Spherical AlN powders with micrometer size have attracted great attention owing to their good fluidity and dispersity. However, the industrial preparation methods usually require high temperature and long soaking time, which lead to the high cost and limit the wide application of the products. Herein, nearly spherical AlN particles with the average size of 2.5 µm were successfully synthesized via an in-situ combustion synthesis method. The effect of N₂ pressure, NH₄Cl content, and Al particle size on the combustion reaction procedure, phase composition, and microstructure of the products was systematically investigated. The results showed that the decreased N₂ pressure, increased NH₄Cl content, and Al particle size led to the decreasing of combustion temperature and speed, which further affected the morphology of the products. As a result, low N₂ pressure (0.2 MPa), a small amount of NH₄Cl (0.5 wt%), and fine Al particles (∼2.5 µm) contributed to a moderate combustion temperature and facilitated the formation of nearly spherical AlN particles. In addition, based on the gas-releasing assisted quenching experiments and thermo-kinetic analysis, a two-step growth mechanism for the nearly spherical AlN particles was rationally proposed. The present method shows the advantages of low cost and high efficiency for preparing nearly spherical AlN particles, which can be used as raw materials for electronic substrates and fillers for packaging materials.

微米级球形AlN粉末由于其良好的流动性和分散性而备受关注。然而，工业制备方法通常需要高温和较长的浸泡时间，这导致高成本并限制了产品的广泛应用。在此，通过原位燃烧合成法成功地合成了平均粒径为2.5μm的近似球形的AlN粒子。系统地研究了N ₂压力，NH ₄ Cl含量和Al粒径对燃烧反应过程，相组成和产物微观结构的影响。结果表明，降低N ₂压力，增加NH ₄Cl含量和Al颗粒尺寸导致燃烧温度和速度的降低，这进一步影响了产物的形态。结果，较低的N ₂压力（0.2 MPa），少量的NH ₄ Cl（0.5 wt％）和细的Al颗粒（〜2.5 µm）有助于中等燃烧温度，并有助于形成接近球形的AlN颗粒。此外，基于气体释放辅助淬火实验和热动力学分析，合理地提出了近球形AlN颗粒的两步生长机理。本方法显示了制备几乎球形的AlN颗粒的低成本和高效率的优点，其可以用作电子基板的原料和包装材料的填料。