(大連交通大學(xué) 連續(xù)擠壓工程研究中心，大連 116028)
摘 要: 采用Gleeble-1500型熱模擬試驗(yàn)機(jī)進(jìn)行高溫壓縮實(shí)驗(yàn)，結(jié)合連續(xù)擠壓工藝制定熱壓縮實(shí)驗(yàn)方案，研究鋁鍶合金高溫塑性變形行為，分析變形溫度、應(yīng)變速率對(duì)鋁鍶合金熱變形過(guò)程中流變應(yīng)力和Al4Sr相形態(tài)的影響，并采用線性回歸的方法建立鋁鍶合金高溫下的本構(gòu)方程。結(jié)果表明：鋁鍶合金的熱塑性變形軟化機(jī)制以動(dòng)態(tài)回復(fù)為主；在熱變形過(guò)程中流變應(yīng)力隨變形溫度的升高而減小，隨應(yīng)變速率的增大而增大；變形溫度為400 ℃時(shí)Al4Sr相破裂嚴(yán)重，而當(dāng)溫度為500 ℃時(shí)Al4Sr相具有韌性而易于彎曲；可用包含Zener-Hollomon參數(shù)的Arrhenius雙曲正弦模型描述其熱變形行為。
關(guān)鍵字: 鋁鍶合金；高溫塑性變形；流變應(yīng)力；顯微組織；本構(gòu)方程
（Engineering Research Center of Continuous Extrusion, Dalian Jiaotong University, Dalian 116028, China）
Abstract:The pyroplastic deformation experiment of Al-Sr alloy was studied on the Gleeble-1500 thermal-mechanical simulator, which was based on the continuous extrusion process. The pyroplastic deformation behavior of Al-Sr alloy was systematically studied the effects of deformation temperature and strain rate on the flow stress and Al4Sr phase of Al-Sr alloy during hot deformation were analyzed, and the constitutive equation of Al-Sr alloy by linear regression analysis was established. The results show that the main softening mechanism of the Al-Sr alloy under the pyroplastic deformation is dynamic recovery; and the rheological stress decreases with increasing the temperature, and increases with increasing the strain rate. When the deformation temperature was 400 ℃, the Al4Sr phase break seriously; once the deformation temperature was 500 ℃, the particles become ductile and flexible. The thermal deformation behavior can be described by the Arrhenius hyperbolic sine equation with Zener-Hollomon parameters.
Key words: Al-Sr alloy; pyroplastic deformation; rheological stress; microstructure; constitutive equation
