摘要
在MTS万能实验机上对室温大气环境下过时效态3J21合金的疲劳行为进行研究,并采用扫描电镜(SEM)对宏观断口及微观断口进行分析。结果表明,过时效态3J21合金的疲劳裂纹呈穿晶扩展和沿晶扩展,且沿晶扩展的比例较大,疲劳裂纹萌生寿命短,扩展途径相对平直,扩展速率大,裂纹扩展抗力小,疲劳寿命低;过时效态3J21合金疲劳断口由疲劳源、疲劳裂纹扩展区和瞬断区组成。在低速扩展区,过时效态断口呈现冰糖状花样,在中速扩展区未看到长的疲劳条纹,仅发现个别短小的疲劳条纹,瞬断区可观察到二次裂纹、准解理和韧窝。
In this paper the fatigue behavior of over-aged state 3J21 alloy was studied by using MTS testing machine. The macro- graphs and micrographs of fatigue fracture were analyzed by scanning electron microscopy （SEM）. The results show that the fatigue crack growth for over-aged state alloys is transgranular and the fatigue crack initiation life is short as the proportion of growth along intercrystalline increases. The crack track is straight, the fatigue crack growth rate is fast, the fatigue crack growth resistance is low and the fatigue life is short. The fatigue fracture consists of fatigue source, fatigue crack growth area and in- stantaneously fractured area of over-aged state 3J21 alloy. In low growth area, the fatigue fracture show sugar candy pattern. In middle growth area, there were not any long fatigue striations inspected, except some small individual fatigue striations.
出处
《材料开发与应用》
CAS
2011年第4期16-19,23,共5页
Development and Application of Materials
基金
国家自然科学基金资助项目(G1999065005)
