Abstract: An aluminum alloy member having a satisfactory mechanical strength, an aluminum alloy for casting from which such an aluminum alloy member having a satisfactory mechanical strength can be manufactured, and a method for manufacturing such an aluminum alloy member are provided. In an aspect according to the present disclosure, an aluminum alloy for casting contains, in mass %, Si: 4.0-7.5%, Cu: 1.5-4.0%, Zn: 1.0% or more, and Mg: 0.2-0.8%, in which a remainder of the aluminum alloy for casting consists of Al and unavoidable impurities. Note that a content of Zn may be limited to, in mass %, 1.0% or more and 5.0% or less. Further, a content of Mg may be limited to, in mass %, 0.5% or more and 0.8% or less.

Abstract: The following formula represents a gas cavity distribution of a diameter d of gas cavities in a casting product and the number n of gas cavities, where n is greater than or equal to zero, in vacuum die-casting. A constant A is a function of a flow velocity v of a molten material injected into the cavity at a gate. A constant B is a function of a residual gas amount m in the cavity: In(n)=?Bd+In(A) For cavity analysis, casting conditions including the flow velocity v and the residual gas amount m are input to a computer, and the computer is caused to calculate a gas cavity distribution according to the formula.