The performance characteristics of polycrystalline diamond tools

Diamond tool with high hardness, high compressive strength, thermal conductivity and good wear resistance and other characteristics, can be obtained in a high-speed

cutting machining accuracy and processing efficiency. Above characteristics of diamond tools is determined by the state of the diamond crystal. In the diamond crystal,

the carbon atoms of the four valence electrons enter the tetrahedral bond, each carbon atom with four adjacent atoms form a covalent bond, and then form a diamond

structure, the structure is very strong binding force and direction, so that the diamond has a very high hardness. As polycrystalline diamond (PCD) of varying

orientation of the structure of fine grain diamond sintered body, although the added binding agent, the hardness and wear resistance is still lower than the single

crystal diamond. However, due to the performance of polycrystalline diamond sintered body is isotropic, so easy to split along a single cleavage plane. Polycrystalline

diamond cutting tools materials, the main performance indicators: ① polycrystalline diamond's hardness up to 8000HV, is 80 to 120 times carbide; ② thermal

conductivity of polycrystalline diamond 700W/mK, as carbide 1.5 ~ 9 times or higher than PCBN and copper, so rapid heat transfer polycrystalline diamond tools; ③ the

coefficient of friction of polycrystalline diamond is typically only 0.1 to 0.3 (the friction coefficient of carbide 0.4 to 1), the polycrystalline diamond tools can

significantly reduce the cutting force; ④ polycrystalline diamond thermal expansion coefficient of only 0.9 × 10 -6 ~ 1.18 × 10 -6, equivalent to only carbide 1/5,

so the thermal deformation of polycrystalline diamond tools, high precision ; ⑤ polycrystalline diamond tools and non-ferrous metals and non-metallic materials, the

affinity between the small chip in the process is not easy to bond formed on the tip BUE.