Heat Treatment Optimization of 2219 Aluminum Alloy Fabricated by Wire-Arc Additive Manufacturing

Wire-arc additive manufacturing has generated significant interest in the aerospace industry for the fabrication of large aluminum alloy components such as alloy 2219 (Al-6.3Cu). However, its application is limited by the low strength of the deposited parts. In this study, the effect of heat-treatment parameters, including solution temperature, solution time, aging temperature, and aging time, on the mechanical properties was optimized by using the Taguchi method. The results show that the solution temperature is the most influential factor on ultimate tensile strength and yielding strength, while the aging time had the most significant effect on elongation. Thereafter, the best control factor for the maximum response variable was obtained. Microhardness and strength properties were greatly improved after optimized T6 heat treatment. The strengthening mechanism of this additively fabricated Al-6.3Cu alloy was investigated by microstructural analysis.