CBN - Hardness

Because the hardest diamond carbon has a strong chemical affinity, so it is not suitable for machining alloy. That way, people developed a cubic boron nitride (CBN), it made the tool, its use more widely. CBN for its hardness, the diamond came in second place after. In other words, it is in a high temperature of 1000 degrees Celsius 25 degrees Celsius while still maintaining the hardness of cemented carbide.
And polycrystalline  Polycrystalline diamond (PCD) as cubic boron nitride (CBN) high strength comes from its intergranular key. Coupled with hardness and toughness are very good carbide substrate, it made knives, cutting large high hardness in the deep  synthetic diamond  materials, can withstand significantly cutting forces. Intergranular bond also provides high impact strength, which is in continuous intermittent cutting section when necessary. CBN-layer and the carbon material in, and the ceramic has better thermal conductivity, in the turning and milling, it is compared with carbide cutting tools or thermally conductive ceramic cutting tool easier.
In the processing of large hardness, high toughness and wear serious material, the cutting  Polycrystalline diamond  will result in a high temperature cutting material surface. In this case, the cutting generally will reduce the hardness of the material, soften. CBN-inserts will not happen. Even in a high temperature of 1000 ° C of the cutting edge is not only able to maintain the original strength and hardness, resistance to oxidation and still, and will not, such as iron, nickel and cobalt and other metal chemical reaction.