High Thermal Stability pcbn Cutting Tool Tungsten Carbide cnc Insert
Main Properties of PCBN Tool Materials
High hardness and wear resistance
The microhardness of CBN single crystal is hv8000-9000, which is the second highest known material. The hardness of PCBN composite is hv3000-5000. Therefore, it has higher wear resistance than cemented carbide and ceramics when it is used to process high hardness materials, which can reduce the size deviation or size dispersion in the processing of large parts, especially in the equipment with high degree of automation, which can reduce the auxiliary time of tool change and adjustment, so that its efficiency can be brought into full play.
High thermal stability and high temperature hardness
The heat resistance of CBN can reach 1400-1500℃, and the hardness at 800℃ is the hardness of Al2O3 / TiC ceramics at room temperature. Therefore, when the cutting temperature is high, the material to be processed will be softened, and the hardness difference between the material and the tool will increase, which is conducive to the cutting process, but has little impact on the tool life.
High chemical stability
CBN has a high oxidation resistance, does not produce oxidation phenomenon at 1000 ℃, and does not have chemical reaction with iron materials at 1200-1300 ℃, but it will produce hydrolysis with water at about 1000 ℃, resulting in a large number of CBN being worn. Therefore, when using PCBN tool for wet cutting, it is necessary to select the type of cutting fluid. In general, the life of PCBN tools is not significantly improved by wet cutting, so dry cutting is often used when PCBN tools are used.
Good thermal conductivity
The thermal conductivity of CBN material is lower than that of diamond but much higher than that of cemented carbide, and with the increase of cutting temperature, the thermal conductivity of PCBN tool is increasing, so the heat at the tip of the tool can be transferred out quickly, which is conducive to the improvement of workpiece processing accuracy.
