Synergetic effects of Cr, Zr, Mg and Zn microalloying on microstructure and mechanical behavior of AlSi9Cu3 alloy

The effect of the alloy elements on the microstructure and the mechanical properties of an AlSi9Cu3 (Fe) secondary alloy is analysed. The additives involved include Zn, Mg, Cr, Zr and TiB, which were added in small amounts. The experimental alloys were heat treated to obtain a T6 condition. The hardness peak was observed in the samples aged for 3 h in the alloy studied obtained by adding 1%Zn-1%Mg-0,2%Cr-0,2% Zr. This maximum value represents a 64% increase in hardness compared to the base alloy, and with a 37% reduction in aging time.Peer ReviewedPostprint (published version