中文摘要：

利用气体雾化方法研究了Cu-20％Co（质量分数）合金的快速凝固行为，获得了富Co相以微细球形粒子形式分布于基体的合金粉末．建立了Cu-Co雾化液滴快速凝固过程模型，模拟分析了雾化液滴凝固的动力学细节．结果表明：所建模型能很好地描述Cu—Co合金雾化液滴冷却凝固过程；液-液相变过程中组织演变是弥散相液滴形核、长大、碰撞凝并和空间迁移共同作用的结果；雾化液滴尺寸越大，冷却越慢，富Co相液滴的形核速率越低，凝固后富Co相的弥散度越差．

英文摘要：

Gas atomization experiments were carried out with Cu-20%Co alloy （mass fraction）. Powders with a fine dispersion of the Co-rich particles were obtained. A model was developed to describe the solidification process of the atomized drops. The kinetic details of the microstructure evolution in the drops were calculated. It was indicated that the numerical results had a good accordance with the experimental ones. The microstructure development during the liquid-liquid decomposition was a result of the concurrent action of the nucleation, the growth of the minority phase droplets, the collision coagulations between the droplets and the spatial separation of phases. A bigger drop achieved a lower cooling rate and a lower nucleation rate of the minority phase droplets. It exhibited, therefore, a coarse Co-rich particle microstructure.