发动机挺柱沉积类金刚石薄膜的工艺及性能

摘要

采用磁控溅射法,以Cr、Ti和石墨为靶材,Ar、N2和CH4为溅射气体,在材料为20CrMo的发动机挺柱上利用多层梯度复合技术沉积了低摩擦类金刚石(DLC)薄膜复合层CrTi/CrTiN/CrTiC/DLC.该薄膜复合层的纳米压痕硬度高达13 GPa,结合力为50 N,表面粗糙度为0.398 nm.在SRV-IV微动摩擦磨损试验机上进行耐磨损试验后,DLC复合薄膜挺柱的磨损率为渗碳挺柱的1/6.该研究技术具有自主知识产权,实现了挺柱批量化覆膜加工,并有望在发动机主要摩擦副上推广应用.%A low-friction multilayered diamond-like carbon (DLC) film with gradient structure of CrTi/CrTiN/CrTiC/DLC was deposited on tappet made of 20CrMo by magnetron sputtering of Cr,Ti,and graphite targets in Ar/N2/CH4 atmosphere.The composite thin film features hardness up to 13 GPa,bonding strength 50 N,and surface roughness 0.398 nm.The wear rate of the sputtered tappet is 1/6 of that of a carburized one after testing by SRV-IV fretting tribometer.The bulk thin film processing of tappets by using the technology with independent intellectual property rights has been realized,showing a promising use in manufacturing main friction couples of engines.