Al-Mg-Si合金热压缩变形的流变应力方程

为了给制定和优化热加工工艺参数提供理论依据，采用Gleeble-1500热模拟机研究了含锆Al-Mg-Si合金在变形温度为653~803 K、变形速率为0.01~10s^-1条件下的热压缩变形的流变应力行为，并通过回归法建立材料变形的流变应力数学模型.结果表明：该合金为正应变速率敏感材料，真应力-真应变曲线存在明显的稳态流变特征；流变应力随着变形速率的增加以及变形温度的降低而增加；在较低变形温度条件下，真应力〖CDF*3〗真应变曲线为动态回复曲线；在较高变形温度条件下真应力-真应变曲线为动态再结晶曲线.该合金流变应力σ可用包含Arrhenius项的Zener Hollomon参数的函数来描述，式中A、α和n的值分别为1.89×10¹⁰s^-1、0.024MPa^-1和7.46，热变形激活能Q为166.85kJ/mol.

Flow stress equation for hot compression deformation of Al-Mg-Si alloy

In order to provide the theoretical basis for the establishment and optimization of technological parameters for hot working process, the flow stress behavior of the Al-Mg-Si alloy containing Zr element during hot compression deformation was studied with Gleeble 1500 thermal mechanical simulator at temperatures from 653K to 803K and deformation rates from 0.01 s^-1 to 1 s^-1. In additon, a mathematical model for the flow stress of material deformation was established with regression method. The results show that the alloy is a material sensitive to normal strain rate, and the obvious steady state rheological feature exists on the true stress true strain curves. With increasing the deformation rate and decreasing the deformation temperature, the flow stress increases. The true stress true strain curves are dynamic recovery curves at lower deformation tempertures, and are dynamic recrystallization curves at higher deformation temperatures. The flow stress σ of the alloy can be described by the Zener Hollomon parameter including Arrhenius term, where the values of parameters A, α and n are 1.89×10¹⁰s^-1, 0.024MPa^-1 and 7.46 respectively. Moreover, the activation energy Q for the hot deformation is 166.85kJ/mol.