Forging of metals

G.M. Pharr, W.C. Oliver, 1992, Measurement of Thin Film Mechanical Properties Using Nanoindentation , Materials Research Society Bulletin XVII (July) 28. S.L. Semiatin, G.D. Lahoti, 1981, The Forging of Metals ,... 

A measured quantity of raw, unpolymerized plastic material is introduced into a heated mold which is subsequently closed under pressure, forcing the material into all areas of the cavity as it melts. Analogous to closed die forging of metals (see 2.3F). 

Magnesium alloys are available in a variety of metal forms, including cast ingots, slabs, and billets sand, permanent-mold, die, and investment castings forgings extmded bars, rods, tubes, stmctural and special hoUow and soHd shapes and roUed sheet and plate. Magnesium alloys are used widely in a great variety of appHcations. 

Aluminum alloys are commercially available in a wide variety of cast forms and in wrought mill products produced by rolling, extmsion, drawing, or forging. The mill products may be further shaped by a variety of metal working and forming processes and assembled by conventional joining procedures into more complex components and stmctures. 

Ancient iron structures sometimes show no sign of corrosion or at most, very little. The clean atmosphere of past centuries may be responsible in that it allowed a very thin adherent layer of oxide to develop on the surface [22], This layer very often protects against even today s increasingly aggressive industrial pollutants Very often the conditions of the initial corrosion are the ones that determine the lifespan of metals [23], A well-known example is the sacred pillar of Kutub in Delhi, which was hand forged from large iron blooms in 410 a.d. In the pure dry air, the pillar remains free of rust traces but shows pitting corrosion of the iron... 

The term plastic is not a definitive one. Metals, for instance, are also permanently deformable and are therefore plastic. How else could roll aluminum be made into foil for kitchen use, or tungsten wire be drawn into a filament for an incandescent, light bulb, or a 100 ton ingot of steel be forged into a rotor for a generator. Likewise the different glasses, which contain compounds of metals and nonmetals, can be permanently shaped at high temperatures. These cousins to polymers and plastics are not considered plastics within the plastic industry or context of this book. 

A dramatic change in the hardnesses of metallic materials occurred when the smelting of iron was invented in Egypt (4000 BCE). By 1550 BCE, it could be forged into wrought iron which considerably improved its properties. 

Explosive Fabrication of Metals. This term includes explosive forming, -forging, —sizing -welding, —compaction, and -conditioning. 

Explosive Forging. Mentioned but not described under Explosive Fabrication of Metals... 

Aluminum is unique among the metals because it responds to nearly all of the known finishing processes. It can be finished in the softest, most delicate textures as exemplified by tableware and jewelry. Aluminum can be anodized and dyed to appear like gold. It can be made as specular as a silver mirror and jet black. The metal also can be anodized to an extremely hard, wear- and abrasion-resistant surface that approaches the hardness of a diamond. Aluminum is available in many convenient forms-shapes, sheet, plate, ingot, wire, rod and bar, foil, castings, forgings, powdered metals, and extrusions. 

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