Preparation and cutting performance of WS2 soft-coated tools

Abstract

WS2 soft-coated tools were produced by medium-frequency magnetron sputtering, multi-arc ion plating, and ion beam-assisted deposition technique on the cemented carbide YT15 (WC + 15 % TiC + 6 % Co) substrates. The thickness, microhardness, surface morphologies, crystallization, and coating/substrate critical load of the coatings were tested and investigated. Dry turning tests on no. 45 quenched and tempered steel were carried out with the coated tool and uncoated YT15 tool. Cutting forces and cutting temperatures were tested, respectively. The result shows that the cutting force of WS2 soft-coated tool was decreased by 30–35 %, and the cutting temperature was reduced by 10–15 % in comparison with the uncoated YT15 tool. Through cutting force and cutting temperature theoretical analysis, the lower average shear strength of WS2 soft coating at the tool–chip and tool–workpiece interfaces leads to the decrease of cutting force and cutting temperature during cutting process. The advantage in cutting force and cutting temperature is obvious in relatively high-speed and high-temperature conditions may be because of the high temperature resistance and the oxidation resistance of WS2 soft coating which is not sensitive to high cutting temperature and high cutting speed.