Aging response of AA7075 + TiC fabricated by wire + laser directed energy deposition

Abstract

The objective of this study is to evaluate laser directed energy deposition of AA7075 wire with TiC nanoparticles to promote grain refinement and eliminate cracking. Microstructure analysis showed the presence of a nonuniform distribution of TiC clusters and the formation of a mix of equiaxed and columnar grains. The effect of direct and traditional T6 aging heat treatments was studied, and it was shown that the direct aged sample heated for 5 hrs at 120 °C was of comparable hardness to the T6 heat-treated sample (115 HV0.5). However, no age hardening conditions matched the hardness of wrought AA7075, due to evaporation of Zn and Mg during printing.