High strength and toughness aluminum alloy casting by high-pressure casting method and method of manufacturing same

摘要

An aluminum alloy cast molding produced by a high-pressure casting method, and having a composition containing Si in an amount of 0.6 to 1.0% by weight (which will be hereinafter simply referred to as %), Cu in an amount of 0.6 to 1.2%, Mg in an amount of 0.8 to 1.2%, Zn in an amount of 0.4 to 1.2%, Ti in an amount of 0.01 to 0.20%, and B in an amount of 0.002 to 0.015%, with the remainder being aluminum and inevitable impurities. The maximum dendrite cell size of the metal structure of the aluminum alloy casting is limited to 60 mu m or less. The present invention also provides a method of manufacturing an aluminum alloy casting by high-pressure casting, which manufacturing method includes the steps of charging a mold with a molten aluminum alloy having the above alloy composition, and subsequently solidifying the charged molten metal under pressures as high as 500 Kgf/cm2 or above so that the maximum dendrite cell size of the metal structure of the aluminum alloy casting is limited to 60 mu m or less.