ABSTRACT

Considering the elastoplastic deformation of a single-crystal copper substrate, based on the atomic scale, a mixed potential function (EAM and Morse) and the Verlet algorithm were used to simulate the adhesion contact and separation process between a hemispherical diamond indenter and a single-crystal copper substrate at low temperatures. The influences of the temperature on the micro/nanomechanical properties of the material surface and on the mechanism of the subsurface deformation process were analysed. The results show that as the simulated temperature decreases, the time for adhesion to occur is delayed, and the adhesion forces increase slightly. While the indenter is being pressed, the temperature affects the generation and interaction of the dislocations in the substrate. As the temperature decreases, a large number of dislocations in the substrate are generated and then relatively reduced, and the load on the indenter fluctuates. A calculation of the mechanical properties of the material found that the contact stiffness was related to the elastic recovery energy. A smaller elastic recovery energy leads to a greater contact stiffness; thus, the indentation hardness is related to the plastic deformation energy. An increased plastic deformation energy results in a decreased indentation hardness.

摘要

考虑单晶铜基板的弹塑性变形，基于原子尺度，采用混合势函数（EAM和Morse）和Verlet算法模拟半球​​形金刚石压头与单晶压头的粘附接触和分离过程。低温下的水晶铜基板。分析了温度对材料表面微纳力学性能的影响以及对亚表面变形过程机理的影响。结果表明，随着模拟温度的降低，粘附发生的时间有所延迟，粘附力略有增加。当压头被压制时，温度会影响基体中位错的产生和相互作用。随着温度的降低，基体中产生大量位错，然后相对减少，压头负荷波动。对材料力学性能的计算发现，接触刚度与弹性恢复能有关。较小的弹性回复能导致较大的接触刚度；因此，压痕硬度与塑性变形能有关。增加的塑性变形能导致降低的压痕硬度。压痕硬度与塑性变形能有关。增加的塑性变形能导致降低的压痕硬度。压痕硬度与塑性变形能有关。增加的塑性变形能导致降低的压痕硬度。