Preparations of Molybdenum/Tungsten Borides by Boriding Molybdenum/Tungsten Powder with Boron Nitride.

Molybdenum (or tungsten) borides are typical high-hardness and wear-resistant materials. In this paper, a novel method to prepare Mo (or W) borides was proposed by boriding metal Mo (or W) powder with h-BN at 1723 K. The experimental results showed that single-phase Mo₂B, MoB and W₂B could be easily obtained in both Ar atmosphere and vacuum. However, under the same temperature, pure WB could be prepared only in vacuum. At the same time, the elemental analysis showed that the residual O and N contents in the products were sufficiently low. Besides, the inheritance connection of granularity between boride products and metal powders was found by using Mo (or W) powder with different particle sizes as raw materials. [ABSTRACT FROM AUTHOR]