Chemistry of inorganic compounds – Carbon or compound thereof – Elemental carbon
Patent
1993-07-22
1996-01-09
Lewis, Michael
Chemistry of inorganic compounds
Carbon or compound thereof
Elemental carbon
264 84, 117929, C01B 3106
Patent
active
054826950
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates in general to production of superhard materials, and more specifically it concerns a carbon composition and a process for production thereof.
BACKGROUND ART
A vigorous development of nanotechnology in the recent period contributed to the creation of a new class of ultradisperse materials produced by high-energy processes.
One prior-art process is in current use for producing a carbon composition for subsequent isolation of diamonds therefrom by detonation of a carbon-containing explosive featuring a negative oxygen balance, in a neutral-gas cooling medium (cf. Nature, v. 333, 1988, June, "Diamonds in detonation soot" by N. Roy Greiner et al, pp. 440-443.
The resultant carbon composition contains diamond and graphite, both having a particle size of from 40 to 60 .ANG.. The diamond modification is isolated from the composition by virtue of oxidation of the graphite modification.
However, it is due to a little difference in size between the diamond and graphite modifications that such a composition cannot be used for superfinishing the surface of superhard materials owing to its being devoid of damping properties.
Known in the art is a process for producing a carbon composition containing up to 50 wt. % of the diamond phase having a particle size up to 1 .mu.m, by detonation of a mixture of a carbon-containing explosive featuring a negative oxygen balance, graphite, and soot in a neutral-gas cooling medium (PCT/SU 82/00458).
The effect of a detonation wave provides for conditions of a thermodynamic stability of the diamond phase, whereby part of the graphite phase turns into the diamond modification which is then extracted from the resultant carbon composition, containing the diamond phase and the residual graphite. The thus-produced diamond modification can be used as polishing powders.
However, due to its low dispersity the carbon composition produced according to the process discussed above, features high abrasiveness of a nontribomechanical nature when applied for surface finish, which results in formation of relief and disturbed layers. That is why said composition cannot be used for superfinishing the surface of hard materials nor can it be employed as an antifriction additive.
DISCLOSURE OF THE INVENTION
The present invention has for its principal object to provide a carbon composition by selecting a proper ratio between the diamond and graphite modifications thereof featuring high dispersity, which composition is capable of providing a tribomechanical nature of its effect when applied for machining hard surfaces and has high damping properties, as well as to develop a process for producing such a carbon composition due to selecting an appropriate formulation of a cooling medium which ensures high dispersity and the required ratio between the carbon components of the proposed composition.
The foregoing object is accomplished due to the fact that in a carbon composition, containing diamonds and graphite, according to the invention, the diamond particles are 40-120 .ANG. in size, while the graphite particles, 200-1000 .ANG., the ratio between the components being as follows (wt. %):
______________________________________ diamond 18-38
graphite to make up 100.
______________________________________
The herein-proposed carbon composition consists of ultradisperse components possessing tribomechanical nature of interaction with the surface being machined, which provides for removal of the material being polished without any mechanical disturbances of the surface involved. The carbon composition, according to the invention, has elastic properties due to its containing two carbon modifications, a diamond and a graphite, which are characterized by different grain microhardness, whereby abrasive treatment of hard materials can be performed to attain high quality of surface finish. The principal abrasive effect is exerted by the diamond modification, whereas the graphite modification serves as a damping layer preventing high impact load on the diamond modific
REFERENCES:
patent: 3238019 (1966-03-01), De Carli
patent: 4483836 (1984-11-01), Adadurov et al.
patent: 4500672 (1985-02-01), Suzuki et al.
patent: 4552742 (1985-11-01), Mayer
patent: 5087435 (1992-02-01), Potter et al.
International Search Report PCT/SU91/00135 w/English translation.
Guschin Viktor A.
Lyamkin Alexei I.
Staver Anatoly M.
Zakharov Alexandr A.
Hendrickson Stuart L.
Lewis Michael
Staver Anatoly Mikhailovich
LandOfFree
Carbon composition production process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Carbon composition production process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carbon composition production process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1301185