【作者】 许泽清； 张红霞； 闫志峰； 张欣；

【Author】 Zeqing Xu;Hongxia Zhang;Zhifeng Yan;Xin Zhang;College of Materials Science and Engineering,Taiyuan University of Technology;

【机构】 太原理工大学材料科学与工程学院；

【摘要】 本试验采用TIG焊焊接了AZ31B镁合金板材,对镁合金试样以及焊缝试样进行了三点弯曲测试以及基于此类载荷的低周疲劳测试以获得试样及其焊缝的抗弯强度。通过对试样在试验过程中的应力分布进行了分析,获得了横向、纵向以及上支点与下支点连线接的应力分布曲线。此外利用SEM观察了试样试验后获得的断口,表明镁合金在三点弯曲载荷下的断裂方式为准解理断裂。根据断口微观图像和裂纹的微观金相组织,分析了试样的裂纹扩展路径以及断裂机理,并提出了提高试样三点弯曲低周疲劳性能的建议。更多还原

【Abstract】 The AZ31 B magnesium alloy sheet was welded by TIG welding in this experiment,and both of three points bending tests and low cycle fatigue test based on three point bending were carried out to gain the fatigue strength of the sample its welding joint.The stress distribution curves of lateral,longitudinal and line between fulcrums(top and bottom) were patterned through analysing the stress distribution of specimens in the fatigue process.In addition,the fracture of specimens were observed by using scanning electron microscope,which show the fracture model of magnesium alloy subjected three point bending is quasi-cleavage fracture.According to fracture morphology and microscopic metallographic structure of crack,crack propagation path and fracture mechanism were analysed and some Suggestions for the improvement of three point bending low cycle fatigue properties were put forward.更多还原