The effect of diffusion welding process parameters on the microstructure

mechanical properties and deformation of Ti

2

AlNb alloy welded joints was studied. The results show that when the welding temperature

pressure

and holding time are low

the weld line of Ti

2

AlNb diffusion welding joint is distinct

and the mechanical properties are inferior. With the increase of welding temperature

pressure

and holding time

the size of the newly formed equiaxed α

2

phase in the welding zone enlarges

the weld line gradually becomes indistinct

and the mechanical properties

the welding d

eformation rate of the Ti

2

AlNb diffusion welded joint increase. Based on the microstructure of the weld interface

welding deformation rate

and mechanical properties

the optimal Ti

2

AlNb diffusion welding process parameters are 960 ℃

5 MPa

and 120 min. Under this condition

the welding deformation rate is 5.4%. The Ti

2

AlNb diffusion welded joint consists of B

2

phase matrix

some coarse lath-like α

2

phase

some equiaxed granular α

2

phase and some O phase distributed within the B

2

phase matrix. The tensile strength reaches 891 MPa at room temperature and 464 MPa at 700 ℃.