GRAVITY CASTING PROCESS

PROBLEM TO BE SOLVED: To provide a gravity casting process capable of producing the getter effect of Ti even at a casting temp. lower than the activation temp. (about 750 deg.C) of Ti and impregnating a powder compact with molten metal under gravity. SOLUTION: A compact, which is composed of an Al or Al-base alloy powder, a Ti powder, and 0.05-30 vol.% of a powder of a reactant causing exothermic reaction with Al at a temp. lower than the activation temp. of Ti for dexidizing and denitriding reaction, is impregnated with molten metal or molten alloy under gravity. As the reactant, Ni, Cu, Ag, etc., can be used. Light metals, such as Al and Mg, and light alloys are representatives of the molten metal or alloy to be impregnated. Generally, alloys, such as light alloys, can be produced by this gravity casting process, and particularly, a dispersion-strengthened- type metal matrix composite can be produced by further adding a reinforcement into the compact.