Patent ID: 11008640

Abstract:
An aluminum alloy for casting, made of an Al—Si—Cu—Mg alloy which consists of specific amounts of Si, Cu, and Mg, in addition to specifically desired amounts of titanium, phosphorus, boron, and optional additional chemical elements sodium and strontium, with the balance of the aluminum alloy comprising aluminum and any impurities. When a content of phosphorus is defined as X mass %, the content of phosphorus, a content of Y mass % of sodium, and a content of Z mass % of strontium satisfy the following relationships: 0.45Y+0.24Z+0.003≤X≤0.45Y+0.24Z+0.01; 0≤Y≤0.01; and 0≤Z≤0.03. The aluminum alloy ensures surface smoothness of a cast article by specifying the phosphorus content. This minimizes a surface segregation layer, even in production of a cast article using a molten metal containing a eutectic structure modifier such as sodium.