纳米结构莫来石粉体喂料的制备与表征

Preparation and Characterization of Nano-Structured Mullite Feedstock

环境障涂层(Environmental barrier coating,EBC)是设立在服役环境和发动机材料之间阻止或减小环境对发动机侵蚀的表面防护层。莫来石具有良好的耐高温性、化学兼容性、抗氧化性和导热性,被视为环境障涂层的重要材料。对纳米结构莫来石粉体喂料的制备工艺进行了研究,目的是制备出球形度好、表面光滑、流动性好、致密度高的纳米结构粉体喂料。以纳米Al_(2)O_(3)、SiO_(2)粉体为原材料,采用湿法球磨、喷雾干燥、固相烧结的方法制备了用于环境障涂层的纳米结构莫来石粉体喂料。借助X射线衍射仪和扫描电镜研究了粉体喂料在不同热处理温度下的组织与形貌。结果显示,1300℃+150 min的固相烧结的球形度与喷雾干燥所得的球形度保持一致,表面也较为光滑,缺陷较少,莫来石粉体喂料的粒径在60μm左右,晶粒为纳米结构。

Environmental barrier coating(EBC)is a surface protection layer established between the service environment and the engine material to prevent or reduce the environmental erosion of the engine.Mullite is regarded as an important material for environmental barrier coating due to its good high temperature resistance,chemical compatibility,oxidation resistance and thermal conductivity.The preparation process of nanostructured mullite feedstock was studied,and the purpose was to prepare nanostructured feedstock with good sphericity,smooth surface,good fluidity and high density.This paper uses nano Al_(2)O_(3) and nano SiO_(2) as raw materials,and uses spray drying and solid phase sintering methods to prepare nanostructured mullite feedstock.The microstructure and morphology of feedstock at different heat treatment temperatures were studied by means of X-ray diffractometer and scanning electron microscopy.The experimental results show that the sphericity of solid-phase sintering at 1300℃+150 min is consistent with the sphericity of the feedstock obtained by spray drying,and the surface is relatively smooth,with fewer defects,the particle size of the feedstock is about 60μm,and the grain is nano structure.