Silicon Carbide Whiskers Reinforced Alumina Coatings on SiC-SiC Composites

这个小型企业创新研究第一阶段项目描述了一种独特的方法，可以在SiC-SiC复合材料上生产粘附性更好的抗热震涂层。碳化硅正在评估工业热交换器应用。在热交换器应用中，SiC陶瓷在腐蚀环境中的高温使用限于约1200 ° C。进行了几次尝试以在SiC衬底上施加保护性氧化铝外层。氧化铝和SiC之间的热失配使得不可能在SiC衬底上获得粘附的氧化铝涂层。提供强粘附晶须生长离开基底，氧化铝涂层的后续沉积将导致形成粘附的、增加的韧性和抗热震的氧化铝涂层。SiC增强氧化铝涂层的热机械性能将取决于晶须以及氧化铝涂层的性能。将进行晶须性能和涂层微观结构的定制，以在SiC衬底上获得粘附的氧化铝涂层，能够经受高达1400 ℃的热循环。

This Small Business Innovation Research Phase I project describes a unique way to produce adherent, improved thermal shock resistance coatings on SiC-SiC composites. Silicon carbide is being evaluated for industrial heat exchanger applications. High temperature use of SiC ceramics in corrosion environments is limited to about 1200ÝC in heat exchanger applications. Several attempts were made to apply a protective alumina external layer over the SiC substrate. Thermal mismatch between alunina and SiC made it impossible to obtain adherent alumina coatings on SiC substrate. Providing strong-adherent whiskers are growing-off the substrate, the subsequent deposition of alumina coatings will result in a formation of adherent, increased toughness, and thermal shock resistant alumina coating. Thermomechanical properties of the SiC-reinforced alumina coating will be dependent on the whiskers as well as alumina coating properties. Tailoring of whiskers properties and coating microstructure will be performed in order to obtain adherent alumina coatings on SiC substrates, capable of surviving thermal cycling up to 1400ÝC.