Vacuum diffusion bonding of Ti2AlNb alloy and TC4 alloy
(1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. College of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045, China)
2. College of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045, China)
Abstract: 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/β layer and α2 layer on the TC4 side, and α2+B2/β 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 °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/β layer and the fracture model was ductile rupture. Meanwhile, the formation mechanism of the Ti2AlNb/TC4 joint was discussed in depth.
Key words: Ti2AlNb alloy; TC4 alloy; diffusion bonding; interfacial reaction; shear strength; formation mechanism