Honda Motor Co., Ltd.
Aluminum alloy casting having superior high-temperature strength and thermal conductivity, method for manufacturing same, and aluminum alloy casting piston for internal combustion engine

Abstract:

An aluminum alloy casting excellent in high temperature strength and thermal conductivity, a method of producing the same, and an aluminum alloy piston for internal combustion engine using this casting. An aluminum alloy casting having a chemical composition comprising Si: 12.0 to 13.5 mass % Cu: 4.5 to 5.5 mass % Mg: 0.6 to 1.0 mass % Ni: 0.7 to 1.3 mass % Fe: 1.15 to 1.25 mass % Ti: 0.10 to 0.2 mass % P: 0.004 to 0.02 mass % and a balance of Al and unavoidable impurities, wherein in an observed field of view of 0.2 mm.sup.2, the major axis length of the Al--Fe--Si based crystallites is 100 .mu.m or less by average length of 10 crystallites from the largest down. The method for producing the casting comprising casting a melt of aluminum alloy having the above chemical composition at cooling rate of 100.degree. C./sec or more, then performing aging treatment.