Effect of friction pressure on joining phenomena of friction welds between pure titanium and pure copper

This paper describes the effect of friction pressure on the joining phenomena of friction welds between pure titanium (P-Ti) and pure copper (OFC). When the joint was made at a friction pressure of 60 MPa or lower, the OFC side had deformation from the contact of both weld faying surfaces. Then the joint had generated sparkle from the P-Ti side with increased friction time. The peripheral portion of the P-Ti side had large deformation and was intensely upset when the joint had sparkle. On the other hand, the joint did not have sparkle on the P-Ti side when it was made at a friction pressure of 75 MPa or higher. The deformation of the OFC side was large and was intensely upset, although the P-Ti side was hardly deformed. The joining phenomena had dissimilarity because the difference of the yield stress for each material depended on the temperature in the friction process.