AIST tohoku has developed a mirror-polished diamond slider with a
low friction coefficient close to air-floating conditions. A coating
technique has been established for Chemical Vapor-Deposited (CVD)
diamond film onto machinable titanium silicon carbide. This technology
affords a much improved degree of freedom in selecting the shape of
the substrate.
The superior sliding performance is attributed to the mixed lubricant
effect resulting from a combination of the solid diamond lubricant
and the fluid lubricant brought about by the intervening air. It becomes
also possible to use a machinable titanium silicon carbide as the
substrate for diamond deposition. Until the present, fabrication of
CVD diamond has only been possible on flat substrate surfaces or for
small cutting tools. With the new technology, however, it will be
possible to use this process for coating any shape of sliding surfaces.
In the past, the suitable materials as substrates for CVD diamond
were limited to brittle silicon or very hard silicon carbide and silicon
nitride, or tungsten carbide that are heavy and difficult to machine.
The newly developed diamond sliding surface essentially presupposes
the use of a diamond-to-diamond combination. At low contact pressures,
however, it is also possible for the diamond surface to mate with
a metal surface, since the diamond film will provide a smooth air-floating
like sliding performance also with machined surfaces such as stainless
steel.
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| CVD
diamond slider put on a stainless steel guide. |
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| Relational Information |
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AIST Today Vol. 3, No. 1 (2003) 23
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No.8
Spring 2003
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