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3.519 μm。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。

The work aims to improve the absorptance of Co-WC solar selective absorbing coating. Sol-gel method was used to deposit the Co3O4-CoAl2O4 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-CoAl2O4 coatings was studied by calculating the mass change of the coatings with balance. The element distribution of the Co3O4-CoAl2O4 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-CoAl2O4 films. Co3O4-CoAl2O4 coating annealed at 650 ℃ obtained the excellent absorption with α=0.901. The surface was typical spinel structure with fine grain size and surface roughness of 3.519 μm. The mass change of Co3O4-CoAl2O4 coatings annealed at 650 ℃ was the minimum compared with coatings under other annealing temperatures. The mass change of the coatings was 14.9 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-CoAl2O4 film can improve the surface state of Co-WC coating and increases the absorption performance through selecting suitable annealing temperature.