变质剂改性Zn4Al合金微结构的电镜研究  

An electron microscopy study of the microstructures of modified Zn4Al alloys in relation with properties

作　　者：彭婵娟 赖玉香 向雪梅 宋文豪 周玉琳 陈江华 PENG Chan-juan;LAI Yu-xiang;XIANG Xue-Mei;SONG Wen-hao;ZHOU Yu-lin;CHEN Jiang-hua(Center for High Resolution Electron Microscopy,College of Materials Science and Engineering,Hunan University,Changsha Hunan 410082;Pico Electron Microscopy Center,College of Materials Science and Engineering,Hainan University,Haikou Hainan 570228;Hunan Nonferrous Metals Holding Group CO.LTD.,Changsha Hunan 410015,China)

机构地区：[1]湖南大学高分辨电镜中心,湖南长沙410082 [2]海南大学皮米电镜中心,海南海口570228 [3]湖南有色金属控股集团有限公司,湖南长沙410015

出　　处：《电子显微学报》2022年第4期435-443,共9页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(Nos.52001119,51831004).

摘　　要：利用维氏硬度测试、拉伸测试、扫描电镜、能谱和高角度环形暗场扫描透射电镜,对比研究了三种典型变质剂(Al⁃5Ti⁃B、Sr和RE)的添加对亚共晶Zn4Al合金力学性能与微观组织的影响。结果表明:三种变质剂的添加都可以明显提升Zn4Al合金的强度和塑性,其中,RE变质剂的提升潜力最大。变质剂的添加会改变Zn4Al合金中组织相的形貌:初生η⁃Zn相的形貌由树枝状变成近等轴状,(α+η)共析组织的形貌由片层状为主变成椭球状为主。加入到Zn4Al合金中的变质剂元素一部分形成金属间化合物增大晶界迁移的阻力,一部分偏聚在固液界面形成成分过冷,从而改善了晶粒组织。The effects of three added modifiers(Al⁃5Ti⁃B,Sr,and RE)on the mechanical properties and microstructure of hypoeutectic Zn4Al alloy have been investigated based on Vickers hardness test,tensile test,scanning electron microscope,energy dispersive spectroscopy,and high⁃angle annular dark⁃field scanning transmission electron microscope.The three modifiers can significantly enhance the strength and ductility of Zn4Al alloy,and the RE modifier plays the best role in improving the strength and ductility of Zn4Al alloy.With the addition of modifiers,the morphology of the primaryη-Zn phase transits from dendritic microstructure to nearly equiaxed graininess,and the(α+η)eutectoid microstructure transit from a predominantly lamellar microstructure to a predominantly ellipsoidal microstructure.Parts of the modifier elements added into Zn4Al alloys form intermetallic compounds that strengthen the resistance to grain boundary migration,and parts of them segregate at the solid⁃liquid interface that result in constitutional supercooling,which improves the grain microstructure.

关 键 词：Zn4Al合金 变质处理 显微组织 力学性能 电子显微术 

分 类 号：TG172[金属学及工艺—金属表面处理] TG146.2[金属学及工艺—金属学]