Influence of Post Weld Heat Treatment on Microstructure and Mechanical Properties of Friction Stir-Welded 2014Al-T6 Alloy

Abstract

5 mm thick 2014Al-T6 alloy plates were friction stir welded at the welding speeds of 100-400 mm/min and the rotation rates of 400-800 rpm. The influence of post weld artificial aging and T6 treatments on the microstructure and mechanical properties of FSW 2014Al-T6 joints were investigated. It was found that artificial aging did not alter the grain structure but T6 heat treatment caused the abnormal grain growth at the nugget zone. The tensile strength of the joints could not be enhanced by the artificial aging treatment but were improved by the T6 treatment. The effectiveness of T6 treatment is related with the distribution of “S” line.