1、 中文中文 40404040 字字 附录 外语文献原文 英文原文 Oxidation behavior and mechanical properties of C/SiC composites with Si-MoSi2 oxidation protection coating YONGDONG XU, LAIFEI CHENG, LITONG ZHANG, HONGFENG YING, WANCHENG ZHOU State Key Laboratory of Solidifi cation Processing, Northwestern Polytechnical University
2、,Xian, Shaanxi 710072, Peoples Republic of China A new kind of oxidation protection coating of Si-MoSi2 was developed for three dimensional carbon fi ber reinforced silicon carbide composites which could be serviced upto 1550 . The overall oxidation behavior could be divided into three stages: (i)50
3、0 T 800 , the oxidation mechanism was considered to be controlled by the chemical reaction between carbon and oxygen; (ii) 800 T 1100 , the oxidation of SiC became signifi cant and was controlled by oxygen diffusion through the SiC layer. Microstructural analysis revealed that the oxidation protecti
4、on coating had a three-layer structure: the out layer is oxidation layer of silica glass, the media layer is SiCMoSi2 layer, and the inside layer is SiC layer. The coated C/SiC composites exhibited excellent oxidation resistance and thermal shock resistance. After the composites annealed at 1550 for
5、 50 h in air and 1550100 thermal shock for 50 times, the fl exural strength was maintained by 85% and 80% respectively. The relationship between oxidation weight change and fl exural strength revealed the criteria for protection coating was that the maximum point of oxidation weight gain was the fai
6、lure starting point for oxidation protection coating. 1. Introduction Carbon fi ber reinforced silicon carbide composite(C/SiC) is a kind of promising thermal structure composites for use in applications requiring high strength,low density, and high fracture toughness at elevated temperatures in aero-engines and aerospace1. However, a severe problem is that the carbon fi ber and in-terfacial layer of the composite are easy to be attacked by oxygen in air at the temperatures as lo
