A convenient coating process was developed to prepare zirconia-coated zirconium diboride (ZrB₂@ZrO₂) powder by in-situ passivation reaction in the mixed hydrothermal solutions of sodium hydroxide (NaOH) and hydrogen peroxide (H₂O₂). Amounts of techniques consisted of field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) were used to study the effects of coating parameters (NaOH concentration, H₂O₂ concentration, reaction temperature and reaction time) on the microstructure and composition. The results show that the coated powder exhibits a flat surface similar to the raw powder. The coating has a full coverage and its content is controllable by adjusting reaction time. It has a double layered structure. The inner layer of the coating mainly derived from the in-situ passivation reaction is the mixture of tetragonal zirconia (t-ZrO₂) and amorphous zirconia (a-ZrO₂). The outer layer produced by the hydrothermal crystallization process is monoclinic zirconia (m-ZrO₂). The coated powder with 30 wt% ZrO₂ has excellent sintering property and contributes to reforming a dense coated structure of the sintered composite. Thus, its oxidation resistance is significantly improved at 1400 °C.

开发了一种方便的涂覆工艺，通过在氢氧化钠（NaOH）和过氧化氢（H ₂ O ₂）的混合水热溶液中进行原位钝化反应来制备氧化锆包覆的二硼化锆（ZrB ₂ @ZrO ₂）粉末。大量的技术包括场发射扫描电子显微镜（FE-SEM），透射电子显微镜（TEM），X射线衍射（XRD），X射线光电子能谱（XPS）来研究涂层参数的影响（ NaOH浓度，H ₂ O ₂浓度，反应温度和反应时间）。结果表明，涂​​覆的粉末表现出与原始粉末相似的平坦表面。涂层具有完整的覆盖范围，其含量可通过调节反应时间来控制。它具有双层结构。主要源自原位钝化反应的涂层内层是四方氧化锆（t-ZrO ₂）和无定形氧化锆（a-ZrO ₂）的混合物。由水热结晶过程产生的外层是单斜晶氧化锆（m-ZrO ₂）。具有30 wt％ZrO ₂的涂层粉末具有优异的烧结性能，并有助于重整烧结复合材料的致密涂层结构。因此，在1400℃下其抗氧化性显着提高。