Effect of weld parameters on joint quality in friction stir welding of Mg alloy to DP steel dissimilar materials

Dissimilar material joining between magnesium (AZ31B) alloy and dual-phase steel (DP600) was achieved using the friction stir welding (FSW) process. The present work aimed at studying effect of tool rotational speed on microstructure mechanical properties dissimilar joints. joints were fabricated speeds 800 1600 rpm with weld 50, 100, 150 mm/min, respectively. plunge depth 0.2 mm tilt angle 2° kept constant during welding. Temperature rise variation torque process recorded. Optical microscopy, scanning electron microscopy equipped energy dispersive spectroscopy (EDS), X-ray diffraction studies carried out to understand microstructural changes, interface joints, fracture morphology, formation intermetallic compounds FSW. Maximum joint efficiency 76.4% respect AZ31B. observation revealed finer grains zone for all parameters because dynamic recrystallization. metallurgical bonding materials observed due compounds. sawtooth profile indicated interlocking AZ31B Mg DP600 steel. Though Mg–DP600 combination is highly immiscible, attempts have successfully created joining, where one substrates provides lightweight while other strength.