Feasibility Study on Aluminum Alloys and A441 AISI Steel Joints by Friction Stir Welding

In this paper, welding feasibility between AA1100, AA5050 and AA6082 aluminum alloys and A441 AISI steel by friction stir welding has been studied. For this purpose, numerical simulation of heat generation, material flow, defect formation, tensile and micro-hardness test were investigated on all joints. The numerical simulation results indicates that the maximum heat generated in AA6082 and AA441 AISI joint and heat distribution on AA1100 surface is more than other joint planes. The optical microscope images revealed that the stir zone in AA1100-A441 AISI has linear shape, whereas the other joints have elliptical shape. The AA1100-A441 AISI stir zone made defect free, meanwhile small tunnel were formed in the stir zone of AA6082, AA5050 and A441 AISI joints. The failure position on the tensile specimens was located at the aluminum side on all joints. The tensile test shows that the uppermost joint efficacy was allocated to AA6082 - A441 AISI. The micro-hardness tests indicates that the stir zone have superior hardness with respect to the other weld areas. This phenomenon is the consequence of distributed steel fragments in stir zone and formation of intermetallic compounds in Al/St interfaces.