The roughness in the diffusion welding of Ti-6Al-4V alloy

In this study, the authors show that the surface finish plays an important part in diffusion welding of titanium alloys. The welded surface area in titanium alloys increases when the finish roughness R decreases and reaches 100% of the surface when roughness is lower than the titanium auto diffusion X. The ratio X/R defined above seems to play a particular part in weld quality (X = autodiffusion distance of titanium, R = roughness of the surface). In the case of joints between the beta ([beta]) phase, no defect is observed for values superior to one. For values below one, defects become larger and more numerous. Therefore, this parameter seems to express the effects of time, temperature and surface finish.