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采用准连续介质多尺度方法模拟面心立方金属铝单晶薄膜的纳米压痕变形过程.对薄膜分别采用三种不同的晶体取向(分别为x[111],y[10],z[2];x[2],y[111],z[10];x[10],y[001],z[0]),得到载荷-位移响应曲线.加载过程中,对晶体内部变形比较剧烈的部分画出原子图,并从微观角度分析产生剧烈变形的原因.结果表明,薄膜变形的微观机理因其晶体取向的不同而不同.在x[111],y[10],z[2]取向下,压头下压方向和晶体密排面平行,薄膜内部的主要变形机理为晶面滑移产生位错成核.该情况下材料的硬度较大,材料z方向位移较大;在x[2],y[111],z[10]取向下,压头下压方向与晶体密排面垂直,薄膜内部的主要变形机理为孪生变形.该情况下材料硬度最大,z方向位移也最大;在x[10],y[001],z[0]取向下,压头下压方向与晶体密排面呈一定角度,薄膜内部的变形机理为晶体层先滑移产生一小段位错,之后随着加载的进行在薄膜内部出现孪晶.该情况下材料硬度最小,z方向位移也最小.
The quasi-continuous media multi-scale method was used to simulate the nano-indentation deformation of the face-centered cubic aluminum metal single crystal films. Three different crystal orientations (x [111], y [10], z [10 Load response curves are obtained from the following equations: [2]; x [2], y [111], z [10]; x [10], y [001], z [0] In the process, the atomic map is drawn on the part of the crystal whose internal deformation is relatively violent, and the reason of the violent deformation is analyzed from the microscopic point of view.The results show that the micro-mechanism of the film's deformation is different due to its crystal orientation.In x [111], y [10], z [2] orientation, the direction of pressing head parallel to the crystal surface, the main deformation mechanism for the film surface dislocation nucleation occurs. In this case the hardness of the material And the displacement in z direction is larger. Under the orientation of x [2], y [111], z [10], the direction of pressing indenter is perpendicular to the crystal facet. The main deformation mechanism in the film is In the case of x [10], y [001], z [0] orientation, the direction of the pressing of the indenter is the same as that of the crystal dense surface Angle, the film's internal deformation mechanism for the crystal To generate a short slip dislocation occurs after loading with twins inside the film. In this case the minimum material hardness, z-direction displacement is minimal.