中文摘要：

在变形温度350~500℃、应变速率0.001~5 s-1的条件下采用Gleeble-1500D热压缩模拟试验机对挤压铸造Al-17.5Si-4Cu-0.5Mg合金进行热压缩试验。研究了该合金在热变形条件下的流变应力行为,并建立该合金热变形时的本构方程。结果表明合金流变应力随应变速率的增加和变形温度的降低而上升;在相同的变形条件下,挤压铸造合金比重力铸造合金流变应力水平更高。建立了挤压铸造合金的热加工图,得出挤压铸造合金更适合在高温低速下变形。

英文摘要：

The hot compression tests of squeeze casting Al-17.5Si-4Cu-0.5Mg alloy were carried out at 350-500℃ and strain rate of 0.001-5 s-1 on hot-simulation machine Gleeble-1500D. The flow stress behavior of the alloy in the therrno deformation was studied, and the constitutive equation of the alloy was established during hot deformation. The results show that： the flow stress increases with the strain rate increasing and the deformation temperature decreasing. The flow stress level of the alloy by squeeze casting is higher compared with gravity casting under the same deformation condition. The hot processing maps for squeeze casting alloy are established. It can be obained that the squeeze casting alloy is suit to deform under high temperature and low strain rate.