Improving tribological performance of cemented carbides by combining laser surface texturing and W-S-C solid lubricant coating

Abstract

High tool wear is common during the dry machining of austenitic steels with cemented carbide tools. Surface modification is an alternative way to improve tribological performance of cemented carbides. In this paper, microscale textures were made on the surfaces of cemented carbides with a Nd:YAG laser. The W-S-C solid lubricant coatings were sequentially deposited on cemented carbide surfaces. Dry sliding tests were performed against austenitic steel balls in the ambient air. The synergic effect of microscale textures and W-S-C solid lubricant coatings on the tribological performance of the cemented carbides was studied. Results show that the microscale textured cemented carbides show lower friction than the untextured cemented carbides. The deposited W-S-C solid lubricant coatings combined with surface textures with proper groove density are more effective in improving tribological properties than that of textured surfaces. The main mechanism of textures is to capture wear debris in dry sliding condition. In addition, the reserved lubricant coating between the grooves contributes to the sufficient supply of lubricant within the contact zone. It is suggested that deposition of W-S-C solid lubricant coating on the textured surface is a promising method for improving the friction and wear performance of cemented carbides.