Principal Casting Alloys

The foremost use of casting alloys is in the automotive industry (60% of the tonnage world-wide). These are mainly engine components elaborated from alloys with silicon, most of which also contain at least 3% copper 45100 (A-S5U3), 46200 (A-S9U3), etc. 

The main applications outside the automotive industry are in mechanical construction, electrical engineering, transport, household electrical appliances and ironmongery. 

Unalloyed cast aluminium is almost exclusively used for electrical applications. 

These alloys are easy to cast because their eutectic temperature is 575 °C. Most 

These alloys have many applications as structural components in mechanical engineering, in electrical industry and automotive industry. Alloys that contain magnesium are age-hardenable alloys. Their resistance to atmospheric corrosion is excellent. 

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These alloys are available as wrought or cast alloys. The principal metals alloyed with aluminum include copper, manganese, silicon, magnesium, and zinc. These alloys are discussed in considerable detail under Aluminum Alloys. 

These alloys are available as wrought or cast alloys. The principal wrought copper alloys are the brasses, leaded brasses, phosphor bronzes, aluminum bronzes, silicon bronzes, bciylhum coppers, cupronickels. and nickel silvers. The major cast copper alloys include the red and yellow brasses, manganese, tin, aluminum, and silicon bronzes, beryllium coppers, and nickel silvers. The chemical compositions range widely. For example, a leaded brass will contain 60% copper, 36 to 40% zinc, and lead up to 4% a beryllium copper is nearly all copper, containing 2.1% beryllium, 0.5% cobalt, or nickel, or in another formulation, 0.65% beryllium, and 2.5% cobalt. 

What is the principal difference between O wrought and cast alloys ... 

Lea.dAnodes. A principal use for lead—calcium—tin alloys is lead anodes for electrowinning. The lead—calcium anodes form a hard, adherent lead dioxide layer during use, resist corrosion, and gready reduce lead contamination of the cathode. Anodes produced from cast lead—calcium (0.03—0.09 wt %) alloys have a tendency to warp owing to low mechanical strength and casting defects. 

Calcium—Silicon. Calcium—silicon and calcium—barium—siUcon are made in the submerged-arc electric furnace by carbon reduction of lime, sihca rock, and barites. Commercial calcium—silicon contains 28—32% calcium, 60—65% siUcon, and 3% iron (max). Barium-bearing alloys contains 16—20% calcium, 9—12% barium, and 53—59% sihcon. Calcium can also be added as an ahoy containing 10—13% calcium, 14—18% barium, 19—21% aluminum, and 38—40% shicon These ahoys are used to deoxidize and degasify steel. They produce complex calcium shicate inclusions that are minimally harm fill to physical properties and prevent the formation of alumina-type inclusions, a principal source of fatigue failure in highly stressed ahoy steels. As a sulfide former, they promote random distribution of sulfides, thereby minimizing chain-type inclusions. In cast iron, they are used as an inoculant. 

Copper alloys can also be grouped according to how the principal elemental additions affect properties. This grouping depends primarily on whether the additions that dissolve in Hquid copper can form discrete second phases during either melting/casting or in-process thermal treatment. AHoy constitution that relates to limits of soHd solubiUty and equiUbrium phases that form in binary and ternary combinations with copper are found in the Hterature (2,3). 

Approximately 90% of all RPDs are now cast from base metal alloys containing principally chromium, cobalt and nickel, with chromium being the element present in all such alloys. Commonly, these cast chromium alloys contain various alloying elements, typically <5% Mo, <1% Fe, 25-30% Cr and the balance Co although there are some widely used alloys containing... 

Cast iron is the term applied to a wide range of ferrous alloys, whose principal distinguishing feature is a carbon content in excess of l -7<7o. The relatively low melting point of these alloys compared with that of steels and their tendency to expand slightly on solidification, which make them admirably suited for the production of components by casting, result from this feature of their composition. 

The principal difficulties in the production of castings in this alloy are its high shrinkage, which entails some tendency to the development of porosity, and the ready formation of oxide skin, which may cause cold laps in the casting. Castings must in consequence be produced by methods similar to those employed for steel castings and care must be taken to avoid the introduction of oxide into the mould. 

With only a few noticeable exceptions, metals and their alloys possess a distinct shape. To generate the principal shape, metals are said to be wrought or cast. Wrought metals receive their shape through deformation steps cast metals receive their shape through solidification steps. Materials of construction are available in both wrought and cast forms. Each group is discussed separately. 

Representative alloys containing antimony arc described in the Tabic L Metallic antimony is an effective pearlitizing agent for producing pearlitic cast iron, The principal use of antimony, however, is in the form of the oxide Its major application is as a flame retardant for plastics and textiles, Other applications of importance are in glass, pigments, and catalysts. 

FERROCHROMIL M. An alloy, composed principally of iron and chromium, used as a means of adding chromium to steels How. medium, and high-carbon I and cast iron. Available in several classifications and grades, generally containing between 60 to 705( chromium, in crushed sizes and lumps up to 75 pounds dial readily dissolve in molten steel. 

The principal military use of brass was formerly for the manuf of cartridge cases (See Vol 2, pC78-R), but now other materials are used, such as steel, plastics and colloided smokeless proplnts. Another Cu alloy, bronze (Cu 90 Sn 10%) was formerly used for casting gun barrels (Ref 13, p 167), but now steel is used for that purpose. The so-called gilding metal (Cu 90 Zn 10%) has been used as a jacket for lead-alloy bullets (See Vol 2, p B327-R, under Bullets, Metal Jacketed)... 

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