The user before the selection and use of diamond coated tools, must understand the diamond coating tools the following common sense:
(1) the difference between CVD diamond coating with amorphous diamond coating
Amorphous diamond (also known as diamond-like carbon coatings -- ") is a kind of carbon films deposited by PVD process. SP3 it has a part of diamond, but also has a part of the SP2 bond carbon; the film hardness is very high, but lower than the hardness of diamond film; the thickness of the diamond film deposition than we usually thinner. The processing graphite, amorphous diamond coated tool service life is 2-3 times of uncoated carbide tool. In contrast, CVD diamond is pure diamond coatings deposited by CVD process, the tool life and processing Shi Moshi 12-20 times that of carbide cutting tools, which can reduce the number of changing knife, improve the reliability and precision of consistency processing.
(2) not with diamond tool in Machining Hardened Steel
Diamond carbon atoms by. Some of the material is heated, the diamond suck carbon atoms and the formation of carbides in the workpiece. Iron is one of such material. With diamond tool in machining iron materials, friction heat will make the diamond in the diffusion of carbon atoms into the iron, resulting in early failure because of diamond coating and chemical wear.
(3) the regrinding and (or) diamond film coated tool quality is difficult to guarantee the coating coating tool surface is pure diamond grinding, so take a long time to use the diamond grinding wheel cutter. In addition, the tool used for diamond growth. Preparation process will change the chemical properties of tool surface, because the coating requires very precise control of the chemical properties, so the tool to coating effect is difficult to be guaranteed.
(4) the life of diamond coated tools vary
As with any other tool, diamond coated tool life also each are not identical, mainly depends on the feed rate and cutting speed, cutting material is selected, and the geometry of the workpiece. In general, the diamond coated tool machining graphite. The service life is 10-20 times of uncoated carbide tool, and in some cases may even longer. In this way, you can use a tool to perform almost any task, without tool change due to the tool wear, avoid the processing interrupt and recalibration, realizes unattended processing. In the process of composite, it is entirely possible to obtain longer tool life.
According to reports, in the processing of high density glass fiber, carbon fiber and Gl0-FR4 hard machining of composite materials, diamond coated tool life can be up to 70 times the uncoated carbide tool.
(5) diamond coating spalling can prevent coating peeling is a serious problem in diamond film coated tool, is also a common problem (especially in processing like carbon fibre material), will lead to unpredictable tool life. Go up century 90 time later period, interfacial properties are determined to be the important factors to influence the performance of the diamond coating adhesion. Through the selection of hard alloy chemical properties, good compatibility with pretreatment technology appropriate and reasonable deposition reaction conditions, it may reduce or eliminate the diamond coating spalling, stably realize smooth wear pattern. Observation of diamond coated tool, normal wear under the microscope can be found, the diamond stable wear until the cemented carbide substrate, while no chipping or peeling.