Thermo-physical simulation of deformation behavior and microstructure evolution for linear friction welding of near-β titanium alloy
(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. Aeronautical Key Laboratory for Welding and Joining Technologies, AVIC Manufacturing Technology Institute, Beijing 100024, China;
3. Mechanical Engineering Department, University of West Attica, Athens, 12241, Greece)
2. Aeronautical Key Laboratory for Welding and Joining Technologies, AVIC Manufacturing Technology Institute, Beijing 100024, China;
3. Mechanical Engineering Department, University of West Attica, Athens, 12241, Greece)
Abstract: In order to better understand the interface bonding behavior of linear friction welding (LFW) of a near-β titanium alloy, the thermo-physical simulation for deformation behavior and microstructure evolution of a near-β TB2 titanium alloy was carried out by using hot compression tests with specially designed hat-shaped specimens under different compression displacements, temperatures and strain rates which were decoupled in the simulation process. The results show that the peak shear stress in bonding zone (BZ) during hot compression increases with decreasing deformation temperature and increasing strain rate, and the width of BZ decreases with increasing deformation temperature and strain rate. The margin of BZ has largely deformed grains, and the center of BZ has fine equaxied recrystallized grains. The mechanism of the joint is continuous dynamic recrystallization (CDRX) and the degree of CDRX in BZ increases with increasing compression displacement, deformation temperature and strain rate. In addition, {112}[111] texture forms in the margin of BZ, and {110}[001] texture forms in the center of BZ.
Key words: linear friction welding; TB2 near-β titanium alloy; thermo-physical simulation; deformation behavior; microstructure evolution; microtexture evolution