摘要
对β-Si3N4基体表面DLC薄膜压痕过程进行分子动力学模拟。压入过程模拟采用刚性球形压头与Tersoff势函数,考虑薄膜密度、膜厚、压入深度和基体属性对压痕过程的影响。模拟结果显示:薄膜抗压变形能力随着薄膜密度增加而变强,随着薄膜厚度增加而变弱;随压入深度增加,接触区内原子平均势能增加并转化为动能,导致温度升高,DLC膜中sp3键比例和配位数为5原子数增加,薄膜硬度增加。β-Si3N4基体属性对薄膜压痕特性产生影响,高硬度基体表面DLC膜的抗压变形能力更强,但随薄膜厚度增加其影响逐渐减弱。
The nano-indentation mechanisms for DLC films on 13-Si3 N4 substrate were investigated by molecular dynamic simulation. The rigid ball indenter and Tersoff potential function were used and the effects of the film density, film thick- ness, indentation depth, and substrate characteristics were considered. The results show that the compressive deformation capacity of the film is strengthened with the increasing film density, while weakened with the increasing film thickness. During indentation processes ,the average atom potential energy transfers to kinetic energy and promotes the increasing of temperature in the contact area. Accordingly the number of spa bond and 5-coordinated atoms, also the computed hardness value of film are increased. The hardness of substrate orientation of β-Si3N4 affects the DLC film characteristics while the effects are weakened at higher thickness. The harder substrate will be better to the compressive deformation capacity of thin DLC films.
出处
《润滑与密封》
CAS
CSCD
北大核心
2012年第9期10-14,27,共6页
Lubrication Engineering
基金
国家自然科学基金项目(NSFC50875058)
