Effect of preheat & post-weld heat treatment on the microstructure and mechanical properties of 6061-T6 aluminum alloy welded sheets

MIG welding is one of the most predominantly techniques in manufactories due to its high automation. However, aluminum alloy welded joints fabricated using often exhibit a reduction mechanical properties. In this paper, an attempt has been made combine preheat and post-weld aging treatment double-pulse (DP-MIG) process produce 6061-T6 sheets with Response surface methodology (RSM) was used study main effect interactive heat parameters including temperature, temperature time on On basis, optimum treat that maximize both strength ductility have determined multi-objective optimization algorithm. Additionally, influence microstructural evolution properties further investigated, by systematic experimental theoretical analysis. The results showed affects grain size precipitation joint, while mainly transformation strengthen phase. Since greater significance for improvement joints, compared other their interactions, indicating strengthening precipitates determines joints.