Experimental investigation of microstructural and mechanical properties over friction stirred welded joints of aa 7075 aa 8011 mmc and aisi 409m

Abstract

It is difficult to join dissimilar materials owing to the differences in the mechanical aspects and the metallurgical differences Also due to differences in thermal conductivity melting and boiling point relative heating of the joint region becomes difficult The softer material tends to melt sooner while the other material is still solid This causes lots of defects in the joint regions So conventional welding become helpless and search for better joining techniques resulted in using solid state joining techniques Friction Stir Welding FSW is a relatively new solid state material joining methodology which is being largely used in welding industries In thismethod welding is executed by using thermo-mechanical deformation usingfrictional heat to stir the welding region to increase the temperature above recrystallization temperature As melting point of bas material is not reached in this method enhanced mechanical aspects better tensile strength and refined microstructures are obtained Compared to fusion welding techniques this method consumes lesser energy Also shielding gases and filler rods are not necessary in FSW which reduces the cost of material joining. newline