碳/碳-碳化硅复合材料制备及性能研究

Synthesis and Ablation Resistance of C/C-SiC Composite Material: An Experimental Study

为了提高航母舰载机燃气导流板的性能,对碳/碳-碳化硅(C/C-SiC)复合材料开展制备和性能研究。采用轴棒法编制预制体,采用化学气相渗透工艺制备试件。将试件在舰载机的尾流中做模拟起飞工况的飞行试验。采用电子天平和千分尺测量试件的烧蚀率,采用能谱分析测量燃烧产物的成份,采用扫描电镜观察试件烧蚀后的微观形貌的变化,并对试件的烧蚀机理进行分析。结果表明:试件的质量烧蚀率为0.0405 g/s,线烧蚀率为0.0488 mm/s;试件中SiC在高温下反应生成的SiO2在碳纤维的周围沉积,形成了包鞘结构,有效地阻滞了氧化反应向内部继续传递,从而降低了试件的烧蚀率,材料总体表现出优异的抗烧蚀性能。

The high density C/C-SiC,an advanced composite material of carrier-based aircraft gas guide plate,was fabricated in two steps,first,a rigid C-fiber rod,strengthened with an optimized structure of knitted C-fiber,was fabricated in axial rod method and then,the SiC thin films were coated on surfaces of the prefabricated highly porous substrate by chemical vapor deposition.The influence of the simulated aircraft gas on the microstruc tures,ablation-rate and ablated slag of C/C-SiC sample was investigated with scanning electron microscopy,energy dispersive spectroscopy and electronic balance.The results show that the newly-developed C/C-SiC composite material does an excellent job as the carrier-based aircraft gas guide-plate.For example,the linear(mass)ablation?rate was about 0.0488 mm/s(0.0405 g/s),and the compact SiO2 coatings,formed in the ablation on the surfaces of SiC-coated C-fibers with strong ablation-resistance in the ablated layers,act as a good oxidation barrier.