Diamond tools have the characteristics of high hardness, high compressive strength, good thermal conductivity and wear resistance, etc.The above characteristics of diamond tools are determined by the crystal state of diamond.In diamond crystals, four valence electrons of carbon atoms are bonded according to tetrahedral structure, and each carbon atom forms covalent bonds with four adjacent atoms, thus forming the structure of diamond. This structure has strong binding force and orientation, thus making the diamond extremely hard.Because the structure of polycrystalline diamond (PCD) is a sintered fine-grain diamond with different orientation, its hardness and wear resistance are still lower than that of single-crystal diamond, although the mixture is added.However, because PCD sintered body is isotropic, it is not easy to crack along a single cleavage surface.
Main indicators:
1.The hardness of PCD can reach 8000HV, which is 8 ~ 12 times of the hard alloy;
2.The thermal conductivity of PCD is 700W/mK, which is 1.5 ~ 9 times of cemented carbide, even higher than PCBN and copper, so PCD tool heat transfer quickly;
3.The friction coefficient of PCD is generally only 0.1 ~ 0.3 (the friction coefficient of carbide is 0.4 ~ 1), so PCD tool can significantly reduce the cutting force;
4.The thermal expansion coefficient of PCD is only 0.9×10^-6 ~ 1.18×10^-6, only equivalent to 1/5 of the cemented carbide, so PCD tool thermal deformation is small, high processing accuracy;
5.PCD tools and non-ferrous and non-metallic materials between the affinity is very small, in the process of processing chip is not easy to stick on the tip of the knife to form a chip tumor.
Beijing Demina manufacturing BT-150H can grind PCD inserts with good finish through constant pressure grinding and flexible feed.
