基于多尺度方法的纳米Cu薄膜摩擦过程中压头深度与速度效应研究

发布时间：2018-01-19 09:35

  本文关键词： 桥域法 定量化统计 纳米摩擦 位错　出处：《功能材料》2017年09期 　论文类型：期刊论文

【摘要】：采用桥域方法(bridging domain method)对纳米尺度下Cu薄膜表面摩擦过程进行模拟,主要对不同压头压入深度和摩擦速度下的模拟结果进行对比分析。对摩擦阻力和系统变形能的对比分析表明,压深增大使得摩擦阻力和变形能显著增加,而摩擦速度增大对二者并无显著影响;对位错原子数目的统计分析表明,压深变化对摩擦过程中不全位错和全位错的发生具有明显影响,表现为不全位错和全位错原子数目随压深增加而显著增加;定量化分析位错、孪晶等不同变形机制对总应变的贡献比重表明,压深变化对摩擦过程中不同变形机制的应变贡献影响有差异,主要表现为FCC原子应变贡献随压深增加而降低,位错、孪晶原子应变贡献受压深变化影响较小。摩擦速度变化对摩擦过程中不全位错、全位错的发生以及不同变形机制的总应变贡献均无明显影响,这与不同摩擦速度下摩擦阻力、变形能的分析结果一致。
[Abstract]:The surface friction process of Cu films at nanoscale was simulated by bridging domain method. The simulation results of different indentation depth and friction velocity are compared. The comparison of friction resistance and system deformation energy shows that the increase of pressure depth makes friction resistance and deformation energy increase significantly. However, the increase of friction velocity has no significant effect on them. The statistical analysis of the number of dislocation atoms shows that the variation of pressure depth has a significant effect on the occurrence of incomplete dislocation and total dislocation in the friction process, which shows that the number of incomplete dislocation and total dislocation atom increases significantly with the increase of pressure depth. Quantitative analysis of the contribution of different deformation mechanisms, such as dislocations and twins, to the total strain shows that the effect of the depth variation on the strain contribution of different deformation mechanisms in friction process is different. The results show that the strain contribution of FCC atom decreases with the increase of compression depth, while the dislocation and the strain contribution of twin atom are less affected by the variation of compression depth, and the variation of friction velocity has less effect on the incomplete dislocation in the friction process. The occurrence of total dislocation and the total strain contribution of different deformation mechanisms have no obvious influence, which is consistent with the analysis of friction resistance and deformation energy at different friction speeds.
【作者单位】： 复旦大学航空航天系;
【基金】：国家自然科学基金资助项目(11572090)
【分类号】：TB383.2;TG146.11
【正文快照】： 0引言随着实验操作与工业生产的精度要求日益提高,微纳米尺度精密仪器在表面科学、微纳机电系统等领域的应用日益广泛。接触与摩擦问题一直是材料设计与性能改进方面的主要研究课题之一,研究材料微纳米尺度下的摩擦学行为,揭示摩擦过程中材料的微观变形机制与宏观力学性能的内，

本文编号：1443572