INVESTIGATION ON WELDABILITY OF DISSIMILAR FRICTION STIR WELDED AA5052 AND SS304 ALLOYS

Friction stir welding is considered an ideal and better technique to weld dissimilar materials when compared to conventional welding methods. However, the main challenges faced during friction stir welding of different materials are defects and intermetallic compounds formed at the interfacial region. In this context, dissimilar friction stir welding of AA5052 and SS304 has been carried out in butt and lap configurations with suitable Taguchi’s orthogonal array at various tool rotational speeds, welding speeds, penetration depths and tilt angles to obtain a sound joint without defects. Friction stir butt welding was not successful in achieving a defect free joint. Friction stir lap welding with aluminium as the top plate achieved a defect-free joint when the experiments were conducted at a tool tilt angle of 2.5. Microstructural analysis of the defect-free welds revealed that the intermetallic layer's thickness had influenced the joint strength.