热处理对TC11钛合金室温力学性能的影响

通过光学显微镜、拉伸性能和冲击性能测试仪,研究TC11钛合金经过不同热处理后的显微组织和力学性能。结果表明,280 mm棒材坯料边缘部位室温性能波动与热变形过程中的摩擦力和温降有关;当固溶温度由940℃提高到970℃时,室温强度和塑性均出现了明显的下降,强度下降约50 MPa,延伸率的相对值下降约为8%;固溶温度由970℃升高到980℃时,强度提高约30 MPa,延伸率和断面收缩率均有所提高;时效时间对TC11钛合金室温拉伸性能影响不显著,但对室温冲击性能影响显著,当时效时间由4 h增加到8 h时,显微组织发生了明显的球化,长条状的初生α相数量显著降低,初生α相和次生α相均有所长大,导致冲击性能显著增强,提高了30.4~33.6 J,但室温拉伸强度和塑性变化不大。

Effect of Heat Treatment on Mechanical Properties of TC11 Titanium Alloy at Room Temperature

The microstructures and mechanical properties of TC11 titanium alloy by different heat treatments were studied through optical microscope,tensile property tests and impact tests.The results showed that the fluctuation of properties at room temperature of the edge of φb280 mm bar was related to the friction and temperature dropping during hot working.When the solution temperature was increased from 940 ℃ to 970 ℃,the room temperature strength and plasticity obviously decreased.The strength decreased by about 50 MPa,and the relative value of the elongation about 8％.When solution temperature continued to rise to 980 ℃,the strength increased by about 30 MPa,and the elongation and the reduction of area improved compared with those of 970 ℃.The effect of ageing time on the mechanical properties of TC11 titanium alloy was not significant,but it had a significant effect on the impact at room temperature.When the ageing time increased from 4 h to 8 h,the spheroidization of microstructure was obvious,the number of the elongated primary α phase was significantly reduced,and the primary α phase and secondary α phase grew up,resulting in significant improvement in impact,increasing by 30.4 ～ 33.6 J,but the changes of tensile strength and plasticity at room temperature were not obvious.