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A creep resistant zinc-aluminum hot chamber die casting alloy has been developed to operate at service temperatures up to 120°C. The Zn-Al-Ni alloy consists of a ZA-8 matrix reinforced with 10 vol% of fine NiAl3 intermetallic particles. The alloy was hot chamber die cast with good distribution of the reinforcement in cast parts and little wear observed on the machine plunger assembly. Creep tests at 120°C indicated significant improvement of creep strength over conventional zinc die casting alloys. The creep mechanism appears to be related to the resistance of the strong, stable intermetallic particles to plastic flow of the matrix material.

The addition of nickel-coated graphite to silicon carbide particulate reinforced aluminium alloys imparts unique properties to the new composite GrA-Ni™; the graphite makes it useful in high wear applications where it behaves analogously to flake graphite in grey cast iron. Graphite improves scuffing resistance and significantly increases the critical load at which the transition from mild wear to severe wear occurs. The graphitic silicon carbide MMC has better machinability and can be machined at higher metal removal rates than other existing SiC reinforced composites. Fatigue life was determined to be similar to A356-15% SiC composite.