to the acknowledgment of the ever-present reality of accidents and potential occupational injury, the sorting of scrap materials for recycling and the disposal of refuse evolved in an area related to the environment, safety, and health. In regulated machine shops this would turn into a constant practice supported by what would be a discipline known as EHS (for environment, health, and safety), or of a similar name, such as HQSE that would include quality assurance.
In the second part of the 20th century, automation started with numerical control (NC) automation, and computer numerical control (CNC).
Digital instruments for quality control and inspection become widely available, and the utilization of lasers for precision measurements became more common for the larger shops that can afford the equipment.
Further integration of information technology into machine tools lead to the beginning of computer-integrated manufacturing. Production design and production became integrated into CAD/CAM, and production control became integrated in enterprise resource planning.
21st century.
In the late of the 20th century, the introduction of industrial robots further increased factory automation. Typical applications of robots include welding, painting, assembly, pick and place (such as packaging, palletizing and SMT), product inspection, and testing. As a result of this introduction the machine shop also "has been modernized to the extent that robotics and electronic controls have been introduced into the operation and control of machines. For small machine shops, though, having robots is more of an exception.
Machine shop topics.
Machines.
A machine is a tool containing one or more parts that uses energy to perform an intended action. Machines are usually powered by mechanical, chemical, thermal, or electrical means, and are often motorized. Historically, a power tool also required moving parts to classify as a machine. However, the advent of electronics has led to the development of power tools without moving parts that are considered machines.
Machining.
Machining is any of the various processes in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process. The many processes that have this common theme, controlled material removal, are today collectively known as subtractive manufacturing, in distinction from processes of controlled material addition, which are known as additive manufacturing. Exactly what the "controlled" part of the definition implies can vary, but it almost always implies the use of machine tools (in addition to just power tools and hand tools).
Though not all machine shops may have a CNC milling center, commonly, they may have access to a manual milling machine.
Machine tools.
A machine tool is a machine for shaping or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformation. Machine tools employ some sort of tool that does the cutting or shaping. All machine tools use some means of constraining the workpiece and provide a guided movement of the parts of the machine. Thus the relative movement between the workpiece and the cutting tool is controlled or constrained by the machine to at least some extent, rather than being entirely "offhand" or "freehand".
Cutting tools.
Professional management of the inventory of cutting tools occurs mainly in larger operations. Smaller machine shops may have a more limited assortment of endmills, keyseat cutters, inserts, and other cutting tools. The choice in the sophistication of the design of the cutting tool, including material and finish, commonly depends on the job and the price of the cutting tool. In some instances, the cost of custom-made tools could be prohibitive for a small shop.
Depending on the industry and demands of the job, a cutting tool may only be used on a certain type of material, that is, a cutting tool may not contact another workpiece made of different chemical composition.
Not all machine shops are equipped with a mill and not all machine shops are aimed to do milling work.
Housekeeping.
Some machine shops are better organized than others, and some places are kept cleaner than other establishments. In some instances, the shop is swept minutes before the end of every shift, and in other cases, there's no schedule or routine, or the cycle for sweeping and cleaning is more relaxed.
When it comes to machines, in some places the care and maintenance of the equipment are paramount, and the swarf (commonly known as chips) produced after parts have been machined, are removed daily, and then the machine is air-blown and wiped clean; while in other machine shops, the chips are left in the machines until is an absolute necessity to remove them; the second instance is not advisable.
Recycling.
The remanent or residue of materials used, such as aluminum, steel, and oil, among others, can be gathered and recycled, and commonly, it may be sold. However, not all machine shops practice recycling, and not all have personnel dedicated to enforcing the habit of separating and keeping materials separated. In larger and organized operations, such responsibility may be delegated to the Health, Safety, Environment, and Quality (HSEQ) department.
Inspection.
Quality assurance, quality control and inspection, are terms commonly used interchangeably. The accuracy and precision to be attained depends on several determining factors. Since not all machines have the same level of reliability and capability to execute predictable finished results within certain tolerances, nor all manufacturing processes achieve the same range of exactness, the machine shop is then limited to its own dependability in delivering the desire outcomes. Subsequently, subject to the rigor declared by the customer, the machine shop may be required to undergo a verification and validation even prior to the issuance and acknowledgment of an order.
The machine shop may have a specific area established for measuring and inspecting the parts in order to confirm compliance, while other shops only rely on the inspections performed by the machinists and fabricators. For instance, in some shops, a granite, calibrated surface plate may be shared by different departments, and in other shops, the lathes, the mills, etc, may have their own, or may not have one at all.
Calibration.
The standards followed, the industry served, quality control, and mainly the type of practices in the machine shop, will denote the utilization of precision inspection instruments, and the accuracy of metrology employed. This means that not all machine shops implement a periodic interval for calibrating measuring devices. Not all machine shops have the same type of measuring instruments, though it is common to find micrometers, Vernier calipers, granite surface plates, among others.
The frequency and precision for calibrating metrology instruments may vary and it may require hiring the services of a specialized third-party. Also, in some instances, maintaining all instruments existent in the shop calibrated may be a requirement to not fall out of compliance.
Layout.
The location and orientation of the machines are important. Preferably, some prior thought has been given in the positioning of the equipment; likely not as meticulously as in a plant layout study, the closeness of the machines, the types of machines, were the raw material are received and kept, as well as other factors, including ventilation, are taken in account to establish the initial layout of the machine shop. A routing diagram and daily operations may dictate the need to rearrange.
Profitability is commonly a driving consideration in regards to maximizing production, and thus aligning the machines in an effective manner; however, other critical factors must be considered, such as the preventive maintenance of the equipment and safety in the workplace. For instance, allowing room for a technician to maneuver behind the machining center to inspect connections, and not placing the machine where it would block the emergency exit.
Storage rooms and tool cribs.
Some shops have cages or rooms dedicated to keeping certain tools or supplies; for instance, a room may be dedicated to only welding supplies, gas tanks, etcetera; or where janitorial supplies or other consumables such as grinding disks are stored. Depending on the size of the operation, management, and controls, these areas may be restricted and locked, or these could be manned by an employee, as by a tool crib attendant; in other instances, the storage rooms or cages are accessible to all personnel. Not all shops have a tool crib or storage room(s) though, and in many cases, a large cabinet suffices.
Hand tools.
Also, the way hand tools are stored and are made available to the fabricator or operators depends on how the shop functions or is managed. In many cases, common hand tools are visible in the work area and at reach for anyone. In many cases, the workers do not need to provide their own tools since the daily tools are available and provided, but in many other cases, the workers bring their own tools and toolboxes to their workplace
Safety.
Safety is a consideration that needs to be observed and enforced daily and constantly; however, a shop may vary from other shops in strictness and thoroughness when it comes to the actual practice, policies implemented and overall seriousness ascertained by the personnel and management. In an effort to standardize some common guidelines, in the United States, the Occupational Safety and Health Administration (OSHA) issues didactic material and enforces precautions with the goal of preventing accidents.
In a machine shop usually, there are numerous practices that are known in relation to working safely with machines. Some of the common practices include:
Safety precautions in a machine shop are aimed to avoid injuries and tragedies, for example, to eliminate the possibility of a worker being fatally harmed by being entangled in a lathe.
Many machines have safety measurements as built-in parts of their design; for example, an operator must press two buttons which are out of the way for a press or punch to function, and thus not pinch the operator's hands.


Crash box (stagecraft)

A crash box is a device which reproduces a crash or collision sound effect. Commonly used in theatre, they consist of a large metal or wood crate in which glassware, china crockery, wood blocks or other delicate objects are placed. The items may or may not be broken. Crash boxes can usually be used multiple times, until the objects inside of them become so broken that they no longer give the desired effect. They can then be reloaded with more breakable objects and reused. Crash boxes are used to recreate the sounds of a crash, collision or glass breakage in theatre. To recreate the sound effects, crash boxes are dropped from a height backstage. They can also be shaken to create a gentler sound effect. A crash box is generally preferred to a recorded sound effect because it is perceived as more realistic.


Product layout

In manufacturing engineering, a product layout refers to a production system where the work stations and equipment are located along the line of production, as with assembly lines.
Usually, work units are moved along line (not necessarily a geometric line, but a set of interconnected work stations) by a conveyor. Work is done in small amounts at each of the work stations on the line. To use the product layout, the total work to be performed must be dividable into small tasks that can be assigned to each of the workstations.
Because the work stations each do small amounts of work, the stations utilize specific techniques and equipment tailored to the individual job they are assigned. This can lead to a higher rate of production.


Manufacturing cost

Manufacturing cost is the sum of costs of all resources consumed in the process of making a product. The manufacturing cost is classified into three categories: direct materials cost, direct labor cost and manufacturing overhead. It is a factor in total delivery cost.
Direct materials cost.
Direct materials are the raw materials that become a part of the finished product. Manufacturing adds value to raw materials by applying a chain of operations to maintain a deliverable product. There are many operations that can be applied to raw materials such as welding, cutting and painting. It is important to differentiate between direct materials and indirect materials.
Direct labour cost.
The direct labour cost is the cost of workers who can be easily identified with the unit of production. Types of labour who are considered to be part of the direct labour cost are the assembly workers on an assembly line.
Manufacturing overhead.
Manufacturing overhead is any manufacturing cost that is neither direct materials cost nor direct labour cost. Manufacturing overhead includes all charges that provide support to manufacturing.


Skid mount

A Skid mount is a popular method of distributing and storing machinery and usually-stationary equipment for the military and industry on its own or with other units as part of a modular system (modular process skid). The machinery at point of manufacture is permanently mounted in a frame or onto rails or a metal Pallet. The equipment can then be easily secured and transported and used as a unit. A unit such as a fire-fighting Skid unit may also be temporarily placed onto a vehicle to equip it for a task. They often have standard sized holes (called "pockets") for a forklift truck to slide into it to lift it safely.
It could be thought of as a permanently attached Pallet (also known as a skid).
As well as making it more transportable, it adds stability when static.
To facilitate factory floor efficiency, machinery such as laser welders, plastic injection molding units, lathes and sewing machines are often skid mounted for easy placement according to work flow needs.


Optical lens design

Optical lens design is the process of designing a lens to meet a set of performance requirements and constraints, including cost and manufacturing limitations. Parameters include surface profile types (spherical, aspheric, holographic, diffractive, etc.), as well as radius of curvature, distance to the next surface, material type and optionally tilt and decenter. The process is computationally intensive, using ray tracing or other techniques to model how the lens affects light that passes through it.
Design requirements.
Performance requirements can include:
Design constraints can include realistic lens element center and edge thicknesses, minimum and maximum air-spaces between lenses, maximum constraints on entrance and exit angles, physically realizable glass index of refraction and dispersion properties.
Manufacturing costs and delivery schedules are also a major part of optical design. The price of an optical glass blank of given dimensions can vary by a factor of fifty or more, depending on the size, glass type, index homogeneity quality, and availability, with BK7 usually being the cheapest. Costs for larger and/or thicker optical blanks of a given material, above 100–150 mm, usually increase faster than the physical volume due to increased blank annealing time required to achieve acceptable index homogeneity and internal stress birefringence levels throughout the blank volume. Availability of glass blanks is driven by how frequently a particular glass type is made by a given manufacturer, and can seriously affect manufacturing cost and schedule.
Process.
Lenses can first be designed using paraxial theory to position images and pupils, then real surfaces inserted and optimized. Paraxial theory can be skipped in simpler cases and the lens directly optimized using real surfaces. Lenses are first designed using average index of refraction and dispersion (see Abbe number) properties published in the glass manufacturer's catalog and through glass model calculations. However, the properties of the real glass blanks will vary from this ideal; index of refraction values can vary by as much as 0.0003 or more from catalog values, and dispersion can vary slightly. These changes in index and dispersion can sometimes be enough to affect the lens focus location and imaging performance in highly corrected systems.
The lens blank manufacturing process is as follows:
The glass blank pedigree, or "melt data", can be determined for a given glass batch by making small precision prisms from various locations in the batch and measuring their index of refraction on a spectrometer, typically at five or more wavelengths. Lens design programs have curve fitting routines that can fit the melt data to a selected dispersion curve, from which the index of refraction at any wavelength within the fitted wavelength range can be calculated. A re-optimization, or "melt re-comp", can then be performed on the lens design using measured index of refraction data where available. When manufactured, the resulting lens performance will more closely match the desired requirements than if average glass catalog values for index of refraction were assumed.
Delivery schedules are impacted by glass and mirror blank availability and lead times to acquire, the amount of tooling a shop must fabricate prior to starting on a project, the manufacturing tolerances on the parts (tighter tolerances mean longer fab times), the complexity of any optical coatings that must be applied to the finished parts, further complexities in mounting or bonding lens elements into cells and in the overall lens system assembly, and any post-assembly alignment and quality control testing and tooling required. Tooling costs and delivery schedules can be reduced by using existing tooling at any given shop wherever possible, and by maximizing manufacturing tolerances to the extent possible.
Lens optimization.
A simple two-element air-spaced lens has nine variables (four radii of curvature, two thicknesses, one airspace thickness, and two glass types). A multi-configuration lens corrected over a wide spectral band and field of view over a range of focal lengths and over a realistic temperature range can have a complex design volume having over one hundred dimensions.
Lens optimization techniques that can navigate this multi-dimensional space and proceed to local minima have been studied since the 1940s, beginning with early work by James G. Baker, and later by Feder, Wynne, Glatzel, Grey and others. Prior to the development of digital computers, lens optimization was a hand-calculation task using trigonometric and logarithmic tables to plot 2-D cuts through the multi-dimensional space. Computerized ray tracing allows the performance of a lens to be modelled quickly, so that the design space can be searched rapidly. This allows design concepts to be rapidly refined. Popular optical design software includes Zemax's OpticStudio, Synopsys's Code V, and Lambda Research's OSLO. In most cases the designer must first choose a viable design for the optical system, and then numerical modelling is used to refine it. The designer ensures that designs optimized by the computer meet all requirements, and makes adjustments or restarts the process when they do not.


Factory automation infrastructure

Factory automation infrastructure describes the process of incorporating automation into the manufacturing environment and processing of input goods into final products.
The manufacturing environment is defined by its ability to manufacture and/or assemble goods by machines, integrated assembly lines, and robotic arms. Automated environments are also defined by their coordination with (and usually their systematic integration with) the required automatic equipment to form a complete system.
Factory automation intends to decrease risks associated with laborious and dangerous work faced by human workers. This system is essentially a solution for the automation and manufacturing of a particular production process of an intended output and/or final/end product.
Automation.
Automation has produced sophisticated parts with similar or higher output qualities with minor quality fluctuation. It also can help cut overall manufacturing costs and create safer working environments for workers.
The use of automation in manufacturing started by using technologies such as pneumatic and hydraulic systems in applications where their mechanical advantages could be used to raise output quality and efficiency in production. Complex and highly integrated systems have since evolved, composed of many different technologies and innovative procedures controlled under High Language programming environments with sophisticated operation drivers. These drivers often are running languages that support 6, 7, and 8-axis controls for sophisticated robotics.
Robotic arm.
A robotic arm is a type of mechanical arm, usually programmable, with functions similar to a human arm; the arm may be the total of the mechanism or may be part of a more complex robot. The links of such a manipulator are connected by joints allowing either rotational motion (such as in an articulated robot) or transnational (linear) displacement. The links of the manipulator can be considered to form a kinematic chain. The terminus of the kinematic chain of the manipulator is called the end effector and is analogous to the human hand.
Advantages and disadvantages.
The main advantages of automation are:
The following methods are often employed to improve productivity, quality, or robustness.
The main disadvantages of automation are:
External links.
kinematic chain.


Profile (engineering)

In standardization, a profile is a subset internal to a specification. Aspects of a complex technical specification may necessarily have more than one interpretation, and there are probably many optional features. These aspects constitute a profile of the standard. Two implementations engineered from the same description may not interoperate due to having a different profile of the standard. Vendors can even ignore features that they view as unimportant, yet prevail in the long run.
The use of profiles in these ways can force one interpretation, or create de facto standards from official standards. Engineers can design or procure by using a profile to ensure interoperability. For example, the International Standard Profile, ISP, is used by the ISO in their ISO ISP series of standards; in the context of OSI networking, Britain uses the UK-GOSIP profile and the US uses US-GOSIP; there are also various mobile profiles adopted by the W3C for web standards. In particular, implementations of standards on mobile devices often have significant limitations compared to their traditional desktop implementations, even if the standard which governs both permits such limitations.
In structural engineering a profile means a hot rolled structural steel shape like an -beam.
In civil engineering, a profile consists of a plotted line which indicates grades and distances (and typically depths of cut and/or elevations of fill) for excavation and grading work. Constructors of roadways, railways (and similar works) normally chart the profile along the centerline. A profile can also indicate the vertical slope(s) (changes in elevation) in a pipeline or similar structure. Civil engineers always depict profile as a side (cross section) view (as opposed to an overhead (plan) view).
Material fabrication.
In fabricating, a profile consists of the more-or-less complex outline of a shape to be cut in a sheet of material such as laminated plastic, aluminium alloy or steel plate. In modern practice, a drawing office determines the shape and dimensions required to fit the sheet into a larger work and feeds directions to a computer controlling a profile cutter. This then cuts the shape from a standard-sized sheet. The cutting head may use a rotating cutter like that of a spindle router or (in the case of steel plate) a torch which burns oxy-acetylene or other oxy-gas.


Printing registration

In color printing, print registration is the layering of printed patterns to form a multicolor pattern. Registration error is the "position misalignment in the overlapped patterns." Machine components such as the print cylinder, doctor blade assembly, printing plates, stress/friction and more, affect the registration of the machine. Inconsistencies among these components can cause the printing press to fall out of registration; that is when press operators will begin to see defects in their print. There are many different ways to achieve proper registration, many of which employ the alignment of registration marks (pictured right). Many press manufacturers have installed automatic register systems to assist the operator in getting the print back into proper alignment.
Purpose.
When printing an image or a package of some sort that has more than one color, it is necessary to print each color separately and ensure each color overlaps the others precisely. If this is not done, the finished image will look fuzzy, blurred or "out of register" (see image to right). If one or more print units, plate or other print component is out of registration, the result can be printed colors in the wrong areas, overprint or white space. With proper registration, there will be no white space, out of margin colors, or confusing overlap of images in the print. To help line the colors up correctly, a registration system is necessary.
Remedies.
Trapping.
A remedy for slight misregistration is trapping. Trapping is a method of adjusting areas where two distinct, adjacent colors meet so that press misregistration won't cause white spaces. Where two colours abut, the lighter colour is slightly expanded into the darker to create an overlap. This yields a darker outline, which is considered less objectionable than a white gap. A major exception to this is the case when opaque (colors that completely obscure colors printed beneath them) spot colors are used. Other colors, regardless of their relative luminance, are always trapped to (spread under) these spot colors. If several of these spot colors are used (a common practice in the packaging market), the order of printing layers rather than luminance is the decisive element: the first color to be printed is spread under the next color. The trap width is dictated by the maximum amount of misregistration of the entire workflow up to the press.
Overprinting.
Black ink is set to "overprint" colors in the background. The difference is not visible since the lighter color is spread underneath the—almost—opaque black.
Types of (stone) lithography registration.
There are many different styles of registration for many different types of printing. These deal with stone lithography, as used in fine arts printmaking.
T-bar.
This method, using small measured registration marks on both the stone and the paper, is very accurate and simple to do. The printer measures the exact size of the paper and the desired margins. Then marks are made at both ends of the sheet of paper, and corresponding marks (usually in the shape of a "T") are made on the stone. Then the printer matches the marks on the paper to those on the stone. This way many runs of different colors can be pulled exactly in line with one another, each of them measured from the same system of marks.
Pin-hole.
This method involves laying the paper on the un-inked surface, and making a pin-hole through both the bottom and top of the paper, being careful to make a mark in the stone's surface. Then the locations of the holes are transferred to each sheet of paper to be printed. When printing, one should place pins in each hole of a sheet of paper, and lower it onto the inked stone, placing each pin in its respective hole in the stone. This method can ruin paper by creating holes and if the holes get too large, they lose their function as registration devices.
Eyeballing.
This method relies solely on hand–eye coordination. Eyeballing can be found in other industries as well. The printer places the paper over the stone-image, measuring and judging registration by eye. This is not very consistent, depending on the person.


Disco Corporation

 is a Japanese precision tools maker, especially for the semiconductor production industry.
The company makes dicing saws and laser saws to cut semiconductor silicon wafers and other materials; grinders to process silicon and compound semiconductor wafers to ultra-thin levels; polishing machines to remove the grinding damage layer from the wafer back-side and to increase chip strength.
History.
The company was founded as Daiichi-Seitosho in May 1937, as an industrial abrasive wheel manufacturer.
After World War II Japan faced a construction boom which also helped DISCO to boost its sales. The company's grinder discs were in high demand from utility companies, which needed them to manufacture watt-meters.
In December 1968 the company developed and released an ultra-thin resinoid cutting wheel, "Microncut". The wheel contained diamond powder and as a result it was capable of making sharp, precision cuts as demanded in the semiconductor manufacturing process. There were no cutting machines available in the market on which ultra-thin precision wheels could be mounted and run, DISCO decided to develop its own machine in 1975. The cutting machine, DAD-2h, received instant recognition from semiconductor companies, including Texas Instruments.
The company adopted the name of DISCO Corporation in May 1977, was listed with the Japan Securities Dealers' Association in October 1989, and entered the First Section of the Tokyo Stock Exchange in December 1999.


1996–97 UEFA Cup

The 1996–97 UEFA Cup was the 26th season of the UEFA Cup, the third-tier club football competition organised by the Union of European Football Associations (UEFA). It was won by German side Schalke 04, who beat Internazionale of Italy on penalties after the two-legged final finished 1–1 on aggregate. Defending champions Bayern Munich were eliminated in the first round by Valencia.
This was the last year in which the UEFA Cup final was played in a two-legged, home-and-away format. From 1998, the final was played as a single match at a neutral venue.
Format.
According to 1995 UEFA ranking, Bulgaria ceded a slot to Norway.
The access list was finally increased to 117 clubs:
A second qualifying round was consequently added for the first time in the history of the European competitions.
Teams.
The labels in the parentheses show how each team qualified for the place of its starting round:
Preliminary round.
Second leg.
"Dinamo Tbilisi won 6–2 on aggregate."
"Dinamo-93 Minsk won 4–2 on aggregate."
"Croatia Zagreb won 10–2 on aggregate."
"Sliema Wanderers won 4–3 on aggregate."
"FC Jazz won 4–1 on aggregate."
"Vardar won 3–1 on aggregate."
"Anorthosis Famagusta won 6–2 on aggregate."
"Vojvodina won 5–1 on aggregate."
"HJK won 6–5 on aggregate."
"Lantana Tallinn won 2–1 on aggregate."
"1–1 on aggregate; Dinamo Minsk won on away goals."
"Beitar Jerusalem won 8–2 on aggregate."
"Legia Warsaw won 7–2 on aggregate."
"Slavia Sofia won 5–4 on aggregate."
"ÍA won 2–1 on aggregate."
"Lokomotiv Sofia won 7–2 on aggregate."
"Skonto won 7–1 on aggregate."
"Hajduk Split won 6–1 on aggregate."
"APOEL won 9–3 on aggregate."
"Barry Town won 2–1 on aggregate."
"Žalgiris Vilnius won 3–2 on aggregate."
"Košice won 6–2 on aggregate."
"Haka won 3–2 on aggregate."
"Mura won 2–0 on aggregate."
"Hutnik Kraków won 11–2 on aggregate."
"Partizan won 4–1 on aggregate."
"Slovan Bratislava won 5–3 on aggregate."
Qualifying round.
Second leg.
"Dynamo Moscow won 4–2 on aggregate."
"Rapid București won 2–0 on aggregate."
"Neuchâtel Xamax won 6–1 on aggregate."
"Halmstad won 1–0 on aggregate."
"Grazer AK won 7–1 on aggregate."
"Legia Warsaw won 4–1 on aggregate."
"APOEL won 3–1 on aggregate."
"Helsingborg won 4–1 on aggregate."
"CSKA Moscow won 6–1 on aggregate."
"Odense won 9–1 on aggregate."
"Aberdeen won 5–4 on aggregate."
"4–4 on aggregate; Barry Town won 4–2 on penalties."
"Hutnik Kraków won 3–2 on aggregate."
"Trabzonspor won 5–3 on aggregate."
"Național București won 1–0 on aggregate."
"Aarau won 4–2 on aggregate."
"3–3 on aggregate; Spartak Moscow won on away goals."
"Tirol Innsbruck won 5–2 on aggregate."
"Torpedo Moscow won 2–1 on aggregate."
"Bodø/Glimt won 7–2 on aggregate."
"Lyngby won 2–0 on aggregate."
"Celtic won 1–0 on aggregate."
"Chornomorets Odesa won 4–2 on aggregate."
"Dinamo Tbilisi won 2–1 on aggregate."
"Malmö won 4–1 on aggregate."
"Beşiktaş won 3–2 on aggregate."
First round.
Second leg.
"Feyenoord won 2–1 on aggregate."
"Ferencváros won 5–3 on aggregate."
"Slavia Prague won 5–2 on aggregate."
"Beşiktaş won 3–0 on aggregate."
"Hamburg won 4–0 on aggregate."
"Național București won 2–0 on aggregate."
"Metz won 1–0 on aggregate."
"Brøndby won 7–0 on aggregate."
"Club Brugge won 3–1 on aggregate."
"4–4 on aggregate; Boavista won on away goals."
"Valencia won 3–1 on aggregate."
"Roma won 6–1 on aggregate."
"Neuchâtel Xamax won 2–1 on aggregate."
"Schalke 04 won 5–2 on aggregate."
"Lazio won 2–1 on aggregate."
"Internazionale won 4–1 on aggregate."
"Aberdeen won 6–4 on aggregate."
"Sporting CP won 2–1 on aggregate."
"Trabzonspor won 5–2 on aggregate."
"Espanyol won 3–2 on aggregate."
"1–1 on aggregate; Helsingborg won on away goals."
"3–3 on aggregate; Grazer AK won on away goals."
"Newcastle United won 5–2 on aggregate."
"Anderlecht won 5–2 on aggregate."
"Vitória Guimarães won 3–2 on aggregate."
"Dinamo Tbilisi won 2–1 on aggregate."
"Tenerife won 4–3 on aggregate."
"Borussia Mönchengladbach won 6–4 on aggregate."
"AS Monaco won 4–1 on aggregate."
"Spartak Moscow won 5–3 on aggregate."
"4–4 on aggregate; Legia Warsaw won on away goals."
"Karlsruhe won 4–2 on aggregate."
Second round.
Second leg.
"Boavista won 5–1 on aggregate."
"Newcastle United won 6–3 on aggregate."
"Club Brugge won 3–1 on aggregate."
"1–1 on aggregate; Anderlecht won on away goals."
"Metz won 3–2 on aggregate."
"Feyenoord won 3–1 on aggregate."
"Brøndby won 2–0 on aggregate."
"Valencia won 1–0 on aggregate."
"Tenerife won 5–4 on aggregate."
"1–1 on aggregate; Internazionale won 5–3 on penalties."
"Helsingborg won 3–1 on aggregate."
"Beşiktaş won 3–2 on aggregate."
"Schalke 04 won 4–3 on aggregate."
"AS Monaco won 4–3 on aggregate."
"Karlsruhe won 4–2 on aggregate."
"Hamburg won 5–2 on aggregate."
Third round.
Second leg.
"Brøndby won 6–3 on aggregate."
"Schalke 04 won 3–2 on aggregate."
"AS Monaco won 5–0 on aggregate."
"Anderlecht won 1–0 on aggregate."
"Valencia won 5–3 on aggregate."
"Newcastle United won 3–1 on aggregate."
"Internazionale won 7–1 on aggregate."
"Tenerife won 4–2 on aggregate."
Quarter-finals.
Second leg.
"Tenerife won 2–1 on aggregate."
"AS Monaco won 4–0 on aggregate."
"Internazionale won 3–2 on aggregate."
"Schalke 04 won 3–1 on aggregate."
Semi-finals.
Second leg.
"Internazionale won 3–2 on aggregate."
"Schalke 04 won 2–1 on aggregate."
Final.
Second leg.
"1–1 on aggregate; Schalke 04 won 4–1 on penalties."
Top scorers.
The top scorers from the 1996–97 UEFA Cup are as follows:


Spray forming

Spray forming, also known as spray casting, spray deposition and in-situ compaction, is a method of casting near net shape metal components with homogeneous microstructures via the deposition of semi-solid sprayed droplets onto a shaped substrate. In spray forming an alloy is melted, normally in an induction furnace, then the molten metal is slowly poured through a conical tundish into a small-bore ceramic nozzle. The molten metal exits the furnace as a thin free-falling stream and is broken up into droplets by an annular array of gas jets, and these droplets then proceed downwards, accelerated by the gas jets to impact onto a substrate. The process is arranged such that the droplets strike the substrate whilst in the semi-solid condition, this provides sufficient liquid fraction to 'stick' the solid fraction together. Deposition continues, gradually building up a spray formed billet of metal on the substrate.
The "gas atomised spray forming" ("GASF") process typically has a molten alloy flow rate of 1–20 kg/min, although twin atomizer systems can achieve metal flow rates of up to 80 kg/min. Special steel billets of 1 tonne or more have been produced by spray forming on a commercial basis, together with Ni super-alloy ring blanks of up to 500 kg and Al alloy extrusion billets of up to 400 kg.
History.
Professor Singer at the Swansea University first developed the idea of gas atomised spray forming in the 1970s in which a high pressure gas jet impinges on a stable melt stream to cause atomisation. The resulting droplets are then collected on a target, which can be manipulated within the spray and used to form a near-dense billet of near-net shape. Spray forming has found applications in specialist industries such as: stainless steel cladding of incinerator tubes; nickel superalloy discs and rings for aerospace-engines; aluminium-titanium, aluminium-neodymium and aluminium-silver sputter targets; aluminium-silicon alloys for cylinder liners; and high speed steels. The history of spray forming is an example of how the creative contributions of many researchers were necessary over a number of years to produce the innovation of a now widely used industrial process.
Advantages.
Spray forming offers certain advantages over both conventional ingot metallurgy and more specialized techniques such as powder metallurgy. Firstly, it is a flexible process and can be used to manufacture a wide range of materials, some of which are difficult to produce by other methods, e.g. Al-5wt% Li alloys or Al-SiC, Al-Al2O3 metal matrix composites (MMCs). The atomisation of the melt stream into droplets of 10-500 μm diameter, some of which, depending on diameter, cool quickly to the solid and semi-solid state provide a large number of nucleants for the residual liquid fraction of the spray formed material on the billet top surface. The combination of rapid cooling in the spray and the generation of a large population of solid nucleants in the impacting spray leads to a fine equiaxed microstructure, typically in the range 10–100 μm, with low levels and short length scales of internal solute partitioning. These microstructural aspects offer advantages in material strength because of fine grain size, refined distribution of dispersoid and/or secondary precipitate phases, as well as tolerance to impurity 'tramp' elements. This fine structure in the 'as sprayed' condition means homogenising heat treatments can often be avoided. Because of the complex solidification path (i.e. the rapid transition from superheated melt to solid, liquid or semi-solid droplet to temperature equilibration at semi-solid billet top and final slow cooling to fully solid) of the spray formed material, extended solubility of alloying elements and the formation of metastable and quasi-crystalline phases has also been reported.
One of the major attractions of spray forming is the potential economic benefit to be gained from reducing the number of process steps between melt and finished product. Spray forming can be used to produce strip, tube, ring, clad bar / roll and cylindrical extrusion feed stock products, in each case with a relatively fine-scale microstructure even in large cross-sections. The benefits of GASF over powder metallurgy accrue from the reduced number of process steps where powder sieving, pressing, de-gassing and handling steps and their attendant safety and contamination issues may be removed.
Disadvantages.
There are two major disadvantages to the gas atomisation spray forming process. The most significant disadvantage is the relatively low process yield with typical losses of ~30%. Losses occur because of overspray (droplets missing the emerging billet), splashing of material from the billet surface, and material 'bouncing' off the semi-solid top surface. Many operators of the spray forming process now use a particle injector system to re-inject the overspray powder, and thus recycle material that would otherwise be lost, or sell the overspray powder as a product in its own right. The second major disadvantage is one of process control. As it is essentially a free-forming process with many interdependent variables, it has proved difficult to predict the shape, porosity or deposition rate for a given alloy. Much of the control is based on operator experience and empirical relationships. It is partly the process complexity and lack of robust process control that has prevented the widespread commercialisation of this process. Some developments using feed-back control have proved successful in improving the variations in billet diameter and improving yield in specific systems but these have yet to find widespread implementation.
Porosity resulting from gas entrapment and solidification shrinkage is a significant problem in spray formed materials. A typical spray formed billet will contain 1-2% porosity with a pore size dependent on alloy freezing range and various process parameters. Hot isostatic pressing (HIP) or thermo-mechanical processing can heal these pores if they are small (less than 30 μm). Despite these disadvantages, spray forming remains an economic process for the production of difficult to manufacture, niche alloys. Large-scale porosity is more difficult to heal effectively and must be minimised by careful process control. In some cases, porosity is controlled by alloy additions which react with dissolved and entrapped gas to form a solid phase, e.g. titanium added to copper billets to form titanium nitride with dissolved and entrapped nitrogen gas. Porosity, even after consolidation, can limit the applications of spray formed material, for example rotating gas turbine components must have zero porosity because of the detrimental effect on high-cycle fatigue (HCF).
Commercialisation.
In spite of the problems associated with the spray forming process there has been sustained industrial interest in spray forming over the last 35 years. Sandvik-Osprey (former Osprey Metals Ltd) of Neath, South Wales holds the patents on the process and have licensed the technology to a range of industries. There are currently approximately 25 licensees operating around the world, ranging from small research and development plants to full-scale commercial operations. Main applications are prematerial for low temperature Nb3Sn super conductors (CuSn), oil drilling equipment (high strength material CuMnNi) and for forming tools (CuAlFe with high Al-content). In all of these applications, research concerns the reconciliation of the cost disadvantages and complexity of spray forming with the demand for high performance alloys in niche applications.
Melting.
The earliest spray forming work was based on a resistively heated electric holding furnace. The melt then passed through a 3 mm diameter Al2O3 nozzle. However the low flow rate made a high superheat necessary to prevent solidification in the nozzle. The next generation melting procedures in spray forming applications were bottom pour induction units, which offer many benefits. In this system, the melting crucible is directly above the atomiser head with a ceramic nozzle feeding directly from the furnace to the atomiser. A stopper rod runs through the melt to the top of the pouring nozzle, the rod is withdrawn when the melt reaches the designated temperature for spraying, typically above the alloy's liquidus. Alternatively a pre-prepared plug of alloy to block the nozzle is used, and at a specified superheat this plug melts allowing the contents of the furnace to drain through the nozzle. Another problem associated with bottom pour furnaces is the change in flow rate associated with the reducing metalo-static head in the crucible. In some cases, introducing an inert gas overpressure during pouring can compensate for this effect.
An alternative approach is the tilt-pour furnace whereby an induction furnace is tilted to pour the melt into a conical tundish that in turn delivers the molten metal to the melt delivery nozzle. The tilt pour system provides the advantage that melting is decoupled from the spraying procedure so that melting problems and remedial solutions do not affect or disturb the critical set-up of the melt delivery nozzle.
In the most complex melting arrangement, used only for production of nickel superalloy turbine forging blanks by spray forming, vacuum induction melting, electroslag re-melting and cold hearth crucibles have been combined by GE to control alloy impurity levels and the presence of refractory inclusions in the molten metal supply. "Clean metal spray forming" ("CMSF") combines the electroslag refining process, cold walled induction guide and gas atomised spray forming. This approach has led to a reduction in the number of melt related defects (pores, inclusions, etc.), a finer average grain size, the ability to produce larger ingots and the ability to process a wider range of alloys.
Atomisation.
There are many different techniques for atomisation of molten metals, many of which are derived from the powder metallurgy industry and have been extensively reviewed elsewhere. There are two major atomisation techniques used in spray forming: centrifugal atomisation for the manufacture of near net shape rings and gas atomisation for the manufacture of billets, tube and strip.
Centrifugal atomisation.
Centrifugal atomisation involves pouring molten metal at relatively low flow rates (0.1– 2 kg/min) onto a spinning plate, dish or disc, whereby the rotation speed is sufficient to create high centrifugal forces at the periphery and overcome surface tension and viscous forces so the melt is fragmented into droplets. Droplet diameters produced by centrifugal atomisation are dependent primarily on the rotation speed, (up to 20,000 rpm) and are typically in the range 20–1000 μm with cooling rates of the order 104 Ks−1. Centrifugal atomisation is generally conducted under an inert atmosphere of Ar or N2 to prevent oxidation of the fine droplets or can be operated under vacuum.
Gas atomisation.
The melt stream exits the melt delivery nozzle into the spray chamber. The melt stream is protected from being destabilised by the turbulent gas environment in the spray chamber by primary gas jets operating at intermediate inert gas pressure of 2 to 4 bar, the resulting gas flow is parallel to the melt stream to stabilise the melt stream. The secondary atomiser uses high velocity (250 to 350 ms−1), high-pressure (6 to 10 bar) gas jets to impinge on the melt stream to achieve atomisation. The atomiser jets are usually arranged as an annulus or as discrete jets positioned symmetrically about the melt delivery nozzle, or less commonly, arranged as a linear nozzle for the production of strip products. Typical droplet diameters follow a log-normal distribution with powder diameters up to ~600 μm with a mass median diameter of ~150 μm.
The atomising gas mass flow rate to molten metal mass flow rate ratio is a key parameter in controlling the droplet diameter and hence the cooling rate, billet temperature and resulting solid particle nucleant density. The gas-metal ratio (GMR) is typically in the range 1.5 to 5.5, with yield decreasing and cooling rates in the spray increasing with increasing GMR. Typically at low (1.5) GMR, yield is 75%, if the GMR is increased to 5.0 with all other parameters remaining constant, the process yield is reduced to 60%.
Scanning atomisers have been developed which allow the production of billets of up to 600 mm diameter, approximately twice the diameter possible with a static atomiser. The atomiser head is oscillated mechanically through 5 to 10° at a typical frequency of 25 Hz, to deflect the melt stream creating a spray path that is synchronised with the rotation speed of the collector plate in order to deposit a parallel-sided billet. By using programmable oscillating atomiser drives it was possible to improve the shape and shape reproducibility of spray formed deposits. It has been demonstrated that parallel sided, flat topped billets could be sprayed in a reproducible manner if the substrate rotation and atomiser oscillation frequency were synchronised and optimised for specific alloys and melt flow rates. Twin atomiser systems combine a static and scanning atomiser, making it possible to spray billets of up to 450 mm diameter with economic benefits.
Atomising gas used in spray forming is generally either N2 and can be either protective or reactive depending on the alloy system, or Ar which is generally entirely inert but more expensive than N2. Reactive gasses can be introduced in small quantities to the atomising gas to create dispersion strengthened alloys e.g. 0.5–10% O2 in N2 used to generate oxide dispersion strengthened (ODS) Al alloys. Comparisons of N2 and Ar based spray forming showed that with all other factors remaining constant, the billet top temperature was lower with N2 than with Ar, because of the differences in thermal diffusivity of the two atomising gases: Ar has a thermal conductivity of 0.0179 W/mK which is approximately a third less than N2 with a thermal conductivity of 0.026 W/mK.
The mechanisms of melt break up and atomisation have been extensively researched, showing that atomisation typically consists of 3 steps: (1) primary break up of the melt stream; (2) molten droplets and ligaments undergo secondary disintegration; (3) particles cool and solidify. Theoretical analysis of the atomisation process to predict droplet size has yielded models providing only moderate agreement with experimental data.
Investigations show that in all cases gas atomisation of molten metal yields a broad range of droplet diameters, typically in the range 10-600 μm diameter, with a mean diameter of ~100 μm. Droplet diameter governs the dynamic behaviour of the droplet in flight which in turn determines the time available for in-flight cooling which is critical in controlling the resulting billet microstructure. At a flight distance of 300–400 mm, predictions show droplet velocities of 40-90 ms−1 for droplet diameters in the range 20-150 μm respectively, compared to measured velocities of ~100 ms−1, and at distances of up to 180 mm from the atomiser, droplets were still being accelerated by the gas. Droplets cool in-flight predominantly by convection and radiation, and can experience undercooling of up to prior to nucleation. Models and experimental measurements show that small droplets (200 μm will be liquid at deposition. The range of droplet dynamic and thermal histories result in a billet top surface of 0.3 to 0.6 solid fraction. Not all material that impacts the surface is incorporated into the billet: some solid droplets will bounce or splash-off the billet top surface or be directed out of the deposition region by turbulent gas movement in the chamber. The proportion of droplets that impact the surface compared to the proportion that are incorporated into the billet has been termed the "sticking efficiency": dependent on the geometric sticking which is a function of the spray angle relative to substrate and the thermal sticking efficiency dependent on spray and billet solid/liquid fraction.
Spray formed microstructure.
During spraying it is essential to maintain a constant top surface temperature and hence maintain steady-state conditions if a billet with consistent microstructure is to be produced. At the billet surface, during spraying an enthalpy balance must be maintained where the rate of enthalpy lost (Hout) from the billet by conduction to the atomising gas and through the substrate, convection and radiation must be balanced with the rate of enthalpy input (Hin) from the droplets in the spray. There are a variety of factors that can be adjusted in order to maintain these conditions: spray height, atomiser gas pressure, melt flow rate, melt superheat and atomiser configuration, being those parameters most readily adjusted. Typically equipment such as closed circuit cameras and optical pyrometry can be used to monitor billet size/position and top surface temperature. If Hout is much greater Hin then a steady temperature is maintained at the billet top surface. The top surface should be in a mushy condition in order to promote sticking of incoming droplets and partial re-melting of solid particles. The necessary partial re-melting of solid droplets explains the absence of dendritic remnants from pre-solidified droplets in the final microstructure. If Hin is insufficient to cause significant re-melting, a 'splat' microstructure of layered droplets will form, typical of thermal spray processes such as vacuum plasma spraying (VPS), arc spraying and high velocity oxy-fuel. Processing maps have been produced for plasma spraying and spray forming using a steady-state heat balance in terms of the interlayer time (time between deposition events) against average deposition rate per unit area. These maps show the boundaries between banded un-fused microstructure and an equiaxed homogeneous structure.
The final phase of solidification occurs once droplets have impacted the mushy billet surface and thermal equilibration has taken place between the droplets and the billet. At this stage residual liquid is present as continuous network delineating polygonal grain boundaries, with a typical liquid fraction of 0.3 – 0.5. The cooling rates during solidification of the billet is several orders of magnitude slower than the cooling rate in the spray, at 1-20 Ks−1.
Although one of the benefits of spray forming is purportedly the ability to produce bulk material with fine scale microsegregation and little or no macrosegregation work on Al-Mg-Li-Cu alloys showed that as a consequence of the interconnected liquid in the billet there was significant macrosegregation in large spray formed wrought Al billets. The distribution of Cu, Mg and Li in, for example, Al alloy 8091 showed surprisingly pronounced macrosegregation with the variation of Cu(wt%) in a spray formed 8091 billet, ranging from approximately 1.4 at the billet centre to 1.92 at the billet periphery. These macrosegregation patterns were explained in terms of inverse segregation in which solute rich liquid from the billet centre is sucked back through the primary Al-rich network to feed solidification shrinkage at the billet periphery. This effect was suggested to be exacerbated by centrifugal effects from the billet rotation.
As sprayed the billet porosity is typically 1–2% with a region of higher porosity in the splat-quenched region adjacent to the substrate. The very top of the billet often shows increased porosity because the top is rapidly chilled by the atomising gas which continues to chill the billet for 10–60 seconds after spraying. There has also been little progress in understanding and quantifying the underlying physics that controls as-sprayed porosity.
In most cases, the higher porosity at the billet base and top are scalped and recycled. Ultrasonic inspection is sometimes used to determine the depth of the chill zone regions to prevent unnecessary wastage. Depending on the alloy system and the final application, the remaining bulk material is usually processed to close porosity and subjected to a range of thermo-mechanical treatments. Spray formed materials are rarely used in the as-sprayed condition and are often treated by HIPing to remove porosity. In some cases, the residual atomising gas in pores may react with alloying elements to form allegedly beneficial phases e.g. N2 reacting with titanium in nickel superalloy Rene 80 to form a dispersion of TiN.
References.
The above text is substantially taken from 'Spray forming of Si-Al alloys for thermal management applications' By Dr Al Lambourne, D.Phil Thesis, 2007, Queens College. This document is publicly held in the Oxford University Library and is available as an online resource via Oxford Research Archives (ORA). To link to this thesis follow :.


Lada Saint Petersburg

Lada Saint Petersburg is a Russian car manufacturing company owned by AvtoVAZ and headquartered in Saint Petersburg. The company was established in 2006 as a Nissan subsidiary focused on crossover assembly with the name Nissan Manufacturing Rus and started production in 2009. In 2022, it was acquired by NAMI which sold it to AvtoVAZ. The company adopted its present name in June 2023.
History.
In 2006, Nissan began building an assembly facility with capacity to produce up to 50,000 vehicles per year at the village of Pargolovo in Saint Petersburg, incorporating it as Nissan Manufacturing Rus LLC  in June 2006. The facility became operational in June 2009 and it produced various crossovers as the X-Trail, Murano and Qashqai. By 2014, it was expanded to produce up to 100,000 vehicles per year.
In March 2022, following a lack of components as a result of sanctions derived from the 2022 Russian invasion of Ukraine, Nissan Manufacturing Rus halted operations. In November 2022, the state enterprise NAMI acquired Nissan Manufacturing Rus (including its assembly plant, a research and development facility, and the Moscow marketing and sales offices) for a "symbolic price" with a six-year buyback option for Nissan. In February 2023, NAMI sold 99% of the company in turn to its AvtoVAZ subsidiary for . AvtoVAZ announced plans to use the Nissan Manufacturing Rus plant to assemble C and D-segment vehicle kits from other manufacturers, under the Lada badging. In June 2023, the company was officially re-registered as Lada Saint Petersburg LLC. That same month, Lada Saint Petersburg announced its first model, the Lada X-Cross 5 crossover, a badge engineered Bestune T77 from FAW.


Friction extrusion

Friction extrusion is a thermo-mechanical process that can be used to form fully consolidated wire, rods, tubes, or other non-circular metal shapes directly from a variety of precursor charges including metal powder, flake, machining waste (chips or swarf) or solid billet. The process imparts unique, and potentially, highly desirable microstructures to the resulting products. Friction extrusion was invented at The Welding Institute in the UK and patented in 1991. It was originally intended primarily as a method for production of homogeneous microstructures and particle distributions in metal matrix composite materials.
Description of the Process and Essential Process Variables.
As in conventional extrusion processes, in friction extrusion, a shape change is enforced on the charge by forcing its passage through a die. However, friction extrusion differs from conventional extrusion in several key ways. Critically, in the friction extrusion process, the extrusion charge (billet or other precursor) rotates relative to the extrusion die. In addition, similar to conventional extrusion, an extrusion force is applied so as to push the charge against the die. In practice either the die or the charge may rotate or they may be counter-rotating. The relative rotary motion between the charge and the die has several significant effects on the process. First, the relative motion in the plane of rotation leads to large shear stresses, hence, plastic deformation in the layer of charge in contact with and near the die. This plastic deformation is dissipated by recovery and recrystallization processes leading to substantial heating of the deforming charge. Because of the deformation heating, friction extrusion does not generally require preheating of the charge by auxiliary means potentially resulting in a more energy efficient process. Second, the substantial level of plastic deformation in the region of relative rotary motion can promote solid state welding of powders or other finely divided precursors, such as flakes and chips, effectively consolidating the charge (friction consolidation) prior to extrusion. Scrolled features on the face of the die aid material flow into the extrusion orifice which can lead to order of magnitude reduction in extrusion force compared to conventional extrusions of equivalent cross section. Third, the combined effects of elevated temperature and large levels of deformation normally lead the extrudate to have a relatively fine, equiaxed, grain structure which results from recrystallization after the conclusion of deformation: desirable crystallographic textures may also be created by the process and formation of nanocomposite structures are also possible. Based on the foregoing, it can be said that the essential controlled parameters in friction extrusion are typically:
The corresponding response parameters include:
Friction Extrusion Equipment.
In principle, friction extrusion can be performed on any machine which can produce the required rotary and linear motions between the die and charge. Examples include machines built for friction stir welding, milling machines modified to accommodate the extrusion forces, and purpose built friction extrusion equipment such as the shear assisted processing and extrusion (ShAPE™) machine at the Pacific Northwest National Laboratory. Figures 1-3 show examples of friction extrusion equipment and extruded products. Figure 4 shows typical friction extrusion dies designed for production of wire, rod and tube. Dies are rotated in the direction which enhances material flow toward the extrusion orifice during the process.
Strain in Friction Extrusion.
In conventional extrusion, the strain imparted to the charge is loosely defined by the extrusion ratio. The extrusion ratio is simply the cross-sectional area of the extrusion billet, A0, divided by the cross sectional area of the extrudate, Af. The extrusion strain is then e=ln(A0/Af).
In friction extrusion there is an additional strain component which will arise from the shearing motion of the rotating die as it contacts the charge. The strain produced by the rotation of the die results in redundant work as it does not accomplish a shape change. In order to investigate the strain due to shearing, studies have been performed with marker materials embedded in the material to be extruded. After extrusion, these materials are detected by metallographic methods and provide insight regarding the way in which material flows during the extrusion process. Figure 5 shows an example of how the amount of shear strain changes with changing ratios of extrusion rate to die rotation rate. In the limit of very high extrusion rates, the friction extrusion process closely mimics the conventional extrusion process with respect to strain levels.
Typical microstructure resulting from friction extrusion.
Figure 6 shows the cross section and microstructure of a titanium wire produced by friction extrusion of Ti-6-4 powder. Notably, the cross section is fully consolidated and the transformed b microstructure indicates that extrusion likely occurred near 1000 °C (above the beta transus for the alloy). Figure 7 shows grain size and crystallographic orientation typical of thin walled tubing extruded from AZ91 melt spun flake. Grains are refined to less than 5 mm and orientation of the (0001) planes are off-normal due to the rotational shear component. Figure 8 shows examples of friction extruded magnesium alloy tubes. Friction consolidation has also been used to refine grain size and preferentially orient texture in functional materials such as bismuth-telluride thermoelectrics and iron-silicon magnets. Examples of the effect of friction extrusion of microstructure have been reported for AZ31, various aluminum alloys and pure copper.


Superplastic forming and diffusion bonding (SPF/DB) is a technique allowing the manufacture of complex-shaped hollow metallic parts. It combines Superplastic forming (SPF) with a second element "Diffusion Bonding" to create the completed structures.
Principle.
Two metal sheets are welded together at their edges, then heated within the confines of a female mould tool.
When the part is hot, an inert gas is injected between the two sheets ; the part becomes hollow to the form of the mould. Parts may be welded in other areas than the edges to give an internal structure as the sheets are blown.


OPEX (corporation)

OPEX Corporation is a manufacturing company based in Moorestown, New Jersey. They primarily manufacture warehouse automation equipment, high volume mailroom automation equipment, document scanners, and remittance processors. Their warehouse automation products have been implemented at retail and e-commerce companies such as: HBC, BOXED, and iHERB
OPEX employs approximately ~1600 people throughout the world with locations in Moorestown Township, New Jersey USA, Plano, Texas, Bolton, England, Villebon Sur Yvette, France, and Wiesbaden, Germany.


Abbe error

Abbe error, named after Ernst Abbe, also called sine error, describes the magnification of angular error over distance. For example, when one measures a point that is 1 meter away at 45 degrees, an angular error of 1 degree corresponds to a positional error of over 1.745 cm, equivalent to a distance-measurement error of 1.745%.
In machine design, some components are particularly sensitive to angular errors. For example, slight deviations from parallelism of the spindle axis of a lathe to the tool motion along the bed of the machine can lead to relatively large (undesired) taper along the part (i.e. a non-cylindrical part). Vernier calipers are not free from abbe error, while screw gauges are free from abbe error. Abbe error is the product of the abbe offset and the sine of angular error in the system.
Abbe error can be detrimental to dead reckoning.
Formula:
formula_2 the error.
formula_3 the distance.
formula_4 the angle.


Tube drawing

Tube drawing is a process to size a tube by shrinking a large diameter tube into a smaller one, by drawing the tube through a die. This process produces high-quality tubing with precise dimensions, good surface finish, and the added strength of cold working. For this reason this process is established for many materials, mainly metalworking but also glass. Because it is so versatile, tube drawing is suitable for both large- and small-scale production. The large-scale production of glass typically uses a one step process where glass is directly drawn into a tube from a melting tank.
There are five types of tube drawing: tube sinking, mandrel drawing, stationary mandrel, moving mandrel, and floating mandrel. A mandrel is used in many of the types to prevent buckling or wrinkling in the workpiece.
Processes.
Tube sinking.
Tube sinking, also known as "free tube drawing", reduces the diameter of the tube without a mandrel inside the tube. The inner diameter is determined by the inner and outer diameter of the stock tube, the outer diameter of the final product, the length of the die landing, the amount of back tension, and the friction between the tube and the die. This type of drawing operation is the most economical, especially on thick-walled tubes and tubes smaller than in diameter, but does not give the best surface finish. As the tube thickness increases the surface finish quality decreases. This process is often used for the tubing on low-cost lawn furniture.
Rod drawing.
Rod drawing is the process that draws the tube with a mandrel inside the tube; the mandrel is drawn with the tube. The advantage to this process is that the mandrel defines the inner diameter and the surface finish and has a quick setup time for short runs. The disadvantages are that lengths are limited by the length of the mandrel, usually no more than , and that a second operation is required to remove the mandrel, called "reeling". This type of process is usually used on heavy walled or small (inner diameter) tubes. Common applications include super-high pressure tubing and hydraulic tubing (with the addition of a finishing tube sinking operation). This process is also used for precision manufacturing of trombone handslides.
Fixed plug drawing.
Fixed plug drawing, also known as stationary mandrel drawing, uses a mandrel at the end of the die to shape the inner diameter of the tube. This process is slow and the area reductions are limited, but it gives the best inner surface finish of any of the processes. This is the oldest tube drawing method.
Floating plug drawing.
Floating plug drawing, also known as floating mandrel drawing, uses a mandrel that is not anchored whatsoever to shape the inner diameter of the tube. The mandrel is held in by the friction forces between the mandrel and the tube. This axial force is given by friction and pressure. The greatest advantage of this is that it can be used on extremely long lengths, sometimes up to . The disadvantage is it requires a precise design otherwise it will give inadequate results. This process is often used for oil-well tubing.
Tethered plug drawing.
Tethered plug drawing, also known as semi-floating mandrel drawing, is a mix between floating plug drawing and fixed plug drawing. The mandrel is allowed to float, but is still anchored via a tether. This process gives similar results to the floating plug process, except that it is designed for straight tubes. It gives a better inner surface finish than rod drawing.


Vibratory finishing

Vibratory finishing is a type of mass finishing manufacturing process used to deburr, radius, descale, burnish, clean, and brighten a large number of relatively small workpieces.
In this batch-type operation, specially shaped pellets of media and the workpieces are placed into the tub of a vibratory tumbler. The tub of the vibratory tumbler and all of its contents are then vibrated. The vibratory action causes the media to rub against the workpieces which yield the desired result. Depending on the application this can be either a dry or wet process.
Unlike rotary tumbling this process can finish internal features, such as holes. It is also quicker and quieter. The process is performed in an open tub so the operator can easily observe if the required finish has been obtained.
Vibratory tumblers.
Vibratory tumblers have an action that is similar to filing. An eccentric, rotating weight shakes the tub in a circular path, during which the entire load is lifted up at an angle and then dropped. As the load is falling (but not actually airborne) the tub returns to an upward position, applying an upward and angular force that causes a shearing action where the parts and media rub against each other.
Vibratory finishing systems tend to produce a smooth finish because the media essentially laps the parts. Since the load is moving as a unit, fragile parts are safe in the vibrator. There is no tearing action or unequal forces that tend to bend and distort parts. The larger the parts or media are, the faster the cutting action.
The frequency and amplitude of the machine controls the finish of the parts. The frequencies can vary from 900 to 3600 cycles per minute (CPM) and the amplitude can vary from 0 to . High frequencies, 1800 CPM or greater, and small amplitudes are used for fine finishes or delicate parts, whereas large amplitudes are used for heavier cutting. High frequencies and amplitudes can roll burrs and peen edges. The circulation of parts is best at higher frequencies, therefore, heavy pieces are run at these high frequencies with moderate amplitudes of .
Despite the apparent rubbing action of particles against parts, studies show that the primary mechanism of material removal in vibratory finishing is erosion caused by the relatively normal impacts of particles on parts. These impacts occur at the same frequency as the vibration, and at impact velocities of less than 1 m/s.
Media.
Any material or substance which is used to give finish or final touch to any part or product is classified as media. Typical media are performed in a rigid molded shape containing a bonding agent. These media work by continual exposure to abrasive particles, as the adhering agent, wears out during the usage of material.
All the tumbling media have some basic functions in common. These are able to provide some support to parts preventing them from mechanical damage, keep parts separate, supply abrasive, improve tumbling action, deburr and also serve as a carrier for the compound.
The 9 Benefit of Tumbling Media


Cold sizing

Cold sizing is a squeezing operation performed at temperatures significantly below the melting point to finish the surface of a workpiece to ensure better dimensional accuracy and surface finish.
The sizing operation is a squeezing operation that minimizes the thickness of the metal. Sizing is performed in an open die and only the surface where the die and workpiece touch will be sized. Many ferrous metal castings are sized to sharpen corners and flatten holes around piercings. Sizing pressure is determined by area to be sized, the metal used, and the change in metal thickness from the operation. Sizing is usually performed on semi-finished parts or parts that require an accurate finish. Stop blocks are used to ensure close tolerances.
Cold sizing, like all other cold forming processes, has a hot process counterpart. In addition to semi-finished parts, cold forming may be used on metal stock, sheet, bar, and rod stock. Cold sizing can be performed on various metals, both ferrous and non-ferrous, and even materials like polymers and plastics. Sizing is related to other squeezing operations like swaging, coining, hobbing, staking and riveting, thread rolling, and extruding.
Although the whole workpiece may be inserted into the die, the sizing operation can give dimensional accuracy to a portion of the part based on the contact with the die. Sizing is mostly used to give a forged or cast part better dimensional accuracy. Mated surfaces between touching parts like gears are often sized. The sizing operation also provides a better surface hardness and finish to the workpiece. Also, the sized surface of the workpiece gets denser and stronger when the operation is performed. The dimensional tolerance of the operation is about . Primary pressing or a compacting die are typically used when sizing small batches of compact. To keep costs down, larger batches of compact usually have a specialized die made specifically for the operation.
Troubleshooting.
This process is designed to achieve the desired dimensional tolerances of the forged parts. Elastic die deflection has been a problem in this operation so two solutions were developed. One solution is to make corrections in the die based on the elastic die deflection. It can be determined how much the workpiece distorted from the desired shape using a finite element analysis (FEA). This analysis is the basis the corrections are made on. The other solution is to apply a counter pressure by inserting an elastomer ring into the lower die in order to compensate the elastic die deflection.


Embossing (manufacturing)

Sheet metal embossing is a stamping process for producing raised or sunken designs or relief in sheet metal. This process can be made by means of matched male and female roller dies, or by passing sheet or a strip of metal between rolls of the desired pattern. It is often combined with foil stamping to create a shiny, 3D effect.
Process.
The metal sheet embossing operation is commonly accomplished with a combination of heat and pressure on the sheet metal, depending on what type of embossing is required. Theoretically, with any of these procedures, the metal thickness is changed in its composition.
Metal sheet is drawn through the male and female roller dies, producing a pattern or design on the metal sheet. Depending on the roller dies used, different patterns can be produced on the metal sheet. The pressure and a combination of heat actually "irons" while raising the level of the image higher than the substrate to make it smooth. The term "impressing" refers to an image "lowered" into the surface of a material, in distinction to an image "raised" out of the surface of a material.
In most of the pressure embossing operation machines, the upper roll blocks are stationary, while the bottom roll blocks are movable. The pressure with which the bottom roll is raised is referred to as the tonnage capacity.
Embossing machines are generally sized to give of strip clearance on each side of an engraved embossing roll. Many embossing machines are custom-manufactured, so there are no industry-standard widths. It is not uncommon to find embossing machines in operation producing patterns less than wide all the way up to machines producing patterns wide or more.
Characteristics.
The metal embossing manufacturing process has these characteristics:
Commonly used materials.
The following materials are suitable for embossing:


Roll slitting

Roll slitting is a shearing operation that cuts a large roll of material into narrower rolls. There are two types of slitting: log slitting and rewind slitting. In log slitting the roll of material is treated as a whole (the 'log') and one or more slices are taken from it without an unrolling/re-reeling process. In rewind slitting the web is unwound and run through the machine, passing through knives or lasers, before being rewound on one or more shafts to form narrower rolls. The multiple narrower strips of material may be known as "mults" (short for multiple) or "pancakes" if their diameter is much more than their width. For rewind slitting the machine used is called a slitter rewinder, a slitter or a slitting machine – these names are used interchangeably for the same machines. For particularly narrow and thin products, the pancakes become unstable, and then the rewind may be onto a bobbin-wound reel: the rewind bobbins are much wider than the slit width and the web oscillates across the reel as it is rewound. Apart from the stability benefit it is also then possible to put very long lengths, (frequently many tens of kilometres), onto one bobbin.
Process.
Soft materials.
Several methods are available for soft materials like plastic films, textiles, adhesive tapes, and paper. Razor blades, straight, or circular blades are being used. Some blades cut through the material while others crush the material against a hard roll. Those are similar to knives. The cutting blades can be set to a desired width. Some machines have many blades and can produce a number of output rolls at once. The slit material is rewound on paper, plastic or metal cores on the exit side of the machine.
The process is used because of its low cost and high precision for mass production. Some machines have a program that monitors the blades and sharpens the blades often to maintain the quality and precision of the cut. Depending on the industry and the product that is being slit these machine can run between 10m/min (special metal webs) and 5000 m/min (paper making process). The machines can also incorporate extensive automation to precisely control material tension, automatically position the slitting knives, automatically align the cores onto which the material is wound and to reduce manual handling of the rolls.
Examples of materials that can be cut this way are: adhesive tape, foam, rubber, paper products, foil, plastics (such as tarps and cling wrap), glass cloth, fabrics, release liner and film.
Hard materials.
For harder materials, such as sheet metal, blades cannot be used. Instead, a modified form of shearing is used. Two cylindrical rolls with matching ribs and grooves are used to cut a large roll into multiple narrower rolls. This continuous production process is economical yet precise; usually more precise than most other cutting processes. However, the occurrence of rough edges known as burrs is commonplace on slit edges. Also, the geometry of these rolls is determined by specific tolerances in addition to the type of material and workpiece thickness.
Machinery.
For metal coils, the slitter consists of three main parts: an uncoiler, slitter, and recoiler. The material is fed from the uncoiler, through the nip between the two circular cutting wheels (one on top and another underneath), and then re-wound in slit pieces on the recoiler.
When the term "slitter rewinder" or "slitting machine" is used to describe the machine, the three parts are referred to as the unwind, the slitting section and the rewind. Slitter rewinders are normally used to slit plastic films, paper and metal foils. The unwind stage holds the roll stably and allows it to spin; it is either braked or driven to maintain accurate tension in the material. Some machines have a driven unwind which reduces the effect of inertia when starting to unwind heavy rolls or when the material is very tension-sensitive.
The slitting section has four main options:
The rewind section also has options. The main type is centre winding using differential rewind shafts. These shafts are becoming universal on most slitting machines. The differential shafts ensure an even tension across the full width of the material. Closed-loop control of the winding tension using feedback from load cells provides the total tension-control system required for running tension-sensitive materials. Precise and accurate tension control is the key to good roll slitting. Modern machines use AC vector drives with closed-loop feedback from AC motors. When used with the correct control algorithms, they produce excellent results with the minimum of maintenance.
Industry usage.
Roll slitting is a technique heavily used by Converters (industry). The converter industry normally refers to companies who print, coat and laminate materials. A typical converter is a company that produces flexible packaging material for packaging food. This may involve purchasing large rolls of plastic film such as biaxially orientated polypropylene (BOPP) which is then printed to the customer's design and coated with cold seal adhesive for use on high speed packaging machines. This material is printed and coated in wide, large diameter rolls for maximum efficiency. The rolls are then slit, using a slitting machine, into smaller rolls of the size to be used on the packaging machine.


Percussion welding

Percussion welding (PEW) is a type of resistance welding that blends dissimilar metals together. Percussion welding creates a high temperature arc that is formed from a short quick electrical discharge. Immediately following the electrical discharge, pressure is applied which forges the materials together. This type of joining brings the materials together in a percussive manner.
Percussion welding is similar to flash welding and upset welding but is generally considered to be more complex because it uses an electric discharge at the joint, followed by pressure being applied to join the materials together. Percussion welding is used to join dissimilar metals together, or used when flash is not required at the joint. Percussion welding is used on materials that have small cross sectional areas.
Advantages of using percussion welding types include a shallow heat affected zone, and the time cycle involved is very short. Typical times can be found to be less than 16 milliseconds.


Haldyn Glass

Haldyn Glass Limited (HGL) is a listed company at Bombay Stock Exchange in India (BSE: 515147) (ISIN Code 506D01012) manufacturing clear glass containers. Promoted by Haldyn Corporation Limited having its manufacturing plant in Vadodara, Gujarat while its administrative office is located in Goregaon East, Mumbai. Haldyn Glass Limited (HGL) was incorporated in the year 1991. N.D. Shetty is the Chairman and Mr. Tarun N. Shetty is Managing Director of the company.
The manufacturing plant of HGL is located at Village Gavasad, Taluka Padra, District Vadodara, in the state of Gujarat. Currently has total melting capacity of 360 tons per day with 8 I.S. machines which gives us leverage over the competition in manufacturing a very wide range of containers from 90 ml to 1000 ml. The I.S. machines are capable of producing 2 million high quality containers every day.Value-addition is also facilitated through the decoration facilities, consisting of modern multi-colour printing machines.
The Company specializes in Soda Lime Flint glass containers catering to wide range of national & international customers, across the liquor, food & beverage and cosmetic industries.
In 2015, Haldyn Glass Ltd entered into Joint Venture (JV) with Heinz Glas International GMBH, Germany, for the manufacturing of perfume and cosmetic glass bottles for the export and local market. The joint venture company established is Haldyn Heinz Fine Glass Pvt. Ltd