CVD diamond coated with amorphous diamond coating difference  Amorphous diamond

coatings are deposited using a PVD process carbon. It has a key part of the diamond SP3, SP2 also has some carbon bond; their film hardness is high, but lower than the hardness of diamond film; thickness than we usually deposited diamond film to be thinner. Machining graphite, amorphous diamond coated tool life is uncoated carbide tools 2-3 times. In contrast, CVD diamond is deposited using CVD process pure diamond coating, machining  carbide tipped saw blade graphite carbide cutting tool life is 12-20 times, thereby reducing the number of tool changes to improve the reliability and accuracy of processing consistency. 
(2) can not be used diamond tool machining hardened steel 
Diamond from carbon atoms. Certain materials when heated, sucked from the carbon atoms in diamond and carbide is formed in the workpiece. Iron is one such material. Cutting tools with diamond iron group material, the friction generated heat causes diffusion of carbon atoms in the diamond into the iron, the resulting diamond coating due to chemical wear and premature failure. 
(3) re-grinding and (or) heavy coating  construction tools  of diamond coated tools is difficult to guarantee the quality of the coating formed on the surface as the tool for the pure diamond, so the tool with a diamond wheel for re-grinding takes a very long time. In addition, the growth of the diamond tool used. Preparation of the tool will change the chemical properties of the surface, since the coating of this chemical properties requires very precise control, so the effect of the tool recoating difficult to be guaranteed. 
(4) diamond coated tool life varies 
Like any other tool, diamond coated tool life varies, depending on the material to be cut, the choice of feed rate and cutting speed, and the geometry of the workpiece and so on. Generally, diamond-coated graphite machining tool life is uncoated carbide tools 10-20 times, in some cases, may even be longer. This way, you can use a tool to complete almost any processing tasks without tool change due to tool wear and to avoid disruption and recalibration process, making it possible to achieve unattended machining. The processing of the composite material, is entirely possible to obtain a longer tool life. 
According to reports, in the processing of  cutting discs high-density glass fiber, carbon fiber and Gl0-FR4 other difficult machining composite materials, diamond-coated tool life up to uncoated carbide tool 70 times. 
(5) diamond coating spalling can prevent flaking coating of diamond-coated tools are a serious problem, but also a common problem (especially in the processing of materials like carbon fiber), will lead to unpredictable tool life. The late 1990s, interfacial chemical properties were identified as affecting the diamond coating adhesion properties of important factors. By selecting good compatibility Carbide chemical characteristics, the use of appropriate technology and reasonable pre-deposition reaction conditions, it is possible to reduce or eliminate the diamond coating spalling, stably smooth wear patterns. Observed under the microscope normal wear diamond coated tool, you can find the diamond was worn until stable carbide substrate, without chipping or peeling.