单晶硅表面等离子体基离子注入碳纳米薄膜的摩擦学特性

用等离子体基离子注入(PBII)技术在单晶硅表面制备了碳纳米薄膜,考察了薄膜在不同载荷及速度下同Si3N4球对摩时的摩擦学性能,并采用扫描电子显微镜观察分析了磨痕表面形貌.结果表明,所制备的碳纳米薄膜光滑致密,为高硬度富弹性的类金刚石碳(DLC)膜,薄膜通过C-Si键合作用而同硅片表面形成牢固结合,且成分及结构呈现某种梯度变化特征,单晶硅经改性后摩擦学性能大幅度改善:在低载荷(0.5 N)下其耐磨寿命达3 h以上,摩擦系数处于0.10～0.30之间,磨痕不明显;在高载荷(4 N)下其耐磨寿命及摩擦系数(0.03～0.20之间)均明显降低.这是由于较高载荷或滑动速度导致DLC薄膜石墨化加剧所致.

Tribological Properties of DLC Nanolayer on Si Prepared by Plasma-Based Ion Implantation

Diamond-like carbon nanofilm was prepared on single crystal Si wafer by plasma-based ion implantation (PBII). The friction and wear properties of the resulting DLC film sliding against Si_3N_4 ball at various loads and velocities were measured on a universal reciprocating friction and wear tester, and the wear track morphologies were observed on a scanning electron microscope. It was found that a smooth and compact diamond-like carbon film with a thickness below 40 nm was formed on the Si surface by the PBII, which contributed to significantly improving the friction and wear behavior of the Si substrate. The excellent wear resistance of the DLC film conformed well to its wear track morphology as well. Namely, the DLC film was characterized by slight adhesion and scuffing as it slid against the ceramic ball even at a large load of 4 N, but the bare Si substrate was dominated by severe adhesion and scuffing even at a load as small as 0.5 N. Moreover, the friction coefficient and life of the DLC film decreased considerably with increasing load or sliding velocity, which was attributed to the strengthened graphitization of the DLC film thereat.