(南京航空航天大學(xué) 機(jī)電學(xué)院，南京 210001)
摘 要: 為了研究TA12鈦合金高溫流變行為，構(gòu)建能準(zhǔn)確描述其高溫流變行為的本構(gòu)模型，對(duì)TA12鈦合金進(jìn)行了溫度范圍為700~850 ℃，應(yīng)變速率為0.001~0.1 s-1的高溫拉伸試驗(yàn)。結(jié)果表明：在所研究的變形條件下，流變應(yīng)力隨應(yīng)變的增加而逐漸增大，達(dá)到峰值應(yīng)力后又逐漸減小，直至材料發(fā)生斷裂，并在850 ℃、0.001 s-1的變形條件下出現(xiàn)了穩(wěn)態(tài)流動(dòng)應(yīng)力。綜合考慮應(yīng)變硬化效應(yīng)、應(yīng)變速率硬化效應(yīng)和熱軟化效應(yīng)的影響，提出一種修正的JC本構(gòu)模型，可準(zhǔn)確地描述TA12鈦合金的高溫流變行為。
關(guān)鍵字: TA12鈦合金；高溫流變行為；本構(gòu)模型
（College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210001, China）
Abstract:In order to study the flow behavior of TA12 titanium alloy at high temperature and set up the constitutive model that accurately describes its flow behavior at high temperature, the tensile tests at the temperatures of 700-850 ℃ and at strain rates of 0.001-0.1 s-1 were carried out. The results show that, under the deformation conditions, the flow stress increases with the increase of strain, and then decreases gradually after reaching the peak stress until the material breaks and the steady flow stress occurs at 850 ℃ and 0.001 s-1. Considering the effects of strain hardening, strain rate hardening and thermal softening, a modified JC constitutive model was proposed. It can accurately describe the flow behavior of TA12 titanium alloy at high temperature.
Key words: TA12 titanium alloy; high temperature flow behavior; constitutive model
