Cu含量对Mg-2Zn合金组织及性能影响研究  

Microstructures and Properties of Mg-2Zn Alloys with Different Cu Contents

作　　者：张万鹏 马鸣龙 张奎[1,2,3] 李永军 刘小稻[4] 王胜青 Zhang Wanpeng;Ma Minglong;Zhang Kui;Li Yongjun;Liu Xiaodao;Wang Shengqing(State Key Laboratory of Nonferrous Metals and Processes,GRINM Group Co.,Ltd.,Beijing 100088,China;GRIM AT Engineering Institute Co.,Ltd.,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 100088,China;Nanjing Yunhai Special Metals Co.,Ltd.,Nanjing 211224,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 [4]南京云海特种金属股份有限公司,江苏南京211224

出　　处：《稀有金属》2020年第2期113-121,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51204020);国家重点基础研究发展计划项目(2013CB632202);强基工程“高强度镁合金及其变形加工产品”项目(工信部规[2014]95号)资助。

摘　　要：利用光学显微镜(OM)、 X射线衍射仪(XRD)、布氏硬度计、扫描电镜(SEM)、透射电镜(TEM)及Gleeble-1500D热模拟试验机等研究了Cu含量对Mg-2Zn合金显微组织及塑性变形行为的影响。获得了真应力-真应变曲线,进而得到了不同合金在不同变形条件下的动态再结晶临界条件。结果表明:铸态合金主要由α-Mg和共晶组织构成,其主要的第二相为MgCuZn相,随着Cu含量增加,合金中共晶组织体积分数不断增多,晶粒尺寸减小,硬度值升高;热压缩过程中高温时合金的流变应力峰值低于低温,高温促进了合金中位错运动;Cu含量的增加同样会降低合金的峰值应力, Cu含量高的合金经固溶处理后基体中Zn含量逐渐下降,对位错的阻碍作用减弱;合金应力-应变曲线和显微组织均表现出典型的动态再结晶特征,动态再结晶临界应力值随温度升高以及Cu含量增加均降低,合金再结晶程度随之增加;而且合金中MgCuZn相越多,合金的再结晶比例越高。The effects of Cu content on the microstructures and plastic deformation behavior of Mg-2 Zn alloyswere investigated using optical microscope(OM), X-ray diffraction(XRD), brinellhardness tester, scanning electron microscope(SEM), transmission electron microscope(TEM) and Gleeble-1500 D thermal simulation testing machine. The true stress-strain curves and the dynamic recrystallization critical conditions of the alloys in different deformation conditions were obtained. The results showed that the as-cast alloy was mainly composed of α-Mg and eutectic structure, and the main second phase of eutectic was MgCuZn phase. With the increase of Cu content, both the eutectic structure and the hardness value increased, but the grain sizes decreased. As the hot compression temperature increased, the peak value of the flow stress decreased because the high temperature caused dislocation motion to be easy. The increasing of Cu content also reduced the peak stress of the alloy. The alloy with higher Cu content had lower Zn content in the matrix after solution treatment, and the hindranceon dislocation was weakened. The stress-strain curves and microstructures of the alloys all showed typical dynamic recrystallization characteristics. Correspondingly, the dynamic recrystallization critical stress value decreased with temperature and Cu content increasing, and the degree of recrystallization increased. Moreover, the more MgCuZn phase, the higher dynamic recrystallization rate of the alloy.

关 键 词：镁合金 热压缩模拟 动态再结晶 临界条件 

分 类 号：TK91[动力工程及工程热物理]