(华南理工大学 国家金属材料近净成形工程技术中心，广州 510640)
摘 要: 为了系统研究半固态7050铝合金的触变力学行为，采用Gleeble-3500热模拟试验机对SIMA法制备的半固态7050铝合金进行单向压缩试验，利用SPPS数理统计软件拟合材料本构模型，最后通过MSC.MARC软件进行半固态轧制过程的数值模拟。结果表明：7050铝合金的压缩流变应力与温度、应变速率以及应变具有相关性，在0.1~10 s-1的应变速率范围内，流变应力随温度的升高而明显降低，随应变速率和变形量的增大而增大；利用压缩试验测得真应力—真应变关系，可以建立半固态7050铝合金分阶段触变变形的粘塑性本构模型，该模型基于半固态材料的力学特性，并考虑液相分数的影响；模拟计算得到的稳态轧制力约为25 MPa，与实际轧制实验结果基本吻合，证明所建立的本构模型是合理的。
关键字: 半固态；热模拟；本构方程；轧制
（National Engineering Research Center of Near-net-shape Forming Technology for Metallic Materials,
South China University of Technology, Guangzhou 510640, China）
Abstract:In order to investigate the thixo-forming deformational behavior of 7050 aluminum alloy systematically, the semi-solid material prepared by SIMA method was studied on the Gleeble-3500 material thermo-simulation machine via uniaxial compression tests. The viscoplastic model of flow stress at semi-solid temperature was established by using SPSS software. At last, the rolling process was simulated by MSC.MARC finite element software. The results show that, the compression flow stress of 7050 aluminum alloy has a close relationship with temperature, strain rate and strain. In the strain range from 0.1 s-1 to 10 s-1, the flow stress decreases significantly with the temperature increasing and rises considerably with the strain and strain rate increasing. The two-stage viscoplastic model of flow stress is established by using the obtained true strain—true strain rate curves, which considers the mechanical properties of semi-solid state material and liquid fractions. The simulation results show the stable rolling force is around 25 MPa, which agrees with experimental results. So, the established constitutive equations are reasonable.
Key words: semi-solid; thermo-simulation; constitutive equations; rolling
