【摘要】 目的提高Co-WC太阳能选择性吸收涂层的吸收性能。方法采用溶胶-凝胶法在超音速火焰喷涂（HVOF）制备的Co-WC涂层上涂覆Co₃O₄-CoAl₂O₄薄膜。在大气环境下,对样品进行梯度温度热处理,通过XRD表征在不同热处理温度下涂层的组成成分;利用FE-SEM和表面粗糙度仪观察涂层表面微观结构和测量涂层表面粗糙度;通过天平称量涂层质量变化来评价Co₃O₄-CoAl₂O₄涂层在不同温度下的服役性能;借助EDS分析Co₃O₄-CoAl₂O₄涂层的元素分布情况;使用UV-Vis-NIR分光光度计测试涂层的吸收性能。结果经过Co₃O₄-CoAl₂O₄薄膜改善后,Co-WC涂层的吸收性能提高。其中在650℃热处理温度下,Co₃O₄-CoAl₂O₄涂层的吸收率最佳,α=0.901,表面为典型的尖晶石结构,晶粒尺寸细小,表面粗糙度为3.519μm。650℃热处理温度下,Co₃O₄-CoAl₂O₄涂层在40 h抗超声震荡实验和20次抗热震实验中,相比其他热处理温度下的样品,质量变化最小,分别为14.9 mg和0.5 mg,且涂层的吸收率维持在0.89左右。结论Co₃O₄-CoAl₂O₄薄膜通过选取合适的热处理温度,可以在改善Co-WC涂层表面状态的同时,一定程度上提高吸收性能。更多还原

【Abstract】 The work aims to improve the absorptance of Co-WC solar selective absorbing coating.Sol-gel method was used to deposit the Co₃O₄-Co Al₂O₄ solar selective absorbing film on the WC-Co coating prepared with high-velocity oxy-fuel（HVOF）spraying.The samples were annealed at different atmospheric temperature.The components of coatings annealed at different temperature were analyzed by X-ray diffraction（XRD）.The microstructure and the surface roughness of the coatings were investigated by field emission scanning electron microscopy（FE-SEM）and surface roughness meter.The performance of Co₃O₄-Co Al₂O₄ coatings was studied by calculating the mass change of the coatings with balance.The element distribution of the Co₃O₄-Co Al₂O₄ coatings was analyzed by energy dispersive spectral（EDS）.The absorptance of coatings was studied by UV-Vis-NIR spectrophotometer.The absorption properties of Co-WC coatings was improved by dipping the Co₃O₄-Co Al₂O₄films.Co₃O₄-Co Al₂O₄ coating annealed at 650℃obtained the excellent absorption withα=0.901.The surface was typical spinel structure with fine grain size and surface roughness of 3.519μm.The mass change of Co₃O₄-Co Al₂O₄ coatings annealed at 650℃was the minimum compared with coatings under other annealing temperatures.The mass change of the coatings was14.9 mg in the experiment of anti-ultrasonic spalling for 40 h and 0.5 mg in the thermal shock resistance for 20 times.At the same time,the absorptance maintained at about 0.89.Co₃O₄-Co Al₂O₄ film can improve the surface state of Co-WC coating and increases the absorption performance through selecting suitable annealing temperature.更多还原