AZ31B镁合金螺纹型缺口试样疲劳性能研究  

Study on Fatigue Behaviour of AZ31B Magnesium Alloy adoping Screw-type Notch Sample

作　　者：王海波[1] 李冬华[1] 武淑艳[2] 王永超[1] 

机构地区：[1]哈尔滨理工大学建筑工程学院,黑龙江哈尔滨150080 [2]佳木斯大学材料科学与工程学院,黑龙江佳木斯154007

出　　处：《哈尔滨理工大学学报》2010年第3期86-89,97,共5页Journal of Harbin University of Science and Technology

摘　　要：利用高频疲劳试验机对AZ31B镁合金螺纹型缺口试样疲劳性能进行了试验研究,给出了本实验条件下的S-N曲线,得到循环基数为107的疲劳极限是15.3MPa,并与相同材料光滑试样疲劳性能对比.运用扫描电镜对断口形貌进行了观察,分析了断裂机理.经分析认为:AZ31B挤压镁合金螺纹型缺口试样高周疲劳的断裂过程包括裂纹萌生、裂纹扩展、最终断裂3个阶段,疲劳源主要发生在螺纹根部,为多发性裂纹源;裂纹扩展区微观断口具有典型的解理断口形貌,断裂表现为脆性断裂.Fatigue behaviour of AZ31B magnesium alloy adopting screw-type notch sample was investigated using high frequency fatigue tester.S-N curve of AZ31B magnesium alloy under the test condition is presented and its fatigue limit based on 107 is 15.3MPa.Contrast study on fatigue behaviour between screw-type notch sample and smooth sample is conducted.Fractographs of the fatigue fracture samples are observed using scanning electron microscope and fracture mechanism is analysed.The results show that high cycles fatigue rupture of AZ31B magnesium alloy sample with screw-type notch include the crack initiation,the crack extension and the ultimate rupture.Basically,fatigue cracks initiate at the root of screw,and more than one cracks occure on one sample.The micro-fracture of crack extention zone exhibits typical morphology of cleavage rupture and rupture presents brittle feature.

关 键 词：AZ31B镁合金 疲劳极限 螺纹型缺口 断裂机理 

分 类 号：TG146.22[一般工业技术—材料科学与工程]