三维碳化硅/碳化硅陶瓷基编织体复合材料

摘要

Three dimensional textile SiC/SiC composites were fabricated by chemical vapor infil-tration,and their mechanical properties and microstructure were investigated.The density of the composites was 2.5g.cm-3 after the preform was infiltrated for 30 hours.The present composite materials exhibited excellent mechanical properties and metal-like failure behavior.The flexural strength and displacement were 860MPa and 1.2mm,respectively. Fracture toughness and work of fracture were 41.5MPa.m1/2 and 28.1kJ.m-2,respectively. The dynamic toughness was determined by using Charpy impact method and its value was 36.0kJ.m-2.%采用化学气相浸渗法(CVI)，制备出三维Hi-Nicalon SiC/SiC陶瓷基编织体复合材料.经30h CVI致密化处理后，复合材料的密度达到2.5g.cm-3.所研制的三维SiC/SiC复合材料不仅具有较高的强度，而且表现出优异的韧性和类似金属材料非灾难性的断裂特征.复合材料的主要力学性能指标为：弯曲强度860MPa，断裂位移1.2mm，断裂韧性41.5MPa.m1/2，断裂功28.1kJ.m-2，冲击韧性36.0kJ.m-2.