US 7,347,905 B1
	Aluminum-silicon alloy having reduced microporosity and method for casting the same
Raymond J. Donahue, Fond du Lac, Wis. (US); Terrance M. Cleary, Fond du Lac, Wis. (US); and Kevin R. Anderson, Fond du Lac, Wis. (US)
Assigned to Brunswick Corporation, Lake Forest, Ill. (US)
Filed on Jul. 05, 2005, as Appl. No. 11/174,764.
Application 11/174764 is a continuation in part of application No. 10/429098, filed on May 02, 2003, granted, now 6,923,935.
Int. Cl. C22C 21/04 (2006.01)

U.S. Cl. 148—415  [420/546; 420/549; 420/534]

7 Claims

1. An aluminum silicon lost foam cast alloy consisting essentially of: 9.0-9.5% by weight silicon, 0.05-0.300% by weight strontium, 0.20% by weight maximum iron, 0.05-0.25% by weight copper, 0.05-0.50% by weight manganese, 0.05-0.60% by weight magnesium, 3.0% by weight maximum zinc, and the balance aluminum, wherein the alloy is cast with a lost foam casting process that applies approximately 10 ATM of pressure during solidification of the alloy to substantially completely suppress the formation of hydrogen porosity and substantially decrease the incidence of porosity defects and narrow the solidification range in comparison to conventional lost foam cast aluminum silicon alloys.