Low temperature synthesis of ZrB2 powder synergistically by borothermal and carbothermal reduction

Abstract

To achieve a ZrO2-B-C ternary solid-state reaction, a small amount of carbon was introduced into a binary system of ZrO2 and boron. Amorphous hydrous ZrO2 precursor was firstly prepared through precipitation method using zirconyl nitrate and ammonia at room temperature. Then, ZrB2 powder was successfully synthesized using the as-prepared amorphous hydrous nano-ZrO2 via borothermal and carbothermal reduction (BCTR) by amorphous boron and nanocarbon powders under flowing argon. Plate-like ZrB2 particles with a uniform distribution and ca. 1.0 μm in two-dimensions were obtained with a B/Zr molar ratio of 4, and 5 wt.% (total weight of dry hydrous ZrO2 and boron) nanocarbon at 1550 °C for 2 h.