热挤压后纯镁的组织与力学性能研究

Microstructure and Mechanical Properties of Pure Magnesium After Hot Extrusion

将φ30 mm工业纯镁圆锭在300℃的模具中进行热挤压,制备出φ10 mm且表面光滑而无明显裂纹的纯镁挤压试样。使用光学显微镜(OM)观察了热挤压后试样的组织结构,使用电子万能试验机测试了其力学性能,并用扫描电子显微镜(SEM)对纯镁热挤压前后的拉伸断口进行了分析。结果表明,经过热挤压后,纯镁的晶粒得到明显细化,组织均匀,力学性能优异,拉伸强度和屈服强度分别达到183、182 MPa,比未挤压前试样明显提高。

Commercial pure Mg ingot with a diameter of 30 mm was extruded through the die at 300℃, and then pure Mg extrusion sample with a diameter of 10 mm was prepared, in which the surface was smooth without any obvious crack. The microstructure of the specimen after hot extrusion was observed by optical microscope （OM） and the tensile properties were also measured with electronic universal testing machine. And the tensile fractures before and after hot extrusion of pure Mg were observed by scanning electron microscopy（SEM）. The results show that after hot extrusion the grains of pure Mg are obviously fined, the microstructure is uniform and mechanical properties are excellent. The tensile strength and yield tensile strength reach 183 MPa and 182 MPa respectively, which are significantly improved than that of the sample before extrusion.