氮化硼纤维是一种新型的无机纤维。它的制备是以氧化硼纤维为前躯体,在氨气氛中加热形成部分氮化的一次氮化硼纤维,再经热处理过程转化成主要成分为氮化硼的二次氮化硼纤维。本文应用透射电镜和扫描电镜深入研究了氮化硼纤维的晶体结构、晶粒形貌与大小、结晶度、取向性以及纤维的内部缺隐与表面缺陷。首先应用透射电镜的选区电子衍射技术对几种不同工艺条件下制备的一次氮化硼纤维、二次氮化硼纤维试样与六方晶系氮化硼制品试样进行了晶体结构的对比分析。结果表明,本研究的氮化硼纤维是一种取 Boron nitride fiber is a new type of inorganic fiber. The preparation method comprises the following steps: taking boron oxide fiber as a precursor, heating to form a partially nitrided primary boron nitride fiber in an ammonia atmosphere, and then converting the secondary boron nitride fiber into a boron nitride by a heat treatment process. In this paper, the crystal structure, grain morphology and size, crystallinity and orientation of the boron nitride fiber and the internal defects and surface defects of the fiber were deeply studied by TEM and SEM. First of all, by using the transmission electron microscopy of selected area electron diffraction technology prepared under several different conditions of boron nitride fiber, boron nitride fiber samples and hexagonal boron nitride samples were crystal structure of the comparative analysis. The results show that the boron nitride fiber of this study is a kind of take