ALUMINUM ALLOY CASTING HAVING SUPERIOR HIGH-TEMPERATURE STRENGTH AND THERMAL CONDUCTIVITY, METHOD FOR MANUFACTURING SAME, AND ALUMINUM ALLOY CASTING PISTON FOR INTERNAL COMBUSTION ENGINE

摘要

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 use using this casting are provided. 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 2 , the major axis length of the Al-Fe-Si based crystallites is 100 µm or less in terms of the average length of 10 crystallites from the largest down. An aluminum alloy piston for internal combustion engine use comprised of the same. A method for producing an aluminum alloy casting comprising casting a melt of aluminum alloy having the above chemical composition by a cooling rate of 100°C/sec or more, then performing aging treatment.