Manufacture of powders of technical titanium, zirconium, chromium, and tungsten borides by the boron carbide method

Conclusions

• 1. A study was made of the preparation of commercial-purity TiB₂, ZrB₂, CrB₂, and W₂B₅ powders by the boron carbide method under industrial conditions. It was found that, for titanium and zirconium diborides, the best chemical compositions are obtained when charge reduction is performed for 60 min at 1900°C in a graphite-rod electric resistance furnace provided with a hydrogen atmosphere; for chromium diboride and tungsten boride, the reduction should be performed, also for 60 min, at 1800°C.

• 2. It is shown that commercial-purity TiB₂, ZrB₂, CrB₂, and W₂B₅ can be produced not only in a hydrogen atmosphere but also in converted gas and even without a special atmosphere; dispensing with the use of a hydrogen atmosphere has virtually no effect upon the optimum process times and temperatures.