A new composite material – low-carbon Stellite alloy reinforced with nickel-coated carbon fibers

Abstract

A group of nickel-coated carbon fiber reinforced Stellite 25 composites are produced using the hot isostatic pressing technique. The focus of this research is on obviating the problems related to the presence of carbides in Stellite alloys by substituting carbides as the main strengthening agent in Stellite alloys with nickel-coated carbon fibers. The principal reason for selecting Stellite 25 is because of its low carbon content and thereby relatively carbide free microstructure. The nickel coating is intended to eliminate any chance of carbide formation due to the possible reaction between carbon fibers and the matrix alloying additions. The tribomechanical and corrosion properties of the composites are characterized. The results show that the composites exhibit better corrosion resistance than medium-carbon Stellite alloys. The addition of carbon fibers into Stellite 25 improves its hardness and tribological properties. The wear rates of the composites are lower than that of medium-carbon Stellite alloys and comparable with that of high-carbon Stellites.