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Preparation and Properties of Silicon Nitride Fibers by Nitridation of Polycarbosilance

Abstract

氮化硅(Si3N4)纤维作为一种重要的陶瓷纤维,具有优越的力学性能、良好的耐热冲击性、耐氧化性,同时由于Si3N4纤维具有较高的高温电阻率和良好的高温介电性能,使其成为了理想的高温透波陶瓷基复合材料的增强体,在航天及先进国防装备上具有重要的用途。由于涉及国家安全等问题,自主研发连续Si3N4纤维具有巨大的军事意义及发展前景。先驱体转化法是制备连续Si3N4纤维的主要方法,本文采用无氧电子束辐射交联的PCS纤维经热解氮化制备Si3N4纤维。 本文主要研究了热解氮化的反应机理以及热解工艺对纤维结构和性能的影响。热解氮化过程是采用NH3进行脱碳氨化,然后在N2气氛下高温热引发缩合/转氨基反应产生硅...Continuous silicon nitride (Si3N4) fibers are one of important ceramic fibers, due to their many ascendant properties such as excellent mechanical properties, thermal shock resistance, oxidation resistence. What is more, because of their high electrical resistivity at high temperature and excellent high temperature dielectric characteristics, Si3N4 fibers are regarded as one of the most sutiable r...学位:理学硕士院系专业:材料学院材料科学与工程系_高分子化学与物理学号:2072009115006

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