Abstract：According to the joining mechanism of refill friction stir spot welding, reasonable temperature field is the basis of obtaining joints with high quality. Based on the characteristics of refill friction stir spot welding process, a finite element model was established by the finite element analysis software MSC. Marc. The rightness of this model was verified by the temperature measurement experiments, and then the temperature field of 7075-T6 aluminum alloy during welding was investigated by numerical simulation. The results show that at the pre-heating stage, the peak temperature increases rapidly and then slowly with the increase of friction time, and the value reaches a stable one at about 8s. At the welding stage, the peak temperature is located at the center of bottom surface of the sleeve, and the maximum value is obtained when the sleeve is retracted for 1s. Increasing the rotating speed of stirring tool can increase the peak temperature during welding.
2020, 
