ASTM B1033: new specification for the ZAC75 zinc–aluminium–copper die-casting alloy
ASTM International has approved standard B1033-26, which sets chemical composition requirements for ZAC75 alloy ingots intended for die casting. According to ASTM the alloy offers higher strength, hardness and creep resistance than conventional zinc die-casting alloys.
- The specification covers commercial zinc–aluminium–copper alloy in ingot form for remelting into pressure die castings, foundry castings and continuous cast bar stock; the requirements are given in Table 1 of the standard.
- It was developed by subcommittee B02.04 of ASTM committee B02 on nonferrous metals and alloys; the standard has 3 pages and its values are stated in inch-pound units.
- The alloy is close to the zinc–aluminium–copper eutectic composition, which according to ASTM gives good castability while keeping the advantages of zinc die casting: high production rates, lower processing temperatures and longer die life.
- ASTM notes that the standard will give die casters, laboratories, procurement organisations and regulatory bodies a common reference for material verification and quality assurance.