Enhancement of joint strength in friction stir lap welding between AA6061 and AISI 304 by adding diffusive coating agents

Abstract

This study focuses on the usage of fly-ash and Al-12%Si as diffusive coating materials over AISI 304 steel welded with AA 6061 in friction stir welding process to improve the joint quality. Various mechanical and metallurgical studies have been carried out to evaluate the characteristics of the weld, and investigate and compare the effect of the two coating materials. Formation of intermetallic reaction layer has been found to be an influential parameter affecting the joint quality. Aluminium-rich intermetallic reaction layer has been observed in the bare welds, whereas the coated samples have been found to have ferrous-rich intermetallic reaction layer.