退火态VW84M镁合金热变形行为研究  

Study on Hot Deformation Behavior of Annealed VW84M Magnesium Alloy

作　　者：范佳宾 马鸣龙 张奎 李永军 李兴刚 石国梁 袁家伟 FAN Jiabin;MA Minglong;ZHANG Kui;LI Yongjun;LI Xinggang;SHI Guoliang;YUAN Jiawei(State Key Laboratory of Nonferrous Metals and Process,GRINM Co.,Ltd.,Beijing 100088;GRIMAT Engineering Institute Co.,Ltd.,Beijing 101407;General Research Institute for Nonferrous Metals,Beijing 100088)

机构地区：[1]有研科技集团有限公司有色金属材料制备加工国家重点实验室,北京100088 [2]有研工程技术研究院有限公司,北京101407 [3]北京有色金属研究总院,北京100088

出　　处：《机械工程学报》2023年第8期111-120,共10页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51874062)。

摘　　要：采用Gleeble-3500热模拟试验机对退火态Mg-8.3Gd-4.4Y-1.5Zn-0.8Mn合金进行热压缩试验,研究合金在变形温度为380~500℃,应变速率为0.001~1 s^(-1)和变形程度为60%条件下的热变形行为,计算得到合金的本构关系,根据动态材料模型建立合金不同应变下的热加工图,确定了热变形过程中的可加工区域和流变失稳区,分析不同变形条件下的合金微观组织的演变。结果表明,合金的流变应力随着应变速率的增大而增大,随着变形温度的升高而降低,变形激活能Q=252 517 J/mol,应力指数n=4.55,降低变形速率和提高变形温度均有助于动态再结晶的发生,长周期有序堆垛结构相依据形态影响合金再结晶进程,根据热加工图推断出该材料变形失稳的可能性随着变形程度的增大而增大,结合峰值区域的微观组织判断合适的加工条件是变形温度为460℃,应变速率为0.01 s^(-1)附近。Gleeble-3500 thermal simulation testing machine was used to conduct hot compression experiments on the annealed Mg-8.3Gd-4.4Y-1.5Zn-0.8Mn alloy.The hot deformation behavior of the alloy was investigated at temperatures of 380-500℃,true strain rates of 0.001-1 s^(−1),and a deformation degree of 60%.The constitutive relationship of the alloy was calculated.The hot processing map was established according to the dynamic material model.The machinable and rheological instability regions during the hot deformation process were determined.The evolution of the microstructure under different deformation conditions was analyzed.The results show that the flow stress of the alloy increases with the increase of the strain rate,and decreases with the increase of deformation temperature,the deformation activation energy,Q=252517 J/mol,the stress index,n=4.45;Reducing the deformation rate and increasing the deformation temperature both contribute to the occurrence of dynamic recrystallization.Long period stacking ordered phase affects alloy recrystallization process according to morphology.It is inferred from the hot processing map that the possibility of instability of this material increases with the increase of the degree of deformation.Combining the microstructure in the peak area to judge the appropriate processing conditions are around the deformation temperature of 460℃and the strain rate of 0.01 s^(-1).

关 键 词：Mg-Gd-Y-Zn-Mn合金 热压缩试验 本构关系 热加工图 微观组织 

分 类 号：TG156[金属学及工艺—热处理]