Effect of the plasma irradiation on the friction of carbon fiber

Abstract

Carbon fibers are expected to be low friction materials. By knitting carbon fibers, it is assumed to be easier to manufacture low friction area rather than several carbonaceous coating such as DLC. However, friction coefficient of carbon fibers is not clarified and it is required to obtain low friction surface of carbon fibers with some surface modification technology. Ar and N 2 plasma irradiation was utilized to reduce the friction coefficient of carbon fibers. Static friction coefficient of carbon fiber was approximately 0.4 against SUJ2 pin, Si3N4 pin, DLC coated stainless steel pin and carbon fibers itself, and the static friction coefficient depended on normal load. On the other hand, kinetic friction coefficient of carbon fiber was approximately 0.2 against all of mating materials. They did not depend on normal load so much. After the 10 minute irradiation of Ar and N2 plasma, static and kinetic friction coefficients of carbon fibers decreased from 0.4 to 0.3. Kinetic friction coefficient of Ar and N2 plasma irradiated carbon fiber decreased from 0.2 to 0.15. © 2013 The Japan Society of Mechanical Engineers.