晶粒尺寸对多晶铜接触力学特性的影响  

Influences of Grain Sizes on Contact Mechanics Properties of Polycrystalline Coppers

作　　者：林起崟 张瑜寒[1,2] 洪军 王晨[1,2] 张宁静 LIN Qiyin;ZHANG Yuhan;HONG Jun;WANG Chen;ZHANG Ningjing(Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System,Xi'an Jiaotong University,Xi'an,710049;Institute of Design Science and Basic Components,Xi'an Jiaotong University,Xi'an,710049)

机构地区：[1]西安交通大学现代设计及转子轴承系统教育部重点实验室,西安710049 [2]西安交通大学设计科学与基础部件研究所,西安710049

出　　处：《中国机械工程》2021年第19期2312-2320,共9页China Mechanical Engineering

基　　金：国家自然科学基金(51975457);国家自然科学基金重点项目(51635010)。

摘　　要：为研究晶粒尺寸对材料接触力学特性的影响,考虑多晶铜基体弹塑性变形情况,基于分子动力学方法,在原子尺度下模拟了金刚石压头与不同晶粒尺寸的铜基体的接触与分离过程。研究结果表明:在不同晶粒尺寸下,多晶铜黏着接触过程中的最大黏着力基本保持不变,最大法向接触力随晶粒尺寸的减小表现出先增大后减小的趋势。纳米硬度和接触刚度分别与接触过程中的塑性能和弹性能的变化相关,且纳米硬度与接触刚度的变化总体成负相关。最后,采用公共近邻分析方法研究了多晶铜基体弹塑性变形过程,研究发现晶界数量对材料的纳米硬度有重要影响,并进一步影响其接触力学特性。In order to study the influences of the grain sizes on the contact mechanics properties of the materials,the contact and separation processes of the diamond indenter and the copper substrate with different grain sizes were investigated at the atomic scale,where the molecular dynamics method was utilized and the elastoplastic deformations of the polycrystalline copper substrates were considered.The results show that with different grain sizes,the maximum adhesion force during the adhesive contact processes of the polycrystalline coppers remains unchanged basically,and the maximum normal contact force shows a trend of first increasing and then decreasing with the decrease of the grain sizes.Moreover,the nano-hardness and contact stiffness are respectively related to the changes of the plastic energy and elastic energy during the contact processes,and the change of the nano-hardness possesses a negative relation with that of the contact stiffness generally.Finally,based on common neighbor analysis method,a study of the elastoplastic deformation processes of the polycrystalline copper substrates was conducted,and it is found that the number of grain boundaries strongly influences the nano-hardness of materials,and then further affects the contact mechanics properties.

关 键 词：多晶铜 纳米硬度 接触刚度 接触力学 弹塑性变形 

分 类 号：TH117.3[机械工程—机械设计及理论]