Effects of Bonding Temperature on Microstructure and Properties of TA2 Transient Liquid Phase Bonded Titanium Plate Joints

Titanium TA2 plates were joined by transient liquid phase bonding at different bonding temperatures in argon atmosphere, using Cu-Ni-Sn-P amorphous foils as interlayer. Influence of bonding temperature on the microstructure, micro-hardness and shear strength of the joints were investigated by an optical microscope, a micro-hardness tester and a material tester. The results show that the isothermal solidification of the liquid interlayer did not complete at the bonding temperature lower than 840 ℃, and the remaining interlayer could be observed. Atomic diffusion speeded up and the remaining interlayer reduced gradually with the increase of bonding temperature; the microstructure of the joints were all solid solution at 870 ℃. The joints had the highest shear strength around 180 MPa when the bonding temperature was 850 ℃.