Performance of PVD MoS2/Zr-coated carbide in cutting processes

MoS2/Zr composite coatings were deposited on the surface of YT15-cemented carbide. Microstructural and fundamental properties of these coatings were examined. Dry cutting and sliding wear tests on hardened steel were carried out with these coated tools. Results showed that PVD MoS2/Zr composite coatings onto the cemented carbide substrate show higher hardness and better adhesion with the substrate in comparison with the pure MoS2 coatings, and exhibit decreased friction coefficient to that of the uncoated carbide in sliding wear tests. Cutting speeds were found to have a profound effect on the wear behaviors of MoS2/Zr-coated tools. In case of low-speed cutting, the MoS2/Zr-coated tools showed much better cutting performance compared to the uncoated tools, the MoS2/Zr coatings on the rake face can be acted as lubricating additives between the tool–chip sliding couple during cutting processes, and contribute to the decrease of the tool wear; while in high-speed cutting processes, there are quite a number of cracks on the coating owing to the elevated cutting temperature, which may initiate the loss of the coating from the tool face, and lead to the increase of the tool wear.