Diamond coated tool applications

- 6/8/2018 -  1. The difference between CVD diamond coating and amorphous diamond coating
Amorphous diamond (also known as diamond-like carbon-implant) coatings are carbon films deposited using the PVD process. It not only has a local diamond SP3 bond, but also has a local carbon SP2 bond; its film hardness is very high, but it is lower than that of the diamond film; its thickness is also thinner than our usual stacked diamond film. When machining graphite, the lifetime of amorphous diamond-coated tools is 2-3 times that of uncoated carbide tools. In contrast, CVD diamond is a pure diamond coating deposited by CVD. The tool life when machining graphite is 12-20 times that of cemented carbide tools, which can increase the number of tool changes and improve the reliability and precision of processing. Disagreement.

2. Can't use diamond tools to process hardened steel
Diamond consists of carbon atoms. When some data is heated, carbon atoms are drawn from the diamond and form carbides in the workpiece. Iron is one of such materials. When processing diamond data with a diamond cutter, the heat of frictional attack causes the carbon atoms in the diamond to disperse into the iron, which constitutes a delayed effect of the diamond coating due to chemical wear.

3. It is difficult to guarantee the quality of diamond-coated tools that are regrinded and/or recoated because the resulting coating on the tool surface is pure diamond. Therefore, it takes a long time for the tool to stop regrind with a diamond grinding wheel. In addition, the tool used to grow the diamond. The preparation process will change the chemical properties of the tool's appearance. Because the coating requires a very accurate control of this chemical property stop, the tool re-coating effect is difficult to lose.

4. The peeling of the diamond coating can prevent the peeling of the coating being a serious effect of the diamond coated tool, and it is also a rare effect (especially when processing carbon fiber and the like), which will result in unpredictable tool life. In the early 1990s, the interface chemistry was identified as an important factor affecting the diamond coating adhesion.

After selecting the good compatibility of the cemented carbide chemical properties, proper pre-treatment technology and reasonable stacking reaction conditions, it is possible to aggravate or eliminate the spalling of the diamond coating and resolutely complete the bumpy wear pattern. Looking at the normal wear of the diamond-coated tool under the microscope, it was found that the diamond self-absorbed until it reached the cemented carbide substrate without chipping or flaking.

5. The life of diamond-coated tools is not the opposite
As with any other tool, the life of a diamond-coated tool is not the opposite, depending on the material being cut, the feed rate and cutting speed selected, and the geometry of the workpiece. In general, diamond-coated tools for processing graphite are 10-20 times longer than uncoated carbide tools, and in some cases can be even longer. In this way, a tool can be used to perform almost any processing duty without the need for tool change due to tool wear, preventing processing infixes and recalibration, thus enabling unattended processing. In the processing of composite data, it is also possible to achieve long tool life.

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