The Coating And Substrate On The Pvd Coating Cemented Carbide Cutting Tools High Speed Turning The Influence Of High Temperature Alloy

The high-speed, effectively machining of material nickel-base superalloy and other difficult-to-cut materials is a major task for the tool industry. Novel coating materials and the matchable cemented carbide substrate is an important way to meet this request.AlTiN and TiAlSiN coatings were deposited onto two kinds of cemented carbides with different cobalt content by cathodic arc-evaporation. The high temperature hardness of the cemented carbide substrate, nano-hardness of the coated cemented carbide, adhesive force between the cenmented carbide substrate and the coating, and the thermal property of the cemented carbide substrate were detected by high tempera hardness tester, nano-indentation tester, Micron scratches instrument, and hotdisk thermal constant analyzer, respectively. The influence of coating and the substrate cobalt content on the basic mechanical and thermal properties of coated cemented carbide cutting tool was investigated. Carried out both experiments and Finite Element Simulation of high speed turning nickel-base superalloy using PVD coated cemented carbide tools with different materials. Revealed the effects of the basic mechanical and thermal property on the cutting process and tool failure mechanism of coated carbide tools. The results as follows,1. The nano-hardness of the PVD TiAlSiN coating is higher than which of PVD AlTiN coating, and for the adhesive force of the coating and the substrate, PVD TiAlSiN is higher than AlTiN coating either;2. With the cemented carbide substrate cobalt content decreased from10wt.%to6wt.%, the thermal conductivity of the substrate increased from62.75W·m℃to84.57W·m℃and the high temperature Vickers hardness elevated by about10%at the same temperature。 The high temperature of the substrate decreased as temperature increase;3. FEM simulation result shows, when using the same coating, the higher of the substrate thermal conductivity, the lower of the tool cutting temperature, and the smaller of the cutting temperature gradient; for using the same substrate, the higher of the coating thermal conductivity, the higher of the tool cutting temperature, and the more great of the cutting temperature gradient; 4. The tool failure mechanisms of both CC10-A insert (10wt.%Co cemented carbide substrate+AlTiN coating) and CC6-A insert (10wt.%Co cemented carbide substrate+AlTiN coating) when wet-type high-speed turning superalloy are adhesive wear and oxidation wear of the cutting edge accompanied by adhesive wear and abrasive wear of the flank face. Cutting edge and flank face of CC10-A insert (10wt.%cobalt substrate) wear seriously, while CC6-A insert wear steadily and slowly, and the cutting life of the tool increase about3times when the cobalt content of substrate decreased from10wt.%to6wt.%.5. The cutting life of PVD TiAlSiN coated cemented carbide tool is longer than PVD AlTiN coated cemented carbide. The tool failure mechanism of VC6-A (6%wt.%Co cemented carbide substrate+AlTiN coating) tool is oxidation wear and diffusion wear followed by tearing and stripping of build-up edge (BUE) caused by adhesive wear which occurred under high temperature and high pressure conditions. Insert failed by the uniform adhesive wear at rake face near the cutting edge and flank groove wear accompanied by BUE bond stripping while for VC6-T (6%wt.%Co cemented carbide substrate+TiAlSiN coating) tool, the failure mechanism is forming and stripping of BUE caused by adhesive wear which occurred under high temperature and high pressure conditions.