Heat-resistant aluminum alloy having high fatigue strength

摘要

The aluminum alloy of the invention has excellent fatigue strength, high rigidity, and low thermal expansion coefficient, and is suitable for rotating components such as conrods in an internal combustion engine. The aluminum alloy is an Al-Si alloy which contains 7.0-12.0% wt. Si, 3.0-6.0 % wt. Cu, 0.20-1.0% wt. Mg, 0.30-1.5% wt. Mn, 0.40-2.0% wt. Ti+V, 0.05-0.5% wt. Zr, and the remainder Al and being inevitable impurities and which contains a dispersed intermetallic compound of average particle size of 0.5 m or less and containing Ti, V, and Zr. The alloy is preferably manufactured by the rapidly solidifying powder metallurgy process, or by the spray-forming process. By selecting a work-hardening exponent of 0.20 or less, the thread rolling workability is improved.