Effects of Holding Time on Microstructure and Properties of TLP Diffusion Bonded TA2 Pure Titanium Joint

With Cu-Ni-Sn-P amorphous alloy as interlayer material, TA2 pure titanium was welded using transient liquid phase (TLP) diffusion bonding and the effects of holding time on the microstructures and mechanical properties of the joint were studied. The results show that the joint seam consisted of a residual layer, an isothermal solidification layer and an interfacial diffusion layer. With the increase of holding time, the residual layer thickness decreased and the diffusion layer was broadened. After holding for 5 min, the joint mainly consisted of feather-like diffusion layer with the width of 25 μm. The shear strength of the joint first increased and then decreased with the holding time increase and reached the largest value of 180 MPa at the holding time of 3 min. The shear fracture mode was a mixed ductile and brittle fracture.