Study on Crystallographic Orientation Effect on Surface Generation of Aluminum in Nano-cutting.
Study on Crystallographic Orientation Effect on Surface Generation of Aluminum in Nano-cutting.
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纳米切削中铝表面生成的晶体取向效应研究
DOI：
10.1186/s11671-017-1990-3
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发表时间：
2017-12
影响因子：
--
通讯作者：
Zhang X
中科院分区：
文献类型：
--
作者：
Xu F;Fang F;Zhu Y;Zhang X
材料的尺寸效应等材料特性是纳米材料切削加工中不可忽视的重要因素之一。采用分子动力学模拟方法研究了单晶材料的各向异性对纳米切削的影响。结果表明，塑性变形的尺寸效应是基于不同的塑性载体，如孪晶、层错和位错。最小未切削切屑厚度取决于切削方向，当切削方向为{110}时甚至获得负值<001>。它还确定材料变形和去除机制（例如，剪切、挤压和摩擦机制），同时减小未切割的切屑厚度。当材料发生剪切变形时，主剪切区从滞止点或滞止区尖端开始扩展。当材料受到挤压和摩擦变形时，第一变形区几乎平行于切削方向，并从切削刃底部开始扩展，与第三变形区合并。生成的表面质量与晶体取向和最小未切屑厚度有关。{110}<001>、{110}<1-10>和{111}<1-10>的切削方向的最小未切削切屑厚度相对较小，与其他切削方向相比具有更好的表面质量。
The material characteristics such as size effect are one of the most important factors that could not be neglected in cutting the material at nanoscale. The effects of anisotropic nature of single crystal materials in nano-cutting are investigated employing the molecular dynamics simulation. Results show that the size effect of the plastic deformation is based on different plastic carriers, such as the twin, stacking faults, and dislocations. The minimum uncut chip thickness is dependent on cutting direction, where even a negative value is obtained when the cutting direction is {110}<001>. It also determines the material deformation and removal mechanism (e.g., shearing, extruding, and rubbing mechanism) with a decrease in uncut chip thickness. When material is deformed by shearing, the primary shearing zone expands from the stagnation point or the tip of stagnation zone. When a material is deformed by extruding and rubbing, the primary deformation zone almost parallels to the cutting direction and expands from the bottom of the cutting edge merging with the tertiary deformation zone. The generated surface quality relates to the crystallographic orientation and the minimum uncut chip thickness. The cutting directions of {110}<001>, {110}<1-10>, and {111}<1-10>, whose minimum uncut chip thickness is relatively small, have better surface qualities compared to the other cutting direction.