Development of Fluorocarbon-polymer Embedding Segment-structured DLC Film

Abstract

Diamond-Like carbon (DLC) films have been widely recognized as a tribo-coating material because of its outstanding mechanical properties. Theses properties are varied according to their preparation method and condition. In order to apply DLC films to industrial products, an appropriate film for an environmental condition should be prepared by a proper coating method. Furthermore, requirements for films are increasing recently. For example, resistance to adhesion, chemical stability, gas impermeability and water repellency are required in addition to the tribological properties. The objective of this study is a development of a multi-functionalized DLC film using segment-structured DLC (S-DLC) films. S-DLC film is a useful coating method for soft substrate. It consists of numeral small DLC segments and has grooves between the segments, which is different from the conventional continuous DLC film. In this study, a developed S-DLC film is proposed. It has fluorocarbon polymer embedded into the groove, which can improve the water repellency and lubricating ability of S-DLC film. Its tribological properties and water repellency were estimated by ball on disk tests and the contact angle of a water droplet, respectively. The friction coefficient of 0.08 is obtained, that is lower than 0.12 of continuous DLC film. The contact angle of a water droplet can be obtained about 90 degree, which is larger than 60 degree of a continuous film. From these results, multi-functionalized DLC films could have been successfully fabricated.