Vacuum diffusion bonding of Ti2AlNb alloy and TC4 alloy

The Ti2AlNb alloy was joined with TC4 alloy by vacuum diffusion bonding. The relationship between bonding parameters, and joint microstructure and shear strength was investigated. The results indicated that the diffusion of Al, Ti, Nb and V elements across bonding interface led to the formation of three reaction layers: B2/beta layer and alpha(2) layer on the TC4 side, and alpha(2)+B2/beta layer on the Ti2AlNb side. The bonding temperature determined the atomic activity, thus controlling the growth of reaction layers and influencing the shear strength of the joint. When the Ti2AlNb alloy and TC4 alloy were bonded at 950 degrees C for 30 min under 10 MPa, the shear strength of the joint reached the maximum of 467 MPa. The analysis on the fracture morphology showed that the fracture occurred within the B2/beta layer and the fracture model was ductile rupture. Meanwhile, the formation mechanism of the Ti2AlNb/TC4 joint was discussed in depth.

Automated summary

The study explored the vacuum diffusion bonding of Ti2AlNb alloy with TC4 alloy and found that the bonding temperature significantly influences the growth of reaction layers and shear strength of the joint. Under specific conditions, the shear strength of the joint can reach its maximum value.