摘要
为了研究Mg-Zn-Zr-Gd合金的热压缩变形行为,采用Gleeble-3500型热模拟试验机,在变形温度为300~400℃,变形速率为0.001~1 s^(-1)条件下对合金进行热压缩实验。分析了在不同的热压缩条件下合金的真应力-真应变曲线,通过引入Z参数建立了相关流变应力本构方程,同时观察了合金的微观组织演变。结果表明:合金在热压缩变形过程中主要发生了动态再结晶,且合金的流变应力随着应变速率降低和温度升高而减小。在低变形温度或高应变速率下进行热压缩变形时,再结晶晶粒比较细小,但是动态再结晶进行不充分,动态再结晶仅仅发生在晶界处且分布不均匀,仍然存在原始大晶粒。随着变形温度的升高和应变速率的降低,再结晶区域明显增加,再结晶晶粒也逐渐长大。根据热加工图分析得到合金最佳的热加工成形工艺区域为:温度为350~400℃,应变速率为0.1~1 s^(-1)。
In order to study the hot compression deformation behavior of Mg-Zn-Zr-Gd alloy,the hot compression test of the Mg-Zn-Zr-Gd alloy was carried out by using Gleeble-3500 thermal simulation test machine at deformation temperature of 300-400℃and deformation rate of 0.001-1 s^(-1).The true stress-true strain curves of the alloy under different hot compression conditions were analyzed,and the constitutive equation of flow stress was established by introducing Z parameter.Meanwhile,the microstructure evolution of the alloy was observed.The results show that the dynamic recrystallization mainly occurs in the process of hot compression deformation of the alloy,and the flow stress of the alloy decreases with the decrease of strain rate and the increase of temperature.When hot compression deformation is carried out at low deformation temperature or high strain rate,the recrystallized grains are relatively small,but the dynamic recrystallization is not sufficient,the dynamic recrystallization only occurs at the grain boundary and is unevenly distributed,and the original large grains still exist.With the increase of deformation temperature and the decrease of strain rate,the recrystallization region increases obviously,and the recrystallized grains also grow gradually.According to the analysis of the hot processing map,the best suitable hot working forming process parameters of the alloy are:the temperature is 350-400℃,and the strain rate is 0.1-1 s^(-1).
作者
毛训聪
陈乐平
彭聪
MAO Xun-cong;CHEN Le-ping;PENG Cong(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2022年第12期19-27,共9页
Transactions of Materials and Heat Treatment
基金
江西省科技重点研发项目(20212BBE53018)
江西省教育厅科技资助项目(DA202103161)。
