Modification of mechanical properties of friction stir welded AM60 magnesium alloy with changing rotational speed and addition of nano alumina particles

In this study mechanical properties of friction stir welded AM60 magnesium alloy in existence and lacking of alumina nanoparticles were examined. Microscopical analysis revealed peak condition could be made in 1200 rpm rotational speed, not only in the absence of reinforcing alumina nanoparticles but also in the presence of them. Adverse effects of higher strains in lowering grain size and higher temperatures in grain growth should be considered. In the existence of alumina nanoparticles in the matrix some areas of low content aluminum formed besides of high aluminum content of intermetallic compounds regions. Higher hardness and ultimate tensile strength achieved in optimum 1200 rpm rotational speed not only with alumina nanoparticles but also in the absence of alumina nanoparticles condition. Higher stresses and therefore lower agglomerated alumina nanoparticles resulted with increasing rotational speed. With alumina nanoparticles in matrix, lower grain size, higher hardness and higher ultimate tensile strength was attained.