| 摘要 |
A submicrometer transition metal carbonitride is produced having the formula : MaM'bM''(1-a-b)(C(1-x)Nx)z, wherein M is Ti, Zr or Hf; M' is V , Nb or Ta; M'' is Cr, Mo or W; a ranges from 0 to 1; b ranges from 0 to 1 with the proviso that (a+b) is less than or equal to 1; x ranges from 0.02 to 0.95 and z ranges from 0.9 to 2. The transition metal carbonitride is produced by mixing (a) a transition metal oxide source of a transition metal in the above formula and (b) a carbon source such as carbon black. This mixture is heated at a rate of between 100 K/sec to 100,000,000 K/sec in a nitrogen containing non-oxidizing gas such a s nitrogen or nitrogen mixed with argon to an elevated temperature that makes carbothermal reduction of the transition metal oxide source thermodynamicall y favorable for a residence time sufficient to convert the transition metal oxide source into at least one product selected from the group consisting of : (i) a transition metal carbonitride and (ii) a transition metal carbonitride precursor. The product may be exposed to a finishing step involving heating the product to a temperature less than the elevated temperature in a finishi ng atmosphere such as nitrogen, hydrogen, inert gas or combinations thereof to form submicrometer carbonitrides of higher purity or different stoichiometry .
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