Investigations on friction stir welding of cast aluminium alloys

Abstract

The usage of cast aluminium alloys in automotive and aerospace newlineapplications is ever increasing due to their light weight and castability It is newlinenecessary to weld aluminium castings to themselves or to wrought alloys for newlinevarious applications These alloys are not easily weldable by conventional newlinefusion welding techniques because the quality of the welded joint is newlinedeteriorated due to the presence of porosity hot cracking and distortion newlineFriction Stir Welding FSW process is an emerging solid state joining newlineprocess in which the material that is being welded does not melt and recast newlineFSW creates the weld joint without bulk melting In addition the extensive newlinethermomechanical deformation induces dynamic recrystallization and newlinerecovery that refine the microstructure of the stir region Therefore welds newlinemade by FSW are shown to have much improved mechanical properties than newlinethe corresponding fusion welds newline newline