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Metalworking Terminology
This article is a list of terms commonly used in the practice of metalworking – the science, art, industry, and craft of shaping metal. Processes The following is a categorical list of metalworking processes: operations, procedures, techniques, and other actions performed that pertain to or consist of metalworking. Casting Casting is the process of creating objects by filling a mold with molten metal and allowing it to cool. *Centrifugal casting (industrial), Centrifugal *Continuous casting, Continuous *Die casting, Die *Evaporative-pattern casting, Evaporative-pattern **Full-mold casting, Full-mold **Lost-foam casting, Lost-foam *Investment casting, Investment ** in art: Lost-wax casting, Lost-wax *Permanent mold casting, Permanent mold *Plaster mold casting, Plaster mold *Sand casting, Sand *Semi-solid metal casting, Semi-solid metal *Ceramic mold casting#Shaw process, Shaw process *Shell molding *Spin casting, Spin Related terms *Foundry *Crucible *Molding sand *Refracto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceramic Mold Casting
Ceramic mold casting, also known ambiguously as ceramic molding, is a group of metal casting processes that use ceramics as the mold (manufacturing), mold material. It is a combination of plaster mold casting and investment casting. There are two types of ceramic mold casting: the ''Shaw process'' and the ''Unicast process''. These casting processes are commonly used to make Machine tooling, tooling, especially drop forging die (manufacturing), dies, but also injection molding dies, die casting dies, glass molds, stamping (metalworking), stamping dies, and extrusion dies. Shaw process The ', also known as the ', uses a mixture of refractory aggregate, hydrolyzed ethyl silicate, Alcohol (chemistry), alcohol, and a gelling agent to create a mold. This slurry mixture is poured into a slightly tapered flask (casting), flask and a reusable pattern (''i.e.'' the item used to create the shape of the mold) is used. The slurry hardens almost immediately to a rubbery state (the consistency o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidising
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: * Electron-transfer – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * Atom transfer – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously, the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forge Weld
Forge welding (FOW), also called fire welding, is a solid-state welding process that joins two pieces of metal by heating them to a high temperature and then hammering them together. It may also consist of heating and forcing the metals together with presses or other means, creating enough pressure to cause plastic deformation at the weld surfaces. The process, although challenging, has been a method of joining metals used since ancient times and is a staple of traditional blacksmithing. Forge welding is versatile, being able to join a host of similar and dissimilar metals. With the invention of electrical welding and gas welding methods during the Industrial Revolution, manual forge-welding has been largely replaced, although automated forge-welding is a common manufacturing process. Introduction Forge welding is a process of joining metals by heating them beyond a certain threshold and forcing them together with enough pressure to cause deformation of the weld surfaces, creating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forging
Forging is a manufacturing process involving the shaping of metal using localized compression (physics), compressive forces. The blows are delivered with a hammer (often a power hammer) or a die (manufacturing), die. Forging is often classified according to the temperature at which it is performed: cold forging (a type of cold working), warm forging, or hot forging (a type of hot working). For the latter two, the metal is heated, usually in a forge. Forged parts can range in weight from less than a kilogram to hundreds of metric tons.Degarmo, p. 389 Forging has been done by metalsmith, smiths for millennia; the traditional products were kitchenware, household hardware, hardware, hand tools, edged weapons, cymbals, and jewellery. Since the Industrial Revolution, forged parts are widely used in mechanism (engineering), mechanisms and machines wherever a component requires high strength of materials, strength; such forgings usually require further processing (such as machining) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drawing (manufacturing)
Drawing is a manufacturing process that uses tensile forces to elongate metal, glass, or plastic. As the material is drawn (pulled), it stretches and becomes thinner, achieving a desired shape and thickness. Drawing is classified into two types: sheet metal drawing and wire, bar, and tube drawing. Sheet metal drawing is defined as a plastic deformation over a curved axis. For wire, bar, and tube drawing, the starting stock is drawn through a die to reduce its diameter and increase its length. Drawing is usually performed at room temperature, thus classified as a cold working process; however, drawing may also be performed at higher temperatures to hot work large wires, rods, or hollow tubes in order to reduce forces.Degarmo, p. 432.Kalpakjian, pp. 415–419. Drawing differs from rolling in that pressure is not applied by the turning action of a mill but instead depends on force applied locally near the area of compression. This means the maximal drawing force is limited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carburizing
Carburizing, or carburising, is a heat treatment process in which iron or steel absorbs carbon while the metal is heated in the presence of a carbon-bearing material, such as charcoal or carbon monoxide. The intent is to make the metal harder and more wear resistant. Depending on the amount of time and temperature, the affected area can vary in carbon content. Longer carburizing times and higher temperatures typically increase the depth of carbon diffusion. When the iron or steel is cooled rapidly by quenching, the higher carbon content on the outer surface becomes hard due to the transformation from austenite to martensite, while the core remains soft and tough as a ferritic and/or pearlite microstructure. This manufacturing process can be characterized by the following key points: It is applied to low-carbon workpieces; workpieces are in contact with a high-carbon gas, liquid or solid; it produces a hard workpiece surface; workpiece cores largely retain their toughness an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Rolling
In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is similar to the rolling of dough. Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallization temperature, then the process is known as hot rolling. If the temperature of the metal is below its recrystallization temperature, the process is known as cold rolling. In terms of usage, hot rolling processes more tonnage than any other manufacturing process, and cold rolling processes the most tonnage out of all cold working processes... Roll stands holding pairs of rolls are grouped together into rolling mills that can quickly process metal, typically steel, into products such as structural steel (I-beams, angle stock, channel stock), bar stock, and rails. Most steel mills ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Working
In metallurgy, hot working refers to processes where metals are plastically deformed above their recrystallization temperature. Being above the recrystallization temperature allows the material to recrystallize during deformation. This is important because recrystallization keeps the materials from strain hardening, which ultimately keeps the yield strength and hardness low and ductility high.Degarmo, p. 373. This contrasts with cold working. Many kinds of working, including rolling, forging, extrusion, and drawing, can be done with hot metal. Temperature The lower limit of the hot working temperature is determined by its recrystallization temperature. As a guideline, the lower limit of the hot working temperature of a material is 60% its melting temperature (on an absolute temperature scale). The upper limit for hot working is determined by various factors, such as: excessive oxidation, grain growth, or an undesirable phase transformation. In practice materials are usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractory Materials
In materials science, a refractory (or refractory material) is a material that is resistant to Thermal decomposition, decomposition by heat or chemical attack and that retains its strength and rigidity at high temperatures. They are Inorganic compound, inorganic, Nonmetal, non-metallic compounds that may be Porosity, porous or non-porous, and their crystallinity varies widely: they may be Crystal, crystalline, polycrystalline, Amorphous solid, amorphous, or Composite material, composite. They are typically composed of oxides, carbides or nitrides of the following elements: silicon, aluminium, magnesium, calcium, boron, chromium and zirconium. Many refractories are ceramics, but some such as graphite are not, and some ceramics such as clay pottery are not considered refractory. Refractories are distinguished from the ''refractory metals'', which are elemental metals and their alloys that have high melting temperatures. Refractories are defined by ASTM International, ASTM C71 as " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molding Sand
Molding sand, also known as foundry sand, is a sand that when moistened and compressed or oiled or heated tends to pack well and hold its shape. It is used in the process of sand casting for preparing the mold cavity. Green sand Green sand is an aggregate of sand, bentonite clay, pulverized coal and water. Its principal use is in making molds for metal casting. The largest portion of the aggregate is a sand, usually silica or sometimes olivine. There are many recipes for the proportion of clay, but they all strike different balances between moldability, surface finish, and ability of the hot molten metal to degas. The coal, typically referred to in as sea-coal, which is present at a ratio of less than 5%, partially combusts in the surface of the molten metal, leading to the offgassing of organic vapors. Sand casting is one of the earliest forms of casting practiced due to the simplicity of materials involved. It still remains one of the cheapest ways to cast metal because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crucible
A crucible is a container in which metals or other substances may be melted or subjected to very high temperatures. Although crucibles have historically tended to be made out of clay, they can be made from any material that withstands temperatures high enough to melt or otherwise alter its contents. History Typology and chronology The form of the crucible has varied through time, with designs reflecting the process for which they are used, as well as regional variation. The earliest crucible forms derive from the sixth/fifth millennium B.C. in Eastern Europe and Iran. Chalcolithic Crucibles used for copper smelting were generally wide shallow vessels made from clay that lacks refractory properties which is similar to the types of clay used in other ceramics of the time. During the Chalcolithic period, crucibles were heated from the top by using blowpipes.Hauptmann A., 2003, ''Developments in copper Metallurgy During the Fourth and Third Millennia B.C. at Feinan'', Jordan, P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
