(1. 南昌航空大學(xué) 航空制造工程學(xué)院，南昌 330063；
2. 北京航空材料研究院，北京 100095)
摘 要: 借助熱模擬試驗(yàn)機(jī)研究TiAl合金在變形溫度為1273~1523 K、應(yīng)變速率為 0.001~1 s-1和變形程度為50%條件下的熱變形行為；分析流變應(yīng)力曲線特征，構(gòu)建基于應(yīng)變補(bǔ)償?shù)奈锢肀緲?gòu)模型；考慮TiAl合金的彈性模量和自擴(kuò)散系數(shù)與溫度的關(guān)系，基于動(dòng)態(tài)材料模型建立該合金的加工圖，確立合適的熱加工工藝參數(shù)。結(jié)果表明：TiAl合金具有正應(yīng)變速率敏感性和負(fù)溫度敏感性，流變應(yīng)力曲線主要表現(xiàn)為動(dòng)態(tài)再結(jié)晶軟化機(jī)制；所建立的物理本構(gòu)模型的預(yù)測值與實(shí)驗(yàn)值具有較好的吻合度；根據(jù)加工圖的分析，該合金適宜的變形參數(shù)范圍為1360~1523 K、0.001~0.02 s-1。
關(guān)鍵字: TiAl合金；物理本構(gòu)模型；加工圖；流變應(yīng)力
（1. School of Aerospace Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China;
2. Beijing Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:Hot deformation behavior of TiAl alloy was studied at the temperature range of 1273-1523 K, strain rate range of 0.001-1 s-1 and maximum deformation degree of 50% with thermal simulator. The characteristics of the flow stress curve were analyzed. The physical constitutive model based on strain compensation was constructed, which took into account the relationship between elastic modulus and self-diffusion coefficient and temperature for TiAl alloy. The suitable thermal processing parameter of the alloy were established by processing maps based on dynamic material model (DMM). The results show that TiAl alloy has positive strain rate sensitivity and negative temperature sensitivity, and the flow stress curves are mainly characterized by dynamic recrystallization softening mechanism. The predicted values of the physical constitutive model are in good agreement with the experimental values. According to the analysis of processing maps for the alloy, the range of appropriate thermal processing parameters are 1360-1523 K and 0.001-0.02 s-1.
Key words: TiAl alloy; physical constitutive model; processing map; flow stress
