摘要
本文研究了用化学气相渗工艺的均热法制备炭纤维增强碳化硅(C/SiC)复合材料,其中有部分材料在沉积碳化硅之前先沉积少量热解碳,以作为界面层.对有界面层和无界面层的材料进行了拉伸试验.用金相显微镜和扫描电镜观察了材料微观结构及断口形貌.结果表明,C/SiC材料力学性能主要取决于纤维与基体的界面.有热解碳界面层的C/SiC材料,在拉伸断裂时出现大范围脱粘,断口类似毛刷,材料强度大,断裂功也大.有很大的形变性;无界面层的材料表现为脆性平面断口,裂纹直接穿过纤维与基体向前扩展,材料强度小,断裂功也小.
The fabrication of C/SiC composites by isothermal method using Chemical Vapor Infiltration (GVI) processes has been studied in this paper. Bits of pyrolytic carbon which behaves as interface layer has been deposited on part of the carbon cloth lamihatcs before the deposition of silicon carbide. Tensile tests of the composites which have (have no) interface layer have been conducted. The mierostructure and the fracture surface of the composites have been observed by metalloscope and SEM. The results show that the interface layer between the fiber and the mer is one of the most important factors which influnce the mechanical properties of the C/SiC composites C/SiC composiles with pyrolytic carbon interface layer present higher values of tensile strength and fracture work brush like fiber pull - out and large scale decohesion between the fiber and the mer can be found on the fracture surface. In contrast composites which have no pyrolytic carbon interface layer have lower tensile strength and fracture work. The fracture surface is plane-like since the crack propagates directly throngh the fiber and the mer.
出处
《炭素技术》
CAS
CSCD
1995年第2期6-10,共5页
Carbon Techniques
