Patent ID: 7921901
Filing Date: 2011-04-12
Classification: B22D

Abstract:
1. A method of die casting an aluminum alloy article of predetermined composition and having an internal cylindrical wall surface, the cylindrical wall surface having at least one predetermined internal cross-section dimension and a height, the method comprising: providing a die casting tool having a cylindrical surface portion, the cylindrical surface portion having a height for forming the cylindrical surface of the article and a cross-section smaller than the cross-section of the cylindrical wall surface; placing a hollow cylindrical sleeve liner on the cylinder surface portion of the tool, the liner having a thickness, a height, a cross-section shape, and an outer surface for defining the internal cylindrical wall surface of the article, the hollow liner being formed of an aluminum alloy; casting a melt of the aluminum alloy of the article against the outer surface of the sleeve liner, the melt solidifying against the liner surface and bonding to it, the thickness of the sleeve liner being predetermined to resist melting or distortion by the cast aluminum alloy before the cast alloy solidifies; removing the cast article and bonded cylindrical sleeve liner from the die casting tool; and machining the entire cylindrical sleeve liner from the internal surface of the cast article to form the internal cylindrical surface of the article.