含中心微裂纹α-Fe拉伸与疲劳失效机理的原子模拟  

Atomistic simulation of failure mechanism forα-Fe with central crack under uniaxial tensile and fatigue loading

作　　者：袁玉全[1] 曾祥国[2] 胡燕飞[1] 

机构地区：[1]四川理工学院理学院,四川自贡643000 [2]四川大学建筑与环境学院,四川成都610065

出　　处：《陕西师范大学学报（自然科学版）》2016年第2期21-26,共6页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国防重点基金(B1520132013-1);四川理工学院科研项目(2015RC41;2015RC44);四川省教育厅科研项目(15ZB0207)

摘　　要：采用分子动力学方法研究了含(010)[101]型中心裂纹的金属α-Fe在拉伸载荷和疲劳载荷作用下裂纹扩展的微观机制。研究表明,含有此类裂纹的体心立方金属铁在单轴拉伸载荷下,其破坏机制是一个以裂尖层错和孪晶变形共同存在、伴有裂纹钝化,并最终以孪晶变形为主的过程。疲劳失效是以孪晶形变为主,全位错、不全位错、层错共同作用的破坏机制,同时发现循环加载下[11-1](-121)滑移系中孪晶形变比位错更容易发生,而且孪晶的出现,有利于减缓疲劳裂纹的扩展速度。含裂纹α-Fe变形与失效的过程,是一个位错、层错、孪晶和相变等多种微观机制共同作用的复杂过程。Molecular dynamics simulation is performed for the failure mechanism forα-Fe with（010）[101]centered pre-crack defect under uniaxial tensile and fatigue loading.The results show that the failure mechanism under uniaxial tensile loading is a process with crack blunting,stacking faults and twins formation.While under fatigue loading,the failure mechanism is twins deformation based,coupled with dislocation,partial dislocation,stacking faults.Furthermore the twin deformation occurs easier than the dislocation emission in[11-1]（-121）slip system.The study indicate that the deformation and failure process ofα-Fe with crack defect is a complicated process,which is the result that many mechanisms act together,such as dislocation,stacking faults,twin and phase transition.

关 键 词：分子动力学 中心裂纹 Α-FE 拉伸 疲劳 

分 类 号：O483[理学—固体物理]