Inoculation of heterogeneous nucleation site on microstructure and mechanical properties of A7003 aluminum alloy manufactured by wire-type directed energy deposition

In this study, the effects of Al 3 (Ti 1-x Zr x ) heterogeneous nucleation site particles on the formability, microstructure and mechanical properties of A7003 (Al-Zn-Mg) alloy samples manufactured by the wire-type directed energy deposition (DED) method were studied. The lattice matching between the Al 3 (Ti 1-x Zr x ) heterogeneous nucleation site particles and the primary crystal of A7003 Al alloy at solidification temperature is found to be good. The formability of wire-type DED can be improved and the occurrence of defects can be suppressed by addition of the heterogeneous nucleation site particles. The grain size and aspect ratio of the samples manufactured using the inoculated wire were found to be smaller than those of the uninoculated wire. It is also found that samples manufactured using uninoculated wire without heterogeneous nucleation site particles (uninoculated samples) show strong anisotropy and position dependence in mechanical properties. However, those containing heterogeneous nucleation site particles (inoculated samples) have higher mechanical properties without anisotropy and position dependence. It is concluded that the parts of the A7003 Al alloy with higher mechanical properties can be additively manufactured by inoculation of Al 3 (Ti 1-x Zr x ) heterogeneous nucleation site particles.