去应力退火对TB15钛合金力学性能和组织的影响

Effects of Stress-relief Annealing on Mechanical Properties and Microstructure of TB15 Titanium Alloy

利用金相显微镜、拉伸试验机和扫描电子显微镜等手段研究了不同去应力退火工艺对TB15钛合金力学性能、断口形貌和显微组织的影响。结果表明:经去应力退火后,残余应力大幅度下降;去应力退火对TB15钛合金的拉伸强度和拉伸塑性影响较小,而断裂韧性受热处理影响较大,与无去应力退火试样相比,断裂韧性降低较为显著;不同去应力退火试验后,TB15钛合金的组织相差不大,未去应力退火断裂韧性断口组织较去应力退火后更粗糙。

The effects of different stress-relief annealing on the mechanical properties,fracture morphology and microstructure of TB15 titanium were studied by using metallographic microscope,tensile testing machine and scanning electron microscopy.The results show that the residual stress decreases significantly after stress-relief annealing.Stress-relief annealing has little effect on the tensile strength and tensile plasticity of TB15 titanium alloy,while the fracture toughness is greatly affected by heat treatment.Compared with the specimens without stress-relief annealing,the fracture toughness decreases significantly,the microstructure of TB15 titanium alloy changes little after the different destress annealing test and the fracture microstructure is coarser than that of after stress-relief annealing.