Microstructure and properties of electron beam welded joints of dissimilar high temperature titanium alloys

High temperature titanium alloy Ti60 plate and Ti700sr casting were welded by vacuum electron beam welding machine, and the microstructure and mechanical properties of the joint were studied. The results show that the high temperature titanium alloy Ti60 plate and Ti700sr casting have good weldability by electron beam welding, and high quality joint can be obtained. The welding seam in the joint is fine acicular martensite, and there are stacking faults and twins infusion zone of Ti700sr side. The α phasein the HAZ of Ti700sr grow a lot compared with the α phase in the base metal. There are rich rare earth Nd precipitates in the fusion zone and heat affected zone on the Ti60 side. The microhardness of the weld metal is similar to that of Ti60 and Ti700sr, which is about 360 HV. The highest hardness occurs in the heat affected zone of Ti60 side, and the maximum hardness reaches 418 HV. The tensile properties of the joints at 600 and 650 ℃ are 695 and 587 MPa respectively. Copyright © 2020 Transactions of the China Welding Institution. All rights reserved.