Solidification structure transformation and strengthening of wire and arc additively manufactured Al-Cu alloy single wall multi-layered deposits

In the present study, Al-Cu WAAM deposits were fabricated under three conditions: powder free, with TiB 2 and TiC powder at the interlayer. After deposition, the deposits were solutionized at 530 °C for 90 min and artificially aged at 180 °C for 3 h. The effect of powder particle addition and post-processing heat treatment (PPHT) were investigated. Powder free specimens show non-uniform structures throughout the deposit. TiB 2 and TiC powders refined the non-uniform solidification structure and diminished it to an equiaxed structure. PPHT promotes precipitation of secondary phases, enhancing mechanical characteristics of the depsoits. As-deposited specimens had Ultimate Tensile Strength (UTS) values of 263 MPa (powder free), 322 MPa (TiB 2 ), and 314 MPa (TiC), whereas PPHT specimens had 465, 487, and 482 MPa.