Multi response optimization of parameters through generation of quadratic regression models for joining of mg alloys by friction stir welding

Abstract

Multi response optimization of parameters through generation of quadratic regression models for joining of mg alloys by friction stir welding Among the lightweight category materials, alloys of Magnesium, especially AZ80A, AZ91C mg alloys, were found to be employed for an ample range of aerospace, automobile, and shipbuilding sectors, in view of their excellent specific strength, recyclability, higher values of specific stiffness, outstanding machinability, lower density values etc. But at the same time, being a hexagonally closed packed structured metal, the slip structures of alloys of Mg are constrained in regard to plastic deformation. Therefore, improving the ductility of Mg alloys (especially AZ80A and AZ91C) is an essential criterion for increasing the usage and applicability of these alloys to various industrial sectors. It is a proven fact that the ductility and strength of the metals (possessing HCP structure) can be enhanced through the refinement of their grain structures. It is foreseen through various research works that, the state of superplasticity will occur in these alloys if their grain size is reduced drastically. AZ80A and AZ91C are very common and popular Mg alloys, which are being employed in nearly 85 91% of all the Mg components, due to its unique and excellent properties, low cost, high levels of resistance to corrosion, etc. At the same time, its lower values of elongation property (arising due to the existence of coarse grains in its microstructure) have to be improved to make it be applicable to various industrial sectors. With the objective of widening the application areas of this AZ91C and AZ80A Mg alloys to several industrial sectors, various research initiatives have been carried out broadly, primarily focussing on the improvement of the ductility of the AZ80A and AZ91C Magnesium alloys through refinement of their grain structures.Compared to various plastic deformation improvement techniques, FSW (Friction Stir Welding) was proven to be very much effective in fabricating high