两种不同形状压头与单晶铜基体间接触力和摩擦力的纳观分析

发布时间：2018-01-30 19:17

本文关键词： 半球形压头圆锥形压头接触力摩擦力分子动力学　出处：《摩擦学学报》2015年03期 　论文类型：期刊论文

【摘要】：在考虑单晶铜基体弹塑性形变和晶体各向异性情况下,基于原子尺度,采用混合势函数(EAM和Morse)和Verlet算法动态模拟了半球形和圆锥形两种不同形状压头与单晶铜基体的黏着接触和滑动摩擦过程,分析了接触力和摩擦力对单晶铜基体内失效原子变化情况.研究表明:当压头下压位移为0.9 nm时,由于半球形压头比圆锥形压头底部表面积大,导致半球形压头与基体之间的引力更大而更易产生黏着接触现象.在下压接触过程中,与半球形压头相接触的基体内出现位错原子长大成位错环,而与圆锥形压头相接触的基体未出现此位错环现象,但位错原子数均随压深的增加而增多;在滑动过程中,因半球形压头对基体的摩擦力和法向力比圆锥形压头对基体的摩擦力和法向力大,使得半球形压头比圆锥形压头正前方堆积的位错原子数多,但均随滑动距离的增加而增多.
[Abstract]:Considering the elastoplastic deformation and anisotropy of single crystal copper matrix, the atomic scale is used. The adhesion contact and sliding friction process between two different shapes of pressure head and single crystal copper matrix were simulated by mixing potential functions (EAM and Morse) and Verlet algorithm. The effect of contact force and friction force on the failure atoms in single crystal copper matrix is analyzed. The results show that when the pressure displacement of the head is 0.9 nm, the surface area of the bottom of the head is larger than that of the cone head. The gravitational force between the hemispherical pressure head and the matrix is stronger and it is easier to produce adhesive contact phenomenon. In the process of downward pressure contact, dislocation atoms grow up into dislocation rings in the matrix in contact with the hemispherical pressure head. However, the dislocation ring did not appear in the matrix in contact with the cone head, but the number of dislocation atoms increased with the increase of the pressure depth. In the process of sliding, the friction force and normal force of the hemispherical head on the matrix is larger than that of the conical head on the matrix, which makes the hemispherical head have more dislocations than the conical head. However, both of them increase with the increase of sliding distance.
【作者单位】：福州大学机械工程及自动化学院;浙江师范大学工学院;
【基金】：国家自然科学基金项目(51205062;51175085)资助~~
【分类号】：TG146.11
【正文快照】： The project was supported by the National Natural Science Foundation of China(51205062 and 51175085).atoms on the surface of the substrate contacted with a conical indenter is smaller than the one contacted with a semi-spherical indenter.2003年,Walraven

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