(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用光学显微镜、扫描电子显微镜和透射电子显微镜和室温拉伸实验，研究500 ℃不同时间热暴露对TC11钛合金组织及性能的影响。结果表明：经500 ℃高温长时间暴露后，TC11钛合金的室温拉伸强度略微增加，而塑性明显下降，随着暴露时间的延长，塑性下降趋势减缓; 热暴露400 h后，抗拉强度(σb)提高了30 MPa，断面收缩率(ψ)降低了11.74%。热暴露过程中，合金塑性的降低主要是硅化物和α2相协同作用的结果，其中α2相对力学性能的影响起主导作用；α2相的稳定化和长大过程是合金塑性下降的主要原因。
关键字: TC11钛合金；热暴露；拉伸性能；析出相
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of thermal exposure at 500 ℃ for various time on microstructure and mechanical properties of TC11 titanium alloy were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile test. The results show that tensile strength slightly increases and plasticity decreases significantly after TC11 titanium alloy exposed at 500 ℃ for a long time. The plasticity decrease trend slows down with the extension of exposure time. The tensile strength (σb) increases by 30 MPa, the reduction of area (ψ) decreases by 11.74% after being exposed for 400 h. During thermal exposure, the deterioration of plasticity for TC11 alloy is mainly due to the precipitations of silicides and α2 phases, and in them, the formation of α2 phase plays a main role. For TC11 titanium alloy, the main decrease stage of plasticity results from the coarsening of α2 phase during thermal exposure process.
Key words: TC11 titanium alloy; thermal exposure; tensile property; precipitated phase
