| 摘要 |
<PICT:1077469/C1/1> <PICT:1077469/C1/2> Diamond is produced from another form of carbon by subjecting a body of said carbon to an explosively generated shockwave which impinges on substantially the whole of at least one face of the carbon and whose amplitude is so correlated with the density of the carbon that it develops therein a maximum temperature below 2000 DEG C. and a pressure from 100 to 700 kilobars sufficient to convert at least part of the carbon into diamond. The carbon body may have a planar face which is subjected to the shock wave simultaneously over the whole area of the face and the wave may be reflected back into the carbon from a planar face opposite that initially subjected to the wave. The explosive used to generate the shock may be contiguous with the carbon or separated by a gap or mechanically weak separator, e.g. as for a flying plate. The carbon may be placed in relation to a body of liquid so that after it has been subjected to the shock wave the residue of carbon is caught in the liquid from which it is easily recovered. One type of apparatus, Fig. 2, suitable for use in the process of the invention comprises a plane wave generator 10 which detonates a charge of standard explosive 12 which is in contact with more high explosive 14 in a shell 20, e.g. of glass, surrounding the sample of graphite 16 which may be spherical, contained in a copper shell 18 which are placed in the tank 22 filled with sand 24. In another embodiment illustrated by Fig. 4, a plane wave explosive generator 28 detonates a high explosive 29 which rests on a "flying plate" 30 made of metal supported by plastic stand-offs 32A, 32B, which are supported upon a metal ring 34. Carbon 36 is placed in an aperture in 34 supported on a metal plug 38, on detonation the flying plate shears the edges of the plate from the central position and impact from the plate applies pressure to the carbon. Examples of suitable carbonaceous materials include graphite, artificial graphites and graphitic carbons, petroleum coke, coal coke and lamp-black. missing page 30
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