基于Ti-B_4C-C反应体系制备空心陶瓷沉珠的方法与机理研究

Preparation and mechanism of hollow ceramic microspheres based on Ti-B_4C-C reaction system

研究了一种制备空心陶瓷沉珠的方法与机理。以Ti-B4C-C为反应体系,基于传统火焰热喷涂原理和设备,熔射经团聚处理的自反应型复合粉体,使之在飞行过程中发生自蔓延高温合成反应,产生陶瓷雾化熔滴,采用温度可控的介质将其接收、冷却,使之快速凝固、结晶,从而获得中空结构、原位合成的空心陶瓷沉珠。空心陶瓷沉珠形成过程经历了反应孕育、自蔓延反应引燃、团聚粉粒爆燃和陶瓷液滴凝固结晶4个阶段。制备出的空心陶瓷沉珠由TiC0.3N0.7-TiB2-TiO2复相组成,空心陶瓷沉珠的直径为50μm左右、壁厚在10μm左右。该方法制备的空心陶瓷沉珠所需设备简单,工艺灵活,适应性强,反应原料和制造运行成本低廉。

In this paper,a method of preparation and mechanism of hollow ceramic microspheres is researched. With Ti-B4C-C as the reaction system,based on traditional principles and flame thermal spray equipment,spray self-reactive compound powders which are treated by the reunion so that could make them occur the self-propagating high-temperature synthesis reaction during the flight to produce ceramic melt drops,and then using a temperature-controlled media to receive and cool them to rapid solidification and crystallization,and thus to obtain hollow structures,in-situ synthesis of hollow ceramic microspheres. The formation of hollow ceramic microspheres experience four stages：a reaction to birth,self-propagating reaction ignition,deflagration and crystallization of reunion ceramic powder. So hollow ceramic microspheres prepared are composed of complex phase TiC0.3N0.7-TiB2-TiO2,diameter of hollow ceramic microspheres is around 50μm in and wall thickness at around 10μm. Hollow ceramic microspheres prepared by this method possess advantages of simple equipment,process flexibility,adaptability,low-cost of raw materials and manufacturing operation.