真空环境下自然时效态2A12合金的疲劳行为  

Fatigue Behavior of Nature-aged 2A12 Alloy in Vacuum

作　　者：金晓鸥[1] 赵慧杰[2] 何世禹[2] 

机构地区：[1]黑龙江大学建筑工程学院,哈尔滨150086 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《材料工程》2006年第3期48-51,共4页Journal of Materials Engineering

基　　金：国家重点基础研究发展规划项目(G1999065005)

摘　　要：在真空拉-压疲劳实验机上对真空和室温大气环境下自然时效态2A12合金的疲劳行为进行了研究,并采用扫描电镜(SEM)分析了真空和室温大气环境对疲劳断口形貌的影响。对比两种环境下的结果表明,真空环境使疲劳寿命提高,疲劳曲线右移。在低循环应力时,真空环境中的疲劳断裂次数可比室温大气环境中的高近4倍。真空和室温大气环境下的疲劳断口均出现疲劳条纹、台阶和韧窝,且在低循环应力时出现韧窝的区域增多。真空环境下疲劳断口中台阶高度较低,疲劳条纹与韧窝较细小。本研究对真空环境影响自然时效态2A12合金疲劳行为的原因进行了讨论。The fatigue behavior of nature-aged 2A12 alloy in air and vacuum at room temperature was investigated using a vacuum tension-compression fatigue testing machine. The effect of air and vacuum on the fatigue fractures was studied by means of Scanning Electron Microscopy （SEM）. The resuits show that the fatigue life can be noticeably improved in vacuum than that in air, and the S-N curve shifts to the right in vacuum. Under lower cyclic stresses, the fatigue cycles to failure in vacuum is increased approximately 4 times than in air. Both the fractures in air and vacuum, in which fatigue striations, steps and dimples are observed and more areas with the dimples exist under lower cyclic stresses. In vacuum, the height of the steps is smaller, and the fatigue striations and dimples are finer. The reason for the effect of vacuum on the fatigue behavior of nature-aged 2A12 alloy was discussed.

关 键 词：2A12合金 疲劳 真空 

分 类 号：TG113[金属学及工艺—物理冶金]