*DIE CASTING ALLOYS

*IMPORTANCE(GOVERNING FACTORS FOR SELECTION)

Cost

Die life

Physical properties flowability, corrosion resistance, wear resistance, etc.

Mechanical properties tensile strength, hardness, elongation, impact strength, etc.

Thermo-phy. properties thermal expansion, melting range, density, sp. heat capacity, etc.

*COSTAluminium and Magnesium are abundant but their extraction is a long process making them costly.Copper and Zinc are less abundant and are less costly to extract. But their yield from ore is less than 1% and in future we may face problems in obtaining them.

*DIE LIFECold Chamber Process There is less time exposure of the melt to the plunger walls or the plunger. This is particularly uses metals such as Aluminum and Copper that tend to easily alloy with Iron at the higher temperatures.Hot Chamber Process The metals used for this process are of low melting point and high fluidity such as Tin, Magnesium, Zinc, and Lead that tend not to alloy easily with steel at their melt temperatures.

*Alloys used in die casting have freezing ranges, from a few degrees for the zinc alloys with 4% aluminum to over a hundred degrees for magnesium alloys.

AlloysLiquidousSolidousFreezing RangeZinc alloy (4.1% AI)3873825Aluminum-silicon alloys 8%Si60557728 10%Si5905771311%Si585577812%Si5825775Aluminum-silicon copper alloy(10.5% Si, 3.5% Cu)58052060

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Aluminum-magnesium alloys5%Mg635590457,5% Mg6255606510.0% Mg61052585Magnesium alloy (9% AI)596468128Brass (60% Cu, 39.5% Zn, 0.5% AI)91090010Aluminum bronze(89% Cu, 10% AI, 1% Fe)1053104013Lead alloy (5% Sb)31027040