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在350℃下,对挤压态ZK60镁合金分别进行1、4、8道次的往复挤压变形(CEC)。利用金相显微镜(OM)、透射电镜(TEM)观察往复挤压前后ZK60镁合金的微观组织,利用X射线衍射仪(XRD)分析变形前后晶面取向变化,在万能拉伸试验机上测试变形前后镁合金的力学性能,并利用扫描电镜(SEM)观察拉伸断口形貌。往复挤压后的检测结果表明,挤压态ZK60镁合金晶粒显著细化,晶粒尺寸分布较均匀,随着挤压道次增多,晶粒尺寸逐渐减小;1道次变形后组织内产生了大量晶格缺陷,出现了大角度晶界,第二相粒子分布在晶粒内部和晶界上;各晶面衍射峰增强,拉伸断口内存在大量基体撕裂棱和明显的韧窝分布;ZK60镁合金的力学性能变化较大,随着挤压道次增多,伸长率大幅提高,抗拉强度小幅增大,而屈服强度降低。
The reciprocating extrusion deformation (CEC) of ZK60 magnesium alloy was carried out for 1,4,8 times at 350 ℃. The microstructures of ZK60 magnesium alloy before and after reciprocating extrusion were observed by optical microscope (OM) and transmission electron microscope (TEM). The changes of crystal orientation before and after deformation were analyzed by X-ray diffraction (XRD) Magnesium alloy mechanical properties, and the use of scanning electron microscopy (SEM) observed tensile fracture morphology. The results of reciprocating extrusion showed that the grain size of ZK60 magnesium alloy in the as-extruded state was significantly refined and the grain size distribution was more uniform. With the increase of extrusion pass, the grain size decreased gradually. After the first pass deformation, A large number of lattice defects were formed and large-angle grain boundaries appeared. The second-phase particles were distributed on the grain boundaries and grain boundaries. The diffraction peaks of all the crystal planes were enhanced. There were a large number of matrix tearing edges and obvious dimples The mechanical properties of ZK60 magnesium alloy vary greatly. With the increase of extrusion pass, the elongation increases greatly, the tensile strength increases slightly and the yield strength decreases.