Study on cutting forces and experiment of MoS₂/Zr-coated cemented carbide tool

MoS₂/Zr composite films were deposited on the cemented carbide YT14 (WC+14%TiC+6%Co) by medium-frequency magnetron sputtered coupled with multi-arc ion plating techniques. The thickness, micro-hardness, and coating/substrate adhesion strength of the coatings were tested. Surface morphologies of the composite coatings, as well as wear features, were investigated by scanning electron microscopy. Dry machining tests on hardened steel were carried out with the coated tool and uncoated YT15 tool. The variation of cutting forces for 45# hardened steel was tested by the Kistler force tester. The result shows that the cutting forces of coated tool were decreased by 25-30%, and flank wear resistance was improved by 30-35% in comparison with the uncoated YT15 tool. Through the analysis of cutting force distribution theory, the lower mean shear stress on the MoS₂/Zr- coated tool face leads to the decrease of cutting force and increase of tool wear resistance.