Materials Today Communications ( IF 3.7 ) Pub Date : 2020-01-20 , DOI: 10.1016/j.mtcomm.2020.100946 Wei Shao , Yefei Zhou , Zhijun Shi , Lixiang Rao , Tianshi Hu , Xiaolei Xing , Qingxiang Yang
In this paper, the structures of diamond-like carbon (DLC) films doped with carbide forming elements Me (MeTi, V, Cr, Zr, Nb, W) were designed firstly by molecular dynamics method. Then, the residual stress and mechanical properties of Me-DLC films were calculated. Meanwhile, the effect of doping carbide forming elements Me on DLC films were analyzed, which indicates the mechanism that the residual stress is decreased. The results show that the residual stress in Me-DLC films is compressive stress. With the increase of Me content, they are decreased firstly and then increased. Meanwhile, the smaller residual compressive stress of the DLC films is, the better their comprehensive mechanical properties are. By the structural analysis, it is found that the carbide forming elements Me are easily combined with the tri-coordinate C to increase the tetra-coordinate C content, which might affect the residual compressive stress. By the bond length and bond angle distribution analysis, it is observed that the CC bond length is relaxed and the CCC bond angle is deformed. By ELF analysis, it is found that a weak covalent bond is formed between the Me atom and the C atom, which lowers the bonding strength.
中文翻译:
分子动力学模拟碳化物形成元素Me对DLC薄膜残余应力和力学性能的影响
在本文中,掺杂有碳化物形成元素Me(Me的类金刚石碳(DLC)膜的结构首先通过分子动力学方法设计了Ti,V,Cr,Zr,Nb,W。然后,计算了Me-DLC膜的残余应力和力学性能。同时,分析了掺杂碳化物形成元素Me对DLC薄膜的影响,表明了残余应力降低的机理。结果表明,Me-DLC薄膜的残余应力为压应力。随着Me含量的增加,它们先降低然后升高。同时,DLC膜的残余压缩应力越小,其综合机械性能越好。通过结构分析,发现碳化物形成元素Me容易与三坐标C结合以增加四坐标C含量,这可能影响残余压缩应力。C键的长度被放宽且C Ç C键角变形。通过ELF分析,发现在Me原子和C原子之间形成弱的共价键,这降低了键合强度。