Molecular dynamics study on the thickness of damage layer in multiple grinding of monocrystalline silicon
Molecular dynamics study on the thickness of damage layer in multiple grinding of monocrystalline silicon
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单晶硅多次磨削损伤层厚度的分子动力学研究
DOI：
10.1016/j.mssp.2016.04.013
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发表时间：
2016-08-15
影响因子：
4.1
通讯作者：
Jin, Zhuji
中科院分区：
文献类型：
--
作者：
Guo, Xiaoguang;Li, Qiang;Jin, Zhuji
采用分子动力学模拟方法研究了多次磨削对单晶硅损伤层厚度的影响。在（0 0 1）沿着方向上进行了四次磨削加工。第一次磨削的磨削深度为20埃。随后的磨削是在第一次磨削留下损伤层的加工表面上进行加工。第二次磨削为火花熄灭过程，第三次和第四次磨削的磨削深度与前一次磨削相比增加了5埃。利用配位数（CN）、径向分布函数（RDF）和纳米压痕技术研究了一次磨削后已加工表面损伤层的结构和力学性能的变化。第一次磨削后的损伤层厚度在第二次和第三次磨削中可以稳定地减小，但在第四次磨削中会增加。因此，在第三和第四研磨之间进行两个以上的研磨步骤。一次是火花熄灭过程，另一次的磨削深度比第三次磨削增加了2埃。结果表明，电火花磨削能消除前道磨削后的回弹，促进已加工表面残余压应力的形成，提高磨削精度和质量。在不产生新的损伤结构的情况下，第一次磨削可以减小损伤层的厚度。但是，它不能无限制地减少。当损伤层厚度达到原厚度的一半时，再次磨削会产生新的损伤结构，损伤层厚度会增加。建议磨削深度小于原始损伤厚度的一半，以减少损伤层。研究结果可应用于单晶硅的超精密磨削加工中，控制损伤层厚度，提高加工质量。(C)2016爱思唯尔有限公司版权所有。
The molecular dynamic (MD) simulation of monocrystalline silicon under multiple grinding is carried out to study the effect of multiple grinding on the thickness of damage layer. Four grinding processes are conducted on (0 0 1) along direction. The depth of grinding of the first grinding is 20 angstrom. The subsequent grinding is machining on the machined surface with a damage layer left by the first grinding. The second grinding is a spark-out process and the depth of grinding of the third and fourth grinding increases by 5 angstrom compared with the previous grinding. The changes of structures and mechanical properties of the damage layer in the machined surface after the first grinding are investigated by coordination number (CN), the radial distribution functions (RDF) and nanoindentation. The thickness of the damage layer left by the first grinding can be reduced stably in the second and third grinding, but it will increase in the fourth grinding. Therefore, two more grinding steps between the third and fourth grinding are carried out. One is the spark-out process and the depth of grinding of the other increases by 2 angstrom compared with the third grinding. The results show the spark-out process can remove the springback left by the previous grinding and promote the residual compressive stress in the machined surface, which can improve the accuracy and quality of grinding. The thickness of damage layer induced by the first grinding can be reduced without new damage structures generating. However, it cannot be reduced unlimited. When the thickness of damage layer reaches half of the original thickness, a re-grinding will cause new damage structures, and the thickness of damage layer will increase. The depth of grinding is suggested to be less than half of the original damage thickness to reduce the damage layer. The research results can be applied in the ultra-precision grinding of monocrystalline silicon to control the thickness of damage layer and improve the quality of machining. (C) 2016 Elsevier Ltd. All rights reserved.