Effect of Zr content on formability, microstructure and mechanical properties of selective laser melted Zr modified Al-4.24Cu-1.97Mg-0.56Mn alloys

Abstract The effect of Zr content of SLM processed (SLMed) Zr modified Al-4.24Cu-1.97Mg-0.56Mn alloys on the formability, microstructure and mechanical properties has been investigated. It is observed that, with the addition of Zr increaseing, the tendency of density is consistence with the tendency of thermal conductivity and solidification temperature range (STR). The addition of Zr promotes the expansion of processing window as well as the transformation of grain type from columnar to equiaxed. Al3Zr and ZrO particles act as heterogenous nucleation for solidification processing, resulting in a very fine microstructure, low cracking sensitivity and good performance. The alloy tailored by adding 2 wt% Zr showed the maximum processing window and ultimate tensile strength (UTS = 493.3 MPa). The effect of Al3Zr on grain refinement, inhibition of cracks and improvement of mechanical properties have been discussed.