Mg-12Gd(-4Y)-0.5Zr合金热压缩变形行为及热加工图  

Hot Compression Deformation Behavior and Processing Map of Mg-12Gd(-4Y)-0.5Zr Alloy

作　　者：赵振良 李全安[1,2,3] 陈晓亚 梅婉婉[1] 谭劲峰 Zhao Zhenliang;Li Quanan;Chen Xiaoya;Mei Wanwan;Tan Jinfeng(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal new Materials and Advanced Processing Technology,Luoyang 471023,China;Longmen laboratory,Luoyang 471000,China;CHINALCO Luoyang Copper Co.,LTD.,Luoyang 471003,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属新材料与先进加工技术省部共建协同创新中心,河南洛阳471023 [3]龙门实验室,河南洛阳471000 [4]中铝洛阳铜加工有限公司,河南洛阳471003

出　　处：《中国稀土学报》2025年第1期162-172,共11页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(52201119);中原英才计划—中原青年拔尖人才项目(豫组通(2021)44号);河南省自然科学基金项目(222300420435);龙门实验室前沿探索课题(LMQYTSKT014)资助。

摘　　要：研究了Mg-12Gd-0.5Zr(GW120K)合金和Mg-12Gd-4Y-0.5Zr(GW124K)合金在350~500℃,应变速率为0.002~1 s^(-1)的热压缩行为,对合金的流变应力、显微组织进行分析,计算了合金的热变形激活能,构建并分析了合金的热加工图。结果表明:两种合金的真应力真应变曲线都表现出动态再结晶的一般特征。添加Y后,合金的流变应力增高;在低温高应变速率(350℃,0.002 s^(-1))变形时,合金易出现45°角剪切断裂;在400℃变形时,在动态再结晶的晶界处析出第二相,添加Y后GW124K合金动态析出相的数量明显增多;在500℃变形时,发生完全动态再结晶,GW124K合金的再结晶晶粒尺寸(25μm)明显小于GW120K合金(40μm);GW120K合金的热变形激活能为218.788 k J·mol^(-1),添加Y后合金的热变形激活能增高至243.530 k J·mol^(-1);Mg-12Gd-(4Y)-0.5Zr两种合金的失稳区集中在低温高应变区域,添加Y后,合金的失稳区增大,可加工区域减小。The hot compression experiments of Mg-12Gd-0.5Zr(GW120K) alloy and Mg-12Gd-4Y-0.5Zr(GW124K) alloy at 350-500 ℃ and strain rate of 0.002-1 s^(-1) were studied. The flow stress and microstructure were analyzed, the activation energy of hot deformation was calculated, and the hot processing map was constructed and analyzed.The results show that the true stress-true strain curves of the two alloys show the general characteristics of dynamic recrystallization. After adding Y, the flow stress increases. When deformed at low temperature and high strain rate(350 ℃, 0.002 s^(-1)), the alloy is prone to 45° angle shear fracture. When deformed at 400 ℃, the dynamic precipitate nucleates at the grain boundary of dynamic recrystallization. After adding Y, the number of dynamic precipitates in GW124K alloy increases obviously. When deformed at 500 ℃, complete dynamic recrystallization occurs, and the recrystallized grain size of GW124K alloy(25 μm) is significantly smaller than that of GW120K alloy(40 μm). The hot deformation activation energy of GW120K alloy is 218.788 kJ·mol^(-1). After adding Y, the hot deformation activation energy increases to 243.530 kJ·mol^(-1). The instability region of Mg-12Gd-(4Y)-0.5Zr alloy is concentrated in the low temperature and high strain region. After adding Y, the instability region increases, while the machinable region decreases.

关 键 词：Mg-12Gd(-4Y)-0.5Zr合金 热压缩 激活能 热加工图 

分 类 号：TG146.22[一般工业技术—材料科学与工程]