Impression creep behavior of different Zones in zm21 and ze41 magnesium alloy Friction stir welds

Abstract

Magnesium alloys have gained exponential importance in the last two decades across various applications like automotive, electronics, defense, aerospace, and biomedical applications. Magnesium alloys have offer high specific strength, good castability, machinability, and biocompatibility. Their applications are predicted to grow and widen further in the near future. However, their application is limited because of the drawbacks like poor corrosion and high-temperature creep resistance. To widen the domain of their application, continuous efforts are being made to develop newer magnesium alloys or improve the mechanical properties, especially the elevated temperature creep resistance of the existing magnesium alloys. Among the magnesium alloys, the Mg-Al family of alloys is one of the most studied and used alloy families. Presence of aluminum has been found to aid formability but reduces the elevated temperature creep resistance of Mg alloys as it forms thermally less stable 13-(Mg17Al12) phase and hence Mg alloys without Al are preferred to achieve elevated temperature creep resistance. Mg-Zn alloys show relatively better creep resistance, ductility and mechanical properties especially when a ternary addition of rare-earth element is added. newlineIn the present study, a wrought alloy ZM21, a cast alloy ZE41 belonging to Mg-Zn family of alloys and their friction stir welds, are chosen for elevated temperature creep study. Wrought alloys possess relatively homogeneous microstructure, better mechanical properties and lesser internal defects compared to cast alloys. Mg-Zn alloys are not studied as exhaustively as Mg-Al family of alloys. There are few studies on Mg-Zn alloys but not on ZM21, which is considered to be a low-cost extrusion alloy newline newline