Abstract: To provide a wear resistance comparable with that of the conventional A390 series aluminum alloys, a reduced attacking to a sliding counterpart, and an improved machinability, a wear-resistant cast aluminum alloy comprises: a chemical composition consisting, in weight percentage of: 14.0-16.0 Si, 2.0-5.0 Cu, 0.1-1.0 Mg, 0.3-0.8 Mn, 0.1-0.3 Cr, 0.01-0.20 Ti, 0.003-0.02 P, 1. 5 or less Fe, and the balance of Al and unavoidable impurities in which the Ca content is limited to not more than 0.005; and a microstructure in which a primary Si crystal and Al-Si-Fe-MnCr-based intermetallic compounds are dispersed in the form of a crystallized particle having a diameter of from 5 to 30 gm. A process of producing a wear-resistant cast aluminum alloy includes casting a melt of the alloy composition at a cooling rate of from 50.degree. to 200.degree. C./sec.

Abstract: An aluminum alloy for forging comprising from 2.0 to 3.3% by weight of Si, from 0.2 to 0.6% by weight of Mg, from 0.01 to 0.1% by weight of Ti, from 0.0001 to 0.01% by weight of B, up to 0.15% by weight of Fe, one element or at least two elements selected from the group consisting of 0.001 to 0.01% by weight of Na, 0.001 to 0.05% by weight of Sr, 0.05 to 0.15% by weight of Sb and 0.0005 to 0.01% by weight of Ca, up to 0.001% by weight of P, the P/Ca weight ratio being up to 1.0, and the remainder Al, eutectic Si contained in the cast structure of said aluminum alloy having an average particle size of up to 20 .mu.m.