(1. 大連理工大學(xué) 材料科學(xué)與工程學(xué)院，大連116024；
2. 大連理工大學(xué) 機(jī)械工程學(xué)院，大連 116024；
3. 大連理工大學(xué) 汽車工程學(xué)院，大連 116024)
摘 要: 基于6061-T6鋁合金在高溫變形過(guò)程中的動(dòng)態(tài)回復(fù)、動(dòng)態(tài)再結(jié)晶及變形硬化特性，分析其在不同溫度階段的黏塑性特征，在高溫階段進(jìn)一步引入軟化因子修正傳統(tǒng)Field-Backofen模型，使之適用于鋁合金溫成形的熱力本構(gòu)描述。通過(guò)NAKAJIMA凸模脹形數(shù)值仿真及試驗(yàn)對(duì)比發(fā)現(xiàn)：高低溫(25~400 ℃)相結(jié)合的軟化型熱拉伸本構(gòu)方程可以準(zhǔn)確地描述板料破裂前的集中軟化特征，且可以有效滿足6061鋁合金高溫成形性能的仿真需求。
關(guān)鍵字: 6061鋁合金；溫成形；熱力拉伸；本構(gòu)模型；數(shù)值仿真
（1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
2. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China;
3. School of Automotive Engineering, Dalian University of Technology, Dalian 116024, China）
Abstract:Based on the dynamic recovery, dynamic recrystallization and deformation hardening characteristics of 6061-T6 aluminum alloy happened in the high temperature deformation process, the viscoplastic features at different temperatures were analyzed. The modified Field-Backofen model introduced with a softening factor was put forward to describe the thermal mechanics and constitutive model of aluminum alloy for hot forming. Combined with the experimental and simulation comparison research of NAKAJIMA test, the softening constitutive equation in the temperature range of 25-400 ℃ for hot forming is obtained and especially suitable for describing the behavior of sheet concentrate softening before crack, which is verified to be effective while applied to numerical simulation of forming process for 6061 aluminum alloy in hot forming.
Key words: 6061 Al alloy; hot forming; thermal tensile; constitutive model; numerical simulation
