Modeling of the Effect of Process Parameters on Tensile Strength of Friction Stir Welded Rare Earth ZE-41 Magnesium Alloy Joints

摘要

The recently developed rare earth containing magnesium alloy ZE-41 is gaining wide spread applications in automobile, aerospace and defense sectors due to its high-quality formability and more strength to weight ratio. Magnesium is normally known as complicated to join material by fusion welding processes owing to defects encountered in fusion welded joints such as inclusions, cracks, porosity, and distortions. Innovative technique, friction stir welding is a capable solid state joining process for successful joining of Mg alloys. The process parameters affecting joint properties of weldments are downward axial force, tool pin geometry, tool rpm and weld speed. In present investigation magnesium alloy friction stir weldments were fabricated with five different tool geometries. Total 31 experiments with 4 factors, 5 levels were conducted as per central composite design matrix. Mathematical model was developed from the data generated by using response surface method. Adequacy for the developed model was checked by means of ANOVA method. Major and interactive influences of welding parameters on tensile behavior are described with the help of graphs for better understanding. It was revealed that the straight cylindrical pin have the highest tensile properties. Mathematical model is useful for the prediction of tensile strength for controlling the weld quality by selecting appropriate process parameters for rare earth containing ZE41 magnesium alloy.