Aluminum alloy casting having high strength and high toughness and process for producing the same

摘要

Disclosed are an aluminum alloy casting having a high strength and a high toughness, and a production process for the same. The aluminum alloy casting comprises silicon (Si) in an amount of 2.5 to 4.4% by weight, copper (Cu) in an amount of 1.5 to 2.5% by weight, magnesium (Mg) in an amount of 0.2 to 0.5% by weight and the balance of aluminum (Al), and a matrix thereof includes a dendrite which has a size of 30 micrometers or less. Since the Si addition amount is suppressed as less as possible and since the size of the dendrite is micro-fined in the aluminum alloy casting, the toughness is improved remarkably. Further, since the Cu and Mg are added in the predetermined addition amounts, the strength is enhanced in the aluminum alloy casting. In addition, a solution treatment which is employed in the production process can further enhance the strength of the aluminum alloy casting.