马彬;牛海华;朱林伟;

• 1:桂林电子科技大学建筑与交通工程学院

摘要(Abstract)：

以含微裂纹缺陷的钨纳米板为研究对象,采用分子动力学方法模拟其在拉伸荷载作用下的变形破坏过程,揭示微裂纹的破坏机制以及对材料整体力学性能的影响规律。结果表明:含裂纹单晶钨纳米板的应力-应变曲线均可划分为弹性、孪晶、位错、裂纹扩展阶段,其中(010)[001]裂纹构型具有独特的相变平衡阶段。不同晶向裂纹起裂机理为(010)[001]构型裂纹沿结合能最低的相变区域交界处即初始方向起裂;(0-11)[100]构型裂纹沿BCC结构表面能最低的密排面(110)起裂。不同晶向裂纹的扩展方向在宏观意义上均与初始方向一致,(010)[001]构型裂纹沿相变后FCC结构原子的密排面(111)和(-111)开始交替扩展,裂口呈锯齿状,而(0-11)[100]构型裂纹裂口整齐平滑。(010)[001]构型裂纹的破坏形式为韧性破坏,(0-11)[100]构型裂纹的破坏形式为脆性破坏。

关键词(KeyWords)： 钨纳米板;中心裂纹;力学性能;破坏机制;分子动力学

Abstract:

Keywords:

基金项目(Foundation): 广西高校中青年教师基础能力提升项目(2017KY0194)

作者(Author): 马彬;牛海华;朱林伟;

Email:

DOI: 10.14024/j.cnki.1004-244x.20190621.002

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