摘要
目的通过热模拟实验研究挤压态Mg-8.5Gd-4.5Y-0.7Zn-0.4Zr合金的本构方程及加工图。方法在Gleeble热模拟机上开展应变速率为0.001~1 s^(-1),变形温度为300~450℃条件下的单轴热压缩实验。根据动态材料模型,建立合金的热加工图,分析功率耗散因子随变形温度、应变速率和应变的变化规律。结果合金的流变应力在不同的变形温度和应变速率下表现出不同的特征,流变应力与变形温度和应变速率的关系可用双曲正弦本构关系来描述,其平均激活能为209.223 kJ/mol,应力指数为3.442。合金的失稳区出现在变形温度为420~450℃,应变速率为0.1~1 s^(-1)的范围内。结论得到了挤压态合金的本构方程,合金最佳热加工工艺参数为变形温度为400℃,应变速率为1 s^(-1)。
The work aims to study the constitutive equation and processing map of an as-extruded Mg-Gd-Y-Zn-Zr alloy by isothermal compression tests.Homotaxial isothermal compression test was conducted on Gleeble simulated machine at 0.001 s^(-1)to 1 s;and 300℃to 450℃.The processing map was established according to dynamic material model.The variation of power dissipation factor with deformation temperature,strain rate and strain was analyzed.The flow stress of the alloy showed different characterizations under different temperature and strain rate.The relationship between flow stress,deformation temperature and strain rate can be expressed by hyperbolic sine function.The average activation energy was 209.223 kJ/mol,and the stress exponent was 3.442.The deformation temperature in the instability regions of the alloy was 420~450℃and strain rate was 0.1~1 s^(-1).The constitutive equation of the as-extruded alloy is obtained.The optimum hot working condition for as-extruded Mg-Gd-Y-Zn-Zr alloy is determined to be 400℃and 1 s^(-1).
作者
李建平
夏祥生
LI Jian-ping;XIA Xiang-sheng(Intelligent Manufacturing and Automobile School,Chongqing College of Electronic Engineering,Chongqing 401331,China;No.59 Research Institute of China Ordnance Industry,Chongqing 400039,China)
出处
《精密成形工程》
北大核心
2022年第2期95-100,共6页
Journal of Netshape Forming Engineering
关键词
镁合金
本构方程
加工图
显微组织
magnesium alloy
constitutive equation
processing map
microstructure
