Dry wear behavior of identical tetrahedral amorphous carbon nanofilms on sintered composites and metal substrate with varying load bearing capacities

Abstract

Diamond-Like Carbon (DLC) coating is an effective surface treatment method for improving the tribological properties of machine elements and tool materials. Among them, the tetrahedral amorphous carbon (ta-C) coating has recently received much attention due to its high hardness and good heat resistance. When characterizing friction and wear patterns related to the lifetime and cost, the thickness of the ta-C coating and the type of substrates play an important role. In this paper, ta-C coatings of two thicknesses are deposited on 304 stainless steel (SS) and cemented carbide (WC–Co), which have significant differences in mechanical properties, through filtered cathodic vacuum arc (FCVA) equipment. After ta-C coating on substrates, the tribological properties of each sample are investigated. As a result, compared to bare materials, ta-C-coated materials have a reduced coefficient of friction and improved wear resistance. However, as the base material is softer, tearing occurs in a thin coating so that a thicker ta-C coating might improves the tribological properties. Since thicker ta-C coatings do not always improve tribological properties, the efficiency can be increased by customizing the ta-C coating thickness according to the substrate layer material.

Keywords

• DLC coating
• ta-C
• 304 SS
• WC-Co alloy
• Wear
• Friction