. aging : a process generally accelerated by temperature, wherein changes in mechanical properties occur in certain metals. these changes generally raise room temperature hardness, tensile and yield strength, while lowering ductility. aisi : american iron and steel institute. published steel products manual to stainless and heat resisting steels which provides information concerning tolerances, chemical analysis, definitions of technical terms and other related subjects which have been developed in the manufacture and use of stainless steels. alclad : composite sheet produced by bonding either corrosion - resistant aluminum alloy or aluminum of high purity to base metal of structurally stronger aluminum alloy. the coatings are anodic to the core so they protect exposed areas of the core electrolytically during exposure to corrosive environment. alloy : a material that has metallic properties and is composed of two or more chemical elements of which at least one is a metal ( i. e. steel is an alloy of carbon in iron ; stainless steel is an alloy of carbon, chromium and sometimes nickel in iron. ) alloying elements : those elements in alloys which are deliberately added during melting and refining to enhance the properties of that alloy. alloy steel : an iron - based mixture is considered to be an alloy steel when manganese is greater than 1. 65 %, silicon over 0. 5 %, copper above 0. 6 %, or other minimum quantities of alloying elements such as chromium, nickel, molybdenum, or tungsten are present. an enormous variety of distinct properties can be created for the steel by substituting these elements in the recipe. alpha brass : a copper - zinc alloy containing up to 38 % of zinc. used mainly for cold working. alpha bronze : a copper - tin alloy consisting of the alpha solid solution of tin in copper. commercial forms contain 4 or 5 % of tin. this alloy is used in coinage, springs, turbine, blades, etc. alpha iron : the polymorphic form of iron, stable below 1670°f, has a body centered cubic lattice, and is magnetic up to 1410°°f. aluminizing : forming an aluminum or aluminum alloy coating on a metal by hot dipping, hot spraying, or diffusion. annealing : a process involving heating to a temperature at or above critical and cooling at a controlled rate, usually applied to induce softening. the process could alter mechanical properties, physical properties or micro structure. anodizing : ( aluminum adic oxide coating ) a process of coating aluminum by anodic treatment resulting in a thin film of


aluminum standards and data provides definitions for welding and brazing : welding is the " joining of two or more pieces of aluminum by applying heat or pressure, or both, with or without filler metal to produce a localized union through fusion or recrystallization across the interface ". brazing is the " joining of metals by fusion of nonferrous alloys that have melting points above 425 degrees c ( 800 degrees f ) but lower than those of the metals being joined. this may be accomplished by means of a torch ( torch brazing ), in a furnace ( furnace brazing ), or by dipping a molten flux bath ( dip or flux brazing ). " according to the asm specialty handbook : aluminum and aluminum alloys : " brazing, by definition, employs filler metal having a liquidus above 450 degrees c ( 840 degrees f ) and below the solidus of the base metal. brazing is distinguished from soldering by the melting point of the filler metal : solders melt below 450 degrees c ( 840 degrees f ). brazing differs from welding in that no substantial amount of the base metal is melted during brazing. thus the temperatures for brazing aluminum are intermediate between those for welding and soldering. also, brazed aluminum assemblies generally are between welded and soldered assemblies in strength and resistance to corrosion " since soldering is done below 450 degrees c ( 840 degrees f ), aluminum filler alloys are not used in soldering aluminum. instead, solders for aluminum alloys are often zinc, tin, cadmium and lead.


learn something new every day more info... by email information traveling across a computer network or another type of telecommunications network typically comes in packets. packets are smaller, " bite - sized " pieces of a larger chunk of information. although telecommunication technology is generally reliable and seamless from the end - user ' s point of view, that is only because the computer does the dirty work. it constantly sifts through the packets, looking for fraudulent and corrupt data, discarding it when found. a burst error is a string of corrupt data, measured as the length between — and including — the first and last error signals. for example, imagine sending a packet containing all of the letters of the alphabet, a through z. if the recipient ' s computer " opens " the packet and finds that the first letter in the sequence is " q " and the last letter in the sequence is " r, " that is a burst error. the " burst " of data in the packet is corrupt. although in the example the first and last letters are defined as corrupt, that does not mean that every letter within the packet is damaged. imagine that every other letter is as it should be ; only position one, " a, " and position 26, " z, " have been damaged. the number of correct bits of information between the damaged ends is called the guard band. in this case, the guard band would be 24, because there are 24 correct letters separating the two damaged ones. measuring the length of a burst error is simple. it is defined as the number of individual bits separating the very first occurrence of the error from the last occurrence, including the initial and final incorrect bits. in the previous example, the length of the burst error would be 26. the causes of a burst error can vary widely. it is not always possible to measure them accurately. generally, this corruption can occur through any number of sources, including signal degradation, packet loss, other types of network failure, or sending failure on the part of the computer. in networking, as in the real world, sometimes things go wrong. fortunately, most forms of networking provide built in error - checking mechanisms, allowing a receiving computer to compare the actual received data against an impression of the data that was sent, allowing it to recognize whether something has gone wrong along the way.