压头晶体各向异性对纳米压痕变形机理的影响  

Influences of indenter's crystalline anisotropy on deformation mechanism of nanoindentation

作　　者：李生飞[1] 倪玉山[1] 

机构地区：[1]复旦大学力学与工程科学系,上海200433

出　　处：《功能材料》2014年第21期21089-21093,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(10576010)

摘　　要：为了研究压头晶体各向异性对纳米压痕变形机理的影响,用多尺度准连续介质(QC)法模拟了不同晶向的Ni压头与Ag薄膜的纳米压痕过程,对比不同晶向的压头在薄膜的弹-塑性转变点和最大载荷时薄膜中的原子滑移带,发现压头的晶向是决定薄膜开启原子滑移系的难易的关键因素。研究了压头在不同晶向下纳米压痕过程中Ag薄膜的变形机理,发现薄膜中原子滑移大都由压头拐角处触发。用RiceThomson位错模型计算得到压头表面正应力和切应力的分布图,借助应力分布图讨论了薄膜原子滑移的开启机理。Quasicontinuum method was applied to investigate the deformational mechanism of single crystal Ag thin film with Ni indenter in different crystal direction.The influences of anisotropic behavior of Ni indenter on the load necessary for first dislocation emission and contact stress distribution were studied in the nanoindenta-tion deformation process.Results show that the sharp of the load-displacement curves are due to the collective dislocation activities.The indenter with different crystal direction can greatly influence the load necessary for first dislocation emission and contact stress distribution.The simulation results are also compared and analyzed with the Rice-Thomson dislocation model.

关 键 词：多尺度 纳米压痕 晶体各向异性 变形机理 

分 类 号：TB30[一般工业技术—材料科学与工程] TB34