Pressure casting method with recoverable melt out core

摘要

A zinc alloy melt-out core comprises from 0.75% to 3% Cu, from 0% to 0.3% Ni, from 0% to 0.5% Al, and balance Zn. The zinc alloy melt-out core is used in pressure casting processes for producing an aluminum article having a hollow. The zinc alloy core has a shape-imparting outer surface. In the pressure casting process, the zinc alloy core preserves a space corresponding to the hollow. The zinc alloy core has improved hot strength and thus maintains its integrity during the pressure casting process, inhibiting seepage of the core material into the aluminum cast article. Preferred zinc alloy melt-out cores further comprise an outer coating of insulating material selected from the group consisting of mica, graphite, ceramics and combinations thereof.