热处理对锻压TA15钛合金棒组织和性能的调控

Regulation of heat treatment on microstructure and properties of forged TA15 titanium alloy bar

对锻压TA15钛合金试样进行700~820℃的退火处理,保温2 h后空冷,研究热处理工艺对锻压TA15钛合金的力学性能的影响。通过观察热处理后锻压TA15钛合金的显微组织变化,统计初生α相的相对体积分数。结果发现,在700~820℃退火处理后,锻压TA15钛合金的显微组织中主要存在初生α相和次生α相,以及较少的基体β相;随着退火温度的升高,初生α相的含量逐渐减少,相对体积分数由70.35%降至46.42%,次生α相的相对体积分数由3.84%升高至18.26%。对比不同热处理温度下试样在室温和高温(500℃)条件下的拉伸性能,820℃退火处理后的试样在室温时的抗拉强度为986 MPa,伸长率为13.5%,强度和塑性具有较好的性能匹配。

The samples of forged TA15 titanium alloy were annealed at 700-820℃and holding for 2 h and then air-cooled,and the influences of heat treatment process on the mechanical properties of forged TA15 titanium alloy were studied.Then,the microstructure changes of forged TA15 titanium alloy after heat treatment were observed,and the relative volume fraction of primaryαphase was calculated.The results show that after annealing at 700-820℃,there are mainly primaryαphase and secondaryαphase,and a few matrixβphases in the microstructure of forged TA15 titanium alloy.With the increasing of annealing temperature,the content of primaryαphase decreases gradually,the relative volume fraction decreases from 70.35%to 46.42%,and the relative volume fraction of secondaryαphase increases from 3.84%to 18.26%.Comparing the tensile properties of the samples at room temperature and high temperature(500℃)under different heat treatment temperatures,the samples after annealing at 820℃have the tensile strength of 986 MPa and the elongation rate of 13.5%at room temperature,and the strength and plasticity have good performance match.