(西北工業(yè)大學(xué) 材料學(xué)院，西安 710072)
摘 要:
研究變形工藝參數(shù)對TC4鈦合金高溫變形行為的影響。熱模擬壓縮實(shí)驗(yàn)時選取的變形溫度為1 093~1 303 K；應(yīng)變速率為0.001~10.0 /s；變形程度為60%。結(jié)果表明：TC4鈦合金在變形開始階段，流動應(yīng)力隨應(yīng)變的增加迅速增加，當(dāng)應(yīng)變超過一定值后，流動應(yīng)力開始下降并逐漸趨于穩(wěn)定，出現(xiàn)穩(wěn)態(tài)流動特征；變形溫度升高和應(yīng)變速率減小使TC4鈦合金高溫變形時的穩(wěn)態(tài)應(yīng)力和峰值應(yīng)力顯著降低；應(yīng)變速率和變形溫度會影響TC4鈦合金進(jìn)入穩(wěn)態(tài)變形時變形程度的大小。利用多元回歸分析建立TC4鈦合金在高溫變形時的流動應(yīng)力模型，模型的計(jì)算值與實(shí)驗(yàn)數(shù)據(jù)的平均相對誤差為6.25%，該模型較好地描述TC4鈦合金在高溫變形過程中的流動行為。
關(guān)鍵字: TC4鈦合金；高溫變形行為；流動應(yīng)力模型；工藝參數(shù)
（School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The effect of processing parameters on deformation behavior of TC4 titanium alloy were investigated by using compression tests. The experiments were carried out in a Thermermaster-Z simulator at deformation temperatures of 1 093− 1 303 K, strain rates of 0.001−10.0 s−1, and height direction reduction of 60%. The results show that the flow stress of TC4 titanium alloy increases quickly with the strain and reaches a peak, then decreases to a steady value. The steady and peak stress significantly decreases with the increase of deformation temperature and decrease of strain rate, and the strain rate and the deformation temperature would also affect the critical value of strain to reach the steady flow of TC4 titanium alloy during high temperature deformation. The flow stress model of TC4 titanium alloy during high temperature deformation was established by using the regression method. The average relative difference between the calculated and experimental flow stress is 6.25%. The flow stress model can efficiently predict the deformation behavior of TC4 titanium alloy during high temperature deformation.
Key words: TC4 titanium alloy; high temperature deformation behavior; flow stress model; processing parameters
