Friction Butt Welding between 6351-T6 Aluminum Alloy and SAE 1020 Steel Assisted by Electromagnetic Induction

Abstract

Friction welding has become interesting in terms of its application. In this context, this paper aimed to evaluate the effect of preheating the conventional friction butt welding between the aluminum alloy AA 6351-T6 and low-carbon steel SAE 1020. An adapted and instrumented drill was applied to make dissimilar joints. Welding was done under two conditions: without preheating and with electromagnetically induced preheating to about 350°C. The welding parameters, with the exception of friction time, were kept constant for both conditions because a new variable was introduced to the process, the preheating temperature. The welding characterisation was analyzed by optical microscopy (OM) and scanning electron microscopy (SEM). Vickers microhardness and traction testing were used to evaluate the welding mechanical strength. The results obtained shown that preheating application decreases by half the total time of the process. The SEM-EDX analysis showed that there was interdiffusion between iron and aluminum. For both welding conditions, the rupture occurred on the bonding interface of the specimens. The mechanical strength of the welds without preheating was of the order of 134 MPa and 113 MPa for welds with preheating.

Key-words:
Friction welding; Dissimilar materials; Electromagnetic induction