摘要
以新型高强韧Al-Zn-Mg-Cu合金为研究对象,借助Gleeble-3500热模拟机开展了热压缩试验,变形温度为310~470℃,应变速率为0.001~1 s^(-1),真应变为1.2。利用试验数据建立了该合金的本构方程和热加工图,采用SEM和EBSD对典型试样变形后的微观组织进行了观察,对热加工图的可靠性进行了验证。结果表明,该新型合金的真应力-真应变曲线表现出典型的动态回复特征,流变应力进入稳态阶段所需要的应变值较低,软化作用比较强;计算得到该合金的变形激活能为112.45 kJ·mol^(-1),其值较低,表明该种材料具备较好的成形能力;本构方程预测结果的平均准确率达到96.2%,表明本构方程能够对该合金的流变行为进行指导;通过选取热加工图中的高功率耗散区域并针对局部区域组织进行特征分析,最终确定了变形温度455~470℃,应变速率0.015~0.2 s^(-1)为最佳的加工区域,采用获取的最佳工艺参数开展物理试验,合金抗拉强度达到了665 MPa,伸长率达到了15%。
Taking new-type Al-Zn-Mg-Cu alloy with high strength and ductility as research object,the thermal compression test was carried out using Gleeble-3500 thermal simulator.The deformation temperature was 310-470℃,the strain rate was 0.001-1 s^(-1)and the true strain was 1.2.The constitutive equation and hot processing map of the alloy were established by test data.The microstructure of typical samples after deformation was observed by SEM and EBSD,and the reliability of hot processing map was verified.The results show that the true stress-true strain curve of new-type alloy shows typical dynamic recovery characteristic.The flow stress requires a lower strain value to enter steady state stage,and the softening effect is stronger.The calculated activation energy for deformation of the alloy is112.45 kJ·mol^(-1),which is relatively low,indicating that the material has good forming ability.The average accuracy rate of constitutive equation prediction result reaches 96.2%,which proves that the constitutive equation can guide the rheological behavior of this alloy.By selecting high power dissipation area of the hot processing map and analyzing the local area structure characteristics,it is finally determined that the deformation temperature of 455-470℃and strain rate of 0.015-0.2 s^(-1)is the best processing area.The physical test was carried out with the obtained optimal process parameters.The tensile strength of alloy reaches 665 MPa and the elongation reaches15%.
作者
高明
赵熹
刘杰
张博循
张治民
GAO Ming;ZHAO Xi;LIU Jie;ZHANG Bo-xun;ZHANG Zhi-min(College of Mechanical&Electrical Engineering,North University of China,Taiyuan 030051,China;National Defense Industry Innovation Center for Complex Component Extrusion Technology,North University of China,Taiyuan 030051,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2021年第3期126-136,共11页
Journal of Plasticity Engineering
基金
国家科技重大专项项目(2019ZX04022001-004)。
关键词
新型高强韧Al-Zn-Mg-Cu合金
热压缩
本构方程
热加工图
new-type Al-Zn-Mg-Cu alloy with high strength and ductility
thermal compression
constitutive equation
hot processing map
