Patent ID: 8721811

Claim:
A method of casting an aluminum alloy into a cast product having an improved critical fracture strain, the method comprising: providing a melt having an alloy comprising: about 6.0 wt % to about 7.8 wt % Si; about 0.10 wt % to about 0.18 wt % Mg; less than or equal to about 0.35 wt % Cu; less than or equal to about 0.6 wt % Mn; less than or equal to about 0.15 wt % Fe; and, a balance of aluminum and impurities; casting the melt into a cast body; and, heat treating the cast body; wherein, the processing comprises a solution heating at 450° C. to 550° C. for about a ½ hour to about 6 hours; quenching, and aging at a temperature of about 150° C. to about 250° C. for about ½ hour to about 10 hours; and, the cast body has a critical fracture strain of at least about 10%.