Synthesis of high-entropy boride powders via boro/carbothermal reduction method

In this paper, high-purity and fine (W0.2V0.2Ta0.2Nb0.2Ti0.2)B-2 (HEB) powders were obtained via a simple high-energy ball milling-assisted boro/carbothermal reduction method at 1600 degrees C. Results showed that the heating temperature and B source contents played a key role in the synthesis of purity of single-phase HEB powders. When excess 10 wt.% B4C was introduced, the single-phase HEB powders were synthesized at 1600 degrees C, and its grain size was similar to 150 nm and it showed the hexagonal crystal structure of metal diborides. EDS results showed the high compositional uniformity of W, V, Ta, Nb, Ti and B elements in HEB powders. Through discussing the thermodynamics process related to these possible chemical reactions and combining the XRD results at different temperatures, it was obtained that higher temperature and enough B source were required to stimulate the formation of high-entropy phase. This work will be a vital step for the commercialization of high-entropy boride powders.

Automated summary

In this study, high-purity and fine HEB powders were obtained using a high-energy ball milling-assisted boro/carbothermal reduction method at 1600 degrees C. The synthesis of single-phase HEB powders was found to be influenced by the heating temperature and B source contents, requiring higher temperature and enough B source for the formation of high-entropy phase. The results suggest an important step towards commercialization of high-entropy boride powders.