Influence of welding parameters on the interface temperature field of TC4 titanium alloys/304 stainless steel friction stir lap joints

The welding parameters optimization of TC4 titanium alloys/304 stainless steel (TC4/304 SS) by friction stir lap welding (FSLW) based on orthogonal test was researched. The results show that when the rotating speed was constant, the area of the high temperature zone and the peak temperature decreased with the increase of the traversing speed; when the traversing speed was constant, the area of the high temperature zone and the peak temperature increased with the increasing rotating speed. Among them, under the condition of low heat input, the interface temperature was about 912 °C, the material at the interface cannot fully react, and there was no formation of a large amount of brittle and hard intermetallic compounds; under the condition of medium heat input, the interface temperature was about 930 °C, this temperature caused a large amount of brittle and hard intermetallic compounds at the interface; under high heat input, the interface temperature was about 975 °C, a large number of intermetallic compounds were not formed at the interface.