挤压态AZ40镁合金热变形行为及热加工图分析  

Analysis of hot deformation behavior and processing map of extruded AZ40 alloy

作　　者：支盛兴 李兴刚 袁家伟[1,2,3] 李永军 马鸣龙[1,2,3] 石国梁 张奎[1,2,3] ZHI Sheng-xing;LI Xing-gang;YUAN Jia-wei;LI Yong-jun;MA Ming-long;SHI Guo-liang;ZHANG Kui(State Key Laboratory of Nonferrous Metals and Process,GRINM Group Corporation Limited(GRINM),Beijing 100088,China;GRIMAT Engineering Institute Co.,Ltd.,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 100088,China)

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：《材料工程》2021年第11期136-146,共11页Journal of Materials Engineering

摘　　要：采用Gleeble-3500热模拟试验机对挤压态AZ40合金进行热压缩实验,分析压缩后不同温度真应力-应变曲线的变化趋势,得到流变应力受变形温度和应变速率等因素的影响规律;在双曲正弦关系的基础上构造挤压态AZ40合金的本构方程,在动态材料模型(DMM)基础上建立挤压态AZ40合金的热加工图,从而确定挤压态AZ40镁合金的热变形加工范围。结果表明:明显的动态再结晶是挤压态AZ40镁合金流变曲线的特点,在压缩过程中,随变形温度的升高,挤压态AZ40镁合金的峰值应力减小;随应变速率升高,挤压态AZ40镁合金的峰值应力增大。当变形温度相同时,动态再结晶晶粒比例随着应变速率的升高而降低;当应变速率相同时,动态再结晶晶粒大小随着变形温度的升高而增大。粗大的未再结晶晶粒有明显的<1010>||ND和<2110>||ND两种取向,而再结晶晶粒取向随机;通过热加工图及组织分析,确定了最佳的加工工艺为T=573 K,ε0.1s^(-1)。The Gleeble-3500 thermal simulation tester was used to perform hot deformation behavior on the extruded AZ40 Mg alloy to analyze the trend of the true stress-strain curve after compression and to obtain the influence of the flow stress on the deformation temperature and strain rate.Subsequently,the constitutive equation was constructed for extruded AZ40 alloy based on the hyperbolic-sine relationship,and the thermal processing map of extruded AZ40 alloy was established based on the dynamic material model(DMM),thereby estimating the processing range of extruded AZ40 alloy.The results show that the rheological curve of extruded AZ40 alloy is characterized by obvious dynamic recrystallization.Furthermore,during the compression process,the peak stress of extruded AZ40 alloy decreases with the increase of deformation temperature,while increases with the increase of strain rate.Moreover,the proportion of dynamic recrystallized grains(DRGs)decreases with the increase of the strain rate under the same deformation temperature condition;while the DRGs size increases with the increase of the deformation temperature under the same strain rate condition.The coarse uncrystallized grains show obvious crystallographic orientations of<1010>||ND and<2110>||ND,while crystallographic orientation of DRGs is random distributed.Finally,through thermal processing map and tissue analysis,the optimal processing window was identified as T=573 K,ε0.1s^(-1).

关 键 词：AZ40合金 热变形 本构方程 热加工图 织构 

分 类 号：TG146.2[一般工业技术—材料科学与工程]