Types of diamond drawing dies
: what are the differences between CVD diamond and single crystal diamond, PCD diamond and PDC diamond?
Synthetic large single crystal diamond, PCD and PDC are synthesized under high temperature and pressure, while CVD diamond is prepared under low pressure. The mixture of carbon-containing gas and oxygen is stimulated to decompose at high temperatures and pressures below standard atmospheric pressure to form active diamond carbon atoms.
Polycrystalline diamond (or single or quasi-single crystals of diamond deposited under controlled deposition conditions) is formed on the substrate. Because CVD diamond does not contain any metal catalysts, its thermal stability is close to that of natural diamond. Like Synthetic Polycrystalline Diamond at high temperature and high pressure, CVD diamond grains are disorderly arranged without brittle cleavage surface, so they are isotropic. The application of thermal properties of CVD diamond due to its various properties. An important property of CVD diamond is its high thermal conductivity. At room temperature, the thermal conductivity of diamond is five times that of copper. At the same time, it is also an excellent insulating material. Therefore, diamond film can be used to produce heat sink materials for high power optoelectronic components.
Application of CVD diamond optical properties. Diamond has a high spectral transitivity in a long wavelength range from ultraviolet to far infrared. The excellent mechanical and thermal properties of diamond make diamond film an excellent optical window material for use in harsh environments. The high hardness and wear resistance of diamond make diamond film an excellent tool material. As tool materials, diamond films can be used in two different ways. The first is to peel off the deposited diamond film and then cut, grind and weld it to the end of the tool. Because the brazing strength is much lower than the bonding strength between the diamond layer and the cemented carbide of PDC material. When it is used in intermittent cutting, the interface connection becomes very fragile. If the brazing problem of CVD diamond can be solved, CVD diamond tool materials will be able to compete with PCD materials in the whole field of mechanical processing. Compared with PCD, this material has the advantages of good thermal stability and long tool life. The disadvantage is that the cohesive strength between grains is low, and the material exhibits greater internal stress and brittleness. In addition, the lack of conductivity of CVD diamond hinders the application of EDM and polishing technology. This technology has been widely used in the diamond tool processing industry, especially in the grinding and heavy grinding of wood tools. The second way is to deposit diamond film directly on the tool surface. The film thickness is thinner and the cost is lower. This method also has shortcomings: the adhesion of the deposited film to the substrate material is not easy to improve.