气体雾化Al-Zn-Mg-Cu铝合金粉末的形貌及组织性能研究.pdfVIP

学兔兔 第28卷第1期 粉末冶金技术 Vo1．28．NO．1 20lO年2月 Powder Metallurgy Technology Feb．2Ol0 气体雾化Al—Zn—Mg—Cu铝合金 粉末的形貌及组织性能研究 王少卿一 于化顺 王海涛 张振亚 闵光辉 (山东大学材料液态结构及其遗传性教育部重点实验室，济南 250061) 摘 要： 利用氮气雾化法制备了A1一Zn—Mg—Cu合金粉末，通过扫描电镜、光学显微镜和x射线衍射仪对粉末 的形貌及组织特征进行了研究；检测了粉末热挤压法制备的合金棒材的力学性能，并对其断口进行了分析。 结果表明：随着粉末颗粒尺寸减小，颗粒形状由以长条形为主转变为以近球形为主。同时，显微组织中的枝晶 臂间距减小，晶粒细化效果明显；合金以a—A1相为主，还有少量町一MgZn 平衡相存在。随粉末颗粒尺寸减小 基体过饱和度增加，基体相和MgZn 相衍射峰宽化；粉末粒度减小，挤压合金力学性能提高；挤压合金拉伸断 口属于韧性断裂。 关键词：快速凝固；高强铝合金；形貌；组织；力学性能 Microstructure and mechanical properties of AI-Zn·Mg·Cu alloy powders prepared by gas atomization process W ang Shaoqing，Yu Huashun，W ang Haitao，Zhang Zhenya，M in Guanghui (Key Laboratory of Liquid Structure and Heredity of Materials，Ministry of Education， Shandong University，Ji’nan 25006 1，China) Abstract：A1一Zn—Mg—Cu alloy powder was fabricated by nitrogen atomization process． The morphology and microstructure of powder，mechanical properties of extruded rods and fracture apperance were studied by scanning electronic microscope(SEM)，optical microscope(OM)and X—ray diffraction(XRD)．The result shows that morphology characteristics of powder changes from strip to near sphericity principally with decrease in size．At the same time，the dendritic arm spacing decrease，which is advantageous to grain refinement．The powder consist of —A1 and a spot of 一MgZn2 equilibrium phase，whose diffraction peaks broa