CVD diamond coating and the difference between the amorphous diamond coating

(1) CVD diamond coated with amorphous diamond coating difference
Amorphous diamond ( also called diamond-like carbon - Annotation ) coatings are deposited using a PVD process carbon . It has a key part of the diamond SP3 , SP2 also has some carbon bond ; their sds hammer drill bits  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 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 hardened steel with diamond tooling
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  diamond blade circular saw to chemical wear and premature failure . 
( 3 ) re-grinding and ( or ) heavy coating 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 high-density glass fiber , carbon fiber and Gl0-FR4 other difficult cutting blades  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 .