(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用光學(xué)顯微鏡、掃描電子顯微鏡和透射電子顯微鏡和室溫拉伸實驗，研究500 ℃不同時間熱暴露對TC11鈦合金組織及性能的影響。結(jié)果表明：經(jīng)500 ℃高溫長時間暴露后，TC11鈦合金的室溫拉伸強度略微增加，而塑性明顯下降，隨著暴露時間的延長，塑性下降趨勢減緩; 熱暴露400 h后，抗拉強度(σb)提高了30 MPa，斷面收縮率(ψ)降低了11.74%。熱暴露過程中，合金塑性的降低主要是硅化物和α2相協(xié)同作用的結(jié)果，其中α2相對力學(xué)性能的影響起主導(dǎo)作用；α2相的穩(wěn)定化和長大過程是合金塑性下降的主要原因。
關(guān)鍵字: TC11鈦合金；熱暴露；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
