挤压温度对纯镁组织演变、力学性能和断裂行为的影响  

Effect of extrusion temperature on microstructure evolution, mechanical properties and fracture behavior of pure magnesium

作　　者：徐文良 李成杰 李学问[2] XU Wen-liang;LI Cheng-jie;LI Xue-wen(Institute of Materials,Chinese Academy of Engineering Physics,Jiangyou 621700,China;School of Materials Science and Engineering,Harbin University of Science and Technology,Harbin 150080,China)

机构地区：[1]中国工程物理研究院材料研究所,四川江油621700 [2]哈尔滨理工大学材料科学与工程学院,黑龙江哈尔滨150080

出　　处：《材料热处理学报》2021年第4期48-53,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51801192)。

摘　　要：利用光学显微镜、万能力学试验机和扫描电镜等研究了不同温度下挤压变形对铸态商业纯镁显微组织、力学性能和断裂行为的影响。结果表明,挤压变形显著地细化纯镁的晶粒尺寸,极大地提高了纯镁的力学性能。经过挤压以后,纯镁的平均晶粒尺寸被细化到18.6μm以下,最小达7.9μm;挤压态纯镁的拉伸屈服强度提高到140 MPa以上,抗拉强度提高到210~220 MPa,室温伸长率达到12%~14.7%。晶粒细化不仅提高了纯镁的综合力学性能,也改变了纯镁的拉伸断裂行为,其断裂方式由铸态的脆性断裂变成了挤压态的微孔聚集型断裂。Effect of extrusion deformation at different temperatures on microstructure, mechanical properties and fracture behavior of as-cast pure magnesium was studied by means of optical microscope, universal mechanical testing machine and scanning electron microscopy.The results show that the extrusion deformation significantly refines the grain size of the pure magnesium and greatly improves its mechanical properties.The average grain size of the pure magnesium is refined to below 18.6 μm after extrusion, and the smallest average grain size is 7.9 μm.The yield strength of the pure magnesium after extrusion is increased to more than 140 MPa, the tensile strength is increased to 210-220 MPa, and the elongation at room temperature reaches 12%-14.7%.Grain refinement not only improves the comprehensive mechanical properties of the pure magnesium, but also changes the tensile fracture behavior of pure magnesium, and the fracture mode of the as-cast pure magnesium changes from brittle fracture to micropore aggregation fracture after extrusion.

关 键 词：纯镁 挤压 显微组织 力学性能 断裂行为 

分 类 号：TG146.2[一般工业技术—材料科学与工程]