类金刚石碳膜的纳米划擦行为及其加载-卸载效应

Nano-scratch behaviors of diamond-like carbon (DLC) films prepared on Si substrate by rf PECVD were evaluated using a Nano Indenter® XP system with attachment of lateral force measurement (LFM). It was found that elastic recovery, elastio-plastically deforming, cracking under loading and delaminating under unloading of the film, occur successively with the increase of scratching load. Though the DLC film has not been delaminated as continuous loading until cracking of film (cracking resistance L_CL), the film was delaminated from the substrate after unloading, due to asynchronous recovery of the film and substrate. It is evident that nano-scratching test not only displays the cracking resistance charactering the cohesion strength of the film during loading, but also determines the critical load relating to adhesion of the film and the substrate during unloading.