SiC涂层制备及辐射性能分析(英文)

Synthesis of SiC Coatings and Evaluation of Their Emissivity

模板热防护涂层是高超声速飞行器热防护系统(TPS)的重要组成部分,具有高发射率的涂层可以增强TPS系统效率。将SiC、C0_3O_4纳米粉与A1_2O_3溶胶混合球磨后,采用溶胶-凝胶法在镍基高温合金表面制备了SiC涂层。利用扫描电子显微镜观察涂层的微观形貌,测定了涂层的光谱发射率。分析了涂层发射率与厚度的关系。结果显示,涂层具有较高的发射率,厚度在20-30um范围内,发射率具有最高值。

Thermal protection coatings are one of the important parts of thermal protection system(TPS) for hypersonic vehicles.The coatings with high emissivity can enhance the thermal protection effect of TPS.SiC coatings were prepared by mixing SiC and Co_3O_4 mixture slurry into Al_2O_3 sol-gel on the nickel superalloy surface by the method of dip-coating.The microstructures of coatings were investigated by scanning electron microscope(SEM).The emissivity of SiC coatings was measured by Fourier transform infrared spectrometer.The relationship between emissivity and thickness of coatings was examined.The results show that SiC-Co_3O_4 coatings have high emissivity at full-wave band.When the thickness of coatings is 20~30 μm,SiC-Co_3O_4 coatings take on the highest emissivity.