低发射率SiO_2/Al_2O_3纳米复合粉体的制备和红外隐身性能

Preparation and infrared stealth properties of SiO_2/Al_2O_3 nanocomposite powders with low emissivity

采用溶胶-凝胶法制备非晶态和结晶态两种相结构的SiO2/Al2 O3纳米复合粉体,通过X射线衍射、透射电子显微镜等手段对纳米复合粉体结构和形貌进行表征,并利用傅里叶变换红外光谱仪研究纳米复合粉体的红外隐身性能.结果表明：两种相结构的SiO2/Al2 O3纳米复合粉体均呈不规则颗粒状,其中结晶态SiO2/Al2 O3纳米复合粉体的平均晶粒尺寸约为18 nm；结晶态SiO2/Al2 O3纳米复合粉体在2.5~25μm波长范围内的红外发射率均低于非晶态复合粉体,3~5μm内发射率平均值为45.65%,8~14μm内发射率平均值为46.19%,是一种低发射率的红外隐身复合纳米材料.

Crystalline and amorphous SiO2/Al2 O3 nanocomposite powders were prepared by a sol-gel method. The structure and morphology of the nanocomposite powders were characterized by X-ray diffraction and transmission electron microscopy, while the in-frared stealth property was detected by Fourier transform infrared spectroscopy spectrometry. The results show that both the nanocom-posite powders have irregular shapes, in which the average grain size of the crystalline one is about 18 nm. The crystalline nanocom-posite powder is a kind of composite nanomaterial with low infrared emissivity, and its average emissivity is 45. 65% in 3-5μm and 46. 19% in 8-14μm, which are lower than those of the amorphous one in 2. 5-25μm.