3 D-Cf/SiC复合材料抗高温氧化涂层结构设计与自愈合机理

摘要

为了提高3D-Cf/SiC 复合材料耐高温氧化性能，采用CVD和粉末烧结技术相结合依次在其表面制成 CVD-SiC 粘接层-自愈合功能层-CVD-SiC 耐冲蚀层等抗高温氧化涂层。运用 TG、SEM 和 TEM等手段研究了自愈合机理。结果表明，抗高温氧化涂层自愈合机理主要是 B4 C 和 MoSi2等氧化增重形成在高温下可流动的玻璃相，玻璃相充填材料裂纹和空隙有效地阻碍氧气渗透。因而3D-Cf/SiC复合材料具有较好的耐高温氧化性能。%In order to increase anti-high temperature oxidation properties of 3D-Cf/SiC composites,oxidation re-sistant coatings,including a chemical vapor deposition (CVD)SiC bonding layer,a self-sealing active layer and a CVD-SiC erosion resistant layer,were prepared on carbon fiber reinforced silicon carbide (3D-Cf/SiC)com-posites by CVD and powder sintering technology.TG,SEM and TEM were used to research self-sealing mecha-nism of the coating.The results show that the self-healing mechanism of the coating was mainly that flowing glass phases oxidized of B4 C and MoSi2 fill in material cracks and pores,and block off the passage of oxygen at high temperature.So 3D-Cf/SiC composites have good high temperature oxidation resistance properties.