| 摘要 |
<p>A vanadium carbide material is prepared by compacting finely divided V2O3 with carbon which is at least the stoichiometric amount to form V2C but not more than 110% of this amount, and heating the compact material under conditions below atmospheric pressure to cause reaction between the V2O3 and the C and completing the reaction at a temperature of 1200 DEG C. to 1400 DEG C. and a pressure of 300 microns of Hg or less. If desired the reaction product may be contacted with nitrogen gas before it cools below 1000 DEG C., the nitrogen being in an amount sufficient to convert the V2C in the reaction product to V2CN. In modifications of the above process, metallic iron or iron oxide may be added to the V2O3/C mixture, in the latter case sufficient C being used to reduce the Fe2O3 to iron. Both of the products of these reactions may be nitrided as above. A preferred material consists of vanadium, carbon, and 2-10% iron, the material being at least 80% in the form of combined vanadium and carbon and containing less than 2% oxygen, the predominant proportion of combined vanadium being in the form of V2C, the atomic ratio of V:C being in the range 1.49 to 2.42. In the nitrided form, the ratio V:C:N is 1.49 to 2.42:1:0.35 to 1.20.</p> |
