Effects of Post-Weld Heat Treatment on Microstructure and Mechanical Properties of Al-12.7Si-0.7Mg Alloy Welded Joints by GMAW

In this study,3-mm-thick hot-extruded plates of Al-12.7Si-0.7Mg alloy were used to fabricate the joints welded by gas metal arc welding.Effects of the post-weld heat treatment include solid solution treatment,water quenching,and artificial aging treatment on the microstructure,and mechanical properties of the weld joints have been investigated.Results showed that the welded joints after solid solution and artificial aging exhibited the increases in yield strength of166 MPa and ultimate tensile strength of 148 MPa,respectively.Based on the microstructural observations,the associated mechanisms were discussed.