TRIBOLOGICAL PROPERTIES OF a-CARBON AND CARBON NITRIDE COATINGS SLIDING AGAINST SILICON NITRIDE BALL IN THE STREAM OF NITROGEN GAS

摘要

Amorphous carbon (a-C)-based materials such as Diamond-like carbon (DLC) and carbon nitride (CN{sub}x) have been expected as promising lubricious thin hard coatings. The lubricity of the coatings is affected by environmental gases [1]. In case of CN{sub}x coatings, low friction coefficient in the order of 0.001 is provided in sliding against silicon nitride (Si{sub}3N{sub}4) in the stream of nitrogen (N{sub}2) gas [1]. The N{sub}2 lubrication with the lubricious coating is, therefore, promising as a new type of lubrication for tribological contacts in small and precise machines such as MEMS. In this paper, to introduce into practice a new lubrication technology, effect of coating procedure of CN{sub}x and a-C coatings on friction under N{sub}2 gas stream is clarified.