Development of Control Method of Interface of h-BN Composites by Fracto-emission Analysis

本研究的目的是利用断口发射分析方法，通过控制界面，研制出比C/C复合材料具有更好的抗氧化性、高强度和高韧性的高性能长纤维增强陶瓷基复合材料。本研究取得的主要成果如下：1.设计并研制了主要设备--压裂释放量分析系统。这台设备有探测电子和光子的探测器。当热压温度为1800ﾟ时，h-BN：60wt%，Si3N4：28wt%，SiO_2：12wt%，Y203：3wt%是制备密度最高的h-BN体系的最佳工艺条件。制备了碳纤维增强h-BN基复合材料。在室温至1,600ﾟC的条件下，测试了该复合材料的强度，其中1,600ﾟC的强度是室温强度的两倍，即350 MPa。为了描述这一现象，提出了一种基于界面特性的模型。尝试了制备h-BN基复合材料的最佳工艺条件，并成功地显著提高了材料的室温强度。

The aim of this research is to develop a high performance long fiber reinforced ceramic matrix composites which has excellent oxidation resistance, high strength and high toughness than C/C composites by controlling interfaces using fracto-emission analysis method. The main results obtained in this research are as follows ;1. Main equipment, the fracto-emission analysis system, was designed and produced. This equipment has probes for detecting electrons and photons.2. The optimum condition for making the most dense h-BN matrix system was found as h-BN : 60wt%, Si3N4 : 28wt%, SiO2 : 12wt% and Y203 : 3wt% under the hotpressing temperature 1,800ﾟC.3. Carbon fiber reinforced h-BN matrix composites were fabricated. The strength of this new composite was measured under the conditions from the room temperature to 1,600ﾟC.The strength at 1,600ﾟC was double the value of room temperature, namely, 350MPa. A model based on the special natures of interfaces was presented for describing this phenomena.4. The optimum condition for fabricating the h-BN matrix composites was tried and succeeded in improving the room temperature strength significantly.