Research On Properties Of Coatings Deposited On Cemented Carbide Cutting

Cemented carbide cutting tools combide the advantages of the substrate high strength and high ductility with high hardness and high wear resisting property of the coating, Increasing cutting tool wear-resistant but not reducing substrate ductility. As new coating materials and coating process is developing in the ascendant, indicating the development of coated tools will have a great potential and broad application prospects.The paper select home-made YG11C/TaCp cemented carbides as substrate, TiN and TiAlN coating were deposited by reactive magnetron sputtering. Craft of depositing TiN by the voltaic arc ionized was introduced, the paper studied how processing parameter influence on property of TiN coating. Then coating/substrate picked up the optimized processing parameter as follow: the minus bias 200V, the N2 pressure component the electric current of arc was 60A. The TiN coating deposited with above processing parameter was slick,well-structural homogeneity, high hardness, and good coating/substrate bonding properties. TiN, TiCN and ZrN coating were deposited by voltaic arc ionized with the same parameter as TiN, so the properties of coatings could be compared. Structural examinations are presented of the applied coatings and their substrate made on the optical microscope, scanning electron microscope and X-Ray diffractomer. TiN, TiCN and ZrN coating were (111) preferred orientation. Annealed coated cutting tool on 250℃and 300℃by 1 hour. The hardness of coating were advanced after annealing on 250℃, crystal grains of coating were refined after annealing 300℃. Analyse interface mechanism of coated cutting tool, we found that ZrN coating was better in bond strength and wear-resisting property.Studied how load and rotational speed influence on friction coefficient of coating, analysed abrasion mechanism by friction experiment. We learned that the friction coefficients were lower under higher load with high rotational speed than under low load with min rotational speed, and the abrasion mechanism was grain-abrasion, as well with little oxidize abrasion and adhesion abrasion. The friction coefficient of Substrate, TiN, TiCN,and ZrN coating were close under low load, the friction coefficient of ZrN was smaller than others, ZrN coating has a good abrasion resistance, as cutting tool, it has more practical significance.