挤压镁合金AZ31D的超高周疲劳行为研究  

Super-long life fatigue behavior of extruded AZ31D magnesium alloy

作　　者：尹树明[1] 王春晖[1] 赵述哲[1] 成泰民[1] 

机构地区：[1]沈阳化工大学,辽宁沈阳110142

出　　处：《轻金属》2013年第7期54-56,共3页Light Metals

基　　金：国家自然科学基金(批准号:10647138)

摘　　要：对挤压镁合金AZ31D进行了超声疲劳实验。结果表明在超高周范围,该材料的应力-寿命曲线呈连续下降型。在109周时材料的疲劳强度为90±5MPa;疲劳极限与抗拉强度之比约为0.3。疲劳裂纹主要萌生于表面或亚表面的拉伸孪晶,也有个别样品的疲劳裂纹萌生于样品内部的Al-Mn相。Ultrasonic fatigue testing had been conducted on extruded AZ31 D magnesium alloy. The S--N curve for this alloy appeard to have a continuous decreasing trend in the very high cycle regime. Fatigue strength at 109 cycles was 90 ＋ 5MPa. The ratio of endurance limit at one billion cycles to the tensile strength （ σ -1/σb ） was 0. 3. Fatigue crack mainly originated from the specimen surface or near surface, where deformation twins were found after cyclic loading. Fatigue cracks also initiated at sample interior where higher content of A1 and Mn were observed.

关 键 词：镁合金 超高周疲劳 裂纹萌生 拉伸孪晶 

分 类 号：TG379[金属学及工艺—金属压力加工]