Friction Stir Welding Effect on Transverse Rigidity and Sound Transmission Characteristics of AZ31B Magnesium Alloy

AZ31B magnesium alloy was subjected to friction stir welding with various welding parameters. The equivalent Young＇s moduli of the friction stir welded samples and the base material were obtained by the three-point method, and their transverse rigidities were obtained as well. Furthermore, the sound transmission characteristics of those samples were experimentally studied by four-microphone impedance tube method. The experimental results indicate that the transverse rigidities of the friction stir welded samples were only 79%, 83% and 92% of those of the base material, respectively. The sound transmission losses of the processed samples were also lower, which was largely due to the reduction of transverse rigidities induced by the decrease of equivalent Young＇s moduli.