摘要
为了确定Mg-4Zn合金高温塑性变形过程中的最优可加工区间,应用Gleeble-3800热力模拟试验机获得了Mg-4Zn合金在变形温度200~350℃、应变速率0.001~1 s^-1范围内的流动应力曲线,利用实验数据建立了Mg-4Zn合金热变形过程的本构方程和基于Murty失稳准则的加工图。结果表明:Mg-4Zn合金的热压缩本构方程可以用双曲正弦函数描述,其变形激活能为113.087 kJ·mol^-1,模型计算的应力值与实验值之间的相关性系数为0.975,平均相对误差为7.5%,说明所建立的模型能够较好地预测峰值应力;加工图上存在3个失稳区和3个可加工区,结合本构方程、加工图和微观组织分析,可加工区间I(280~350℃,0.25~1 s^-1)具有动态再结晶充分、晶粒尺寸均匀细小、变形抗力低和加工效率高的特点,是Mg-4Zn合金的最优可加工区间。
To determine the optimal workability domains of Mg-4 Zn alloy during the high-temperature plastic deformation,Gleeble-3800 thermal simulator was applied to obtain the flow stress curves of Mg-4 Zn alloy at the deformation temperature of 200-350℃and strain rate of 0.001-1 s^-1.The test data was used to establish the constitutive equation of Mg-4 Zn alloy during the hot deformation and the processing map based on the Murty instability criterion.The results show that the constitutive equation of Mg-4 Zn alloy can be described by hyperbolic sine function,and its deformation activation energy is 113.087 k J·mol^-1.The correlation coefficient between the calculated values of the model and the test values is 0.975,and the average relative error is 7.5%,which shows that the established model can predict the peak stress well.There are three instability domains and three workability domains on processing map.Combined with the constitutive equation,processing map and microstructure analysis,the workability domain I(280-350℃,0.25-1 s^-1)is characterized by full dynamic recrystallization,uniform and fine grain size,low deformation resistance and high processing efficiency,and is the optimal workability domain of Mg-4 Zn alloy.
作者
骆晓东
孙亚伟
李南南
韦源源
赵玲玉
金朝阳
LUO Xiao-dong;SUN Ya-wei;LI Nan-nan;WEI Yuan-yuan;ZHAO Ling-yu;JIN Zhao-yang(School of Mechanical Engineering,Yangzhou University,Yangzhou 225009,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2020年第9期167-173,共7页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51901202)
江苏省基础研究计划(自然科学基金)面上项目(BK20191442)
扬州大学中青年学术带头人资助项目。
关键词
镁合金
本构方程
加工图
微观组织
可加工区间
magnesium alloy
constitutive equation
processing map
microstructure
workability domains
作者简介
通信作者:金朝阳,女,1973年生,博士,教授,主要从事难变形金属控形控性一体化制造研究,E-mail:zyjin@yzu.edu.cn;第一作者:骆晓东,男,1994年生,硕士研究生,主要从事高性能轻合金控形控性一体化研究,E-mail:18762327767@163.com。
