| 摘要 |
<PICT:0914322/III/1> In the catalytic conversion of carbon to diamond under high pressure and temperature, layers of carbon and a metallic catalyst are arranged alternately. The carbon may be in the form of graphite. The pressure may be 50,000-90,000 atmos., the temperature 1300 DEG -1800 DEG C., and the time of treatment up to 90 minutes. Catalytic metals specified are chromium, manganese, tantalum, and members of Group VIII of the Periodic Table. An alloy of two or more catalyst metals, or one or more catalyst metals and one or more non-catalyst metals, may be employed. Non-catalyst metals specified are aluminium, molybdenum, copper, titanium, zirconium, boron, silicon, vanadium, and tungsten. The layers may be in the form of discs 15 and 16 (Fig. 2). Catalyst and carbon discs may be 0,02 inch and 0,10 inch respectively. The electrically heated high pressure apparatus described in Specification 830,210 may be employed (Figs. 1 and 3, not shown). |
