Processing, experimental characterization and thermal analysis for friction stir welded joint of 2219Al alloy

Present study aimed at thermal modelling and numerical analysis of dynamic heat flow behaviour, for friction stir welded (FSW) joint of 2219Al alloy, further experimentally correlated with microstructural evolution and microhardness profile through different weld zones. FSW was performed on cast 2219Al alloy, with varying process parameters of welding and rotational speed of the tool, and transient temperatures measured at different distances from weld line. From microstructural analysis, three different heat affected weld zones having separate grain morphologies were identified, namely Weld Nugget Zone (WNZ), Thermo-Mechanical Affected Zone (TMAZ) and Heat Affected Zone (HAZ). Vickers microhardness was evaluated at varying distances from weld line, through different weld zones. To investigate transient temperature profiles over the welded plate, a 3-D Finite Element (FE) thermal model was developed, incorporating volumetric heat source as heat generation. Transient temperature profiles computed from FEM analysis, were successfully compared and validated with experimental results, with fairly good accuracy within 4.86 %. Individual influences of welding parameters, on transient temperature profile, weld zones, microstructural and mechanical property were investigated, to optimise and achieve desired weld quality. Present study established structure-property correlation, along with thermal analysis, to validate and optimise the potential application of FSW on 2219Al alloy.