| 摘要 |
In order to eliminate the oxygen sensitivity of chromium carbide and vanadium carbide particles, vanadium carbide and chromium carbide particles are formed by carburizing a precursor compound at a elevated reaction temperature of about 950 degree C. Initially, the precursor compound is heated in an inert nitrogen-containing gas to the reaction temperature. Once the reaction temperature is achieved, hydrogen and a carbon- containing gas such as methane or ethylene are used to conduct the carbonization. After the carbonization has been completed, the carbonizing gas is then replaced with an inert nitrogen-containing gas and the product allowed to cool down. The carbonization cycle is adjusted so that the oxygen level is kept to less than 0.35 percent. While the nitrogen level is kept at about 2 percent. Powders produced from this process show minimal or no oxygen pickup when exposed to ambient air.
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