Welding studies on dissimilar Magnesium alloys zm21 and az31

Abstract

Magnesium is one of the light material, with high strength to weight ratio and good mechanical properties is used as the structural material in structural and automobile industries. As the density of magnesium is three times lower than aluminum it gains its importance in pay load applications in the automotive industries. Welding plays a vital role in joining of materials in the manufacturing industries. And choosing a joining process for two different materials is always being a challenge. The utility of the parent magnesium alloys depends upon the suitable welding process with minimum metallurgical changes to posses good weld strength efficiency. The welding of similar magnesium alloys are plenty however the dissimilar welding of magnesium alloys has not attempt by the many researchers due to difficulty of formation of intermetallic compounds in the interface of the welds and metallurgical disruptions that ruin the performance of the welds. newlineIn this thesis both fusion and solid state welding process is considered for joining dissimilar magnesium alloy joint. The magnesium alloys considered in this investigation are AZ31B and ZM21. Dissimilar welding of Magnesium alloys of AZ 31 B and ZM21 using Friction stir welding and TIG welding process is the novelty of the research. The process parameter for both the FSW and TIG welding process is optimized using Taguchi L9 orthogonal design. The input process parameter considered for FSW is the rotational speed, tool shape and axial load, while the welding speed is kept constant. The input process parameter considered for TIG welding are current, frequency and welding speed, while the voltage and flow of shielding gas is kept constant. The tensile strength of the joint is the response considered for both the FSW and TIG welding process. newline