Study on the Surface Integrity of TC4 "I" Type Component by Robot 2 Laser Welding

Aiming to study the surface integrity of the "I" type component in laser welding, the "I" type constitutive mechanics model of titanium alloy TC4 was constructed in this study. The preliminary laser welding test was completed and the best laser welding parameters were optimized. The microscopic surface morphology of titanium alloy TC4 during "initial welding stage"(IWS), "middle welding stage"(MWS) and "tail welding stage"(TWS) was studied, and the temperature and stress simulation analysis were carried out. The results show that low roughness and high error will appear in the IWS and TWS, and it is relatively stable in the MWS. The difference between the maximum and minimum values of laser welding surface roughness and error of titanium alloy TC4 "I" type component is 6.3 µm and 0.53 mm, respectively. The center temperature of laser welding heat source can reach about 2850◦C, and the temperature of weld center rises and drops rapidly. It taken about 2 s to drop from 2850◦C to 450◦C. When the longitudinal residual stress is maintained at about 780MPa, it reached a stable state. The transverse residual stress is −130MPa.