| SHAO Hao,ZENG Xian,LI Qing-yu,LIU Fu-sheng,LIU Tong-zhi,CHENG Xu-dong.Preparation and Properties of Co-Cr3C2-WC/Al2O3 Solar Selective Absorbing Coatings[J],49(6):138-145 |
| Preparation and Properties of Co-Cr3C2-WC/Al2O3 Solar Selective Absorbing Coatings |
| Received:November 25, 2019 Revised:June 20, 2020 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2020.06.016 |
| KeyWord:Co-Cr3C2-WC/Al2O3 selective absorbing coating optical performance thermal stability high velocity oxygen-fuel spraying Sol-Gel method |
| Author | Institution |
| SHAO Hao |
Wuhan University of Technology, Wuhan , China |
| ZENG Xian |
Wuhan University of Technology, Wuhan , China |
| LI Qing-yu |
Wuhan University of Technology, Wuhan , China |
| LIU Fu-sheng |
Wuhan University of Technology, Wuhan , China |
| LIU Tong-zhi |
Wuhan University of Technology, Wuhan , China |
| CHENG Xu-dong |
Wuhan University of Technology, Wuhan , China |
|
| Hits: |
| Download times: |
| Abstract: |
| The work aims to study the spectral emission and absorption properties of different Co-Cr3C2-WC absorbing layers and prepare Al2O3 anti-reflection films on the surface of the absorbing layer to obtain a novel mid-high temperature cermet-based solar selective absorbing coating. The Co-Cr3C2-WC absorbing layers were deposited on the stainless steel by high velocity oxygen-fuel spraying technology (HVOF), and the components were optimized. The Al2O3 anti-reflection films were then prepared on the surface of the absorbing layer by Sol-Gel method. The phase composition, elemental valence and micro-structure of the coatings were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), separately. The root mean square roughness was measured by a surface roughness meter. The spectral reflectance of the coatings in the UV-Vis-NIR and far infrared bands was measured by Fourier infrared spectrometer and UV-Vis-NIR spectrophotometer, respectively. 90Co-5Cr3C2-5WC (wt.%) absorbing layer had the highest quality factor (α/ԑ=0.805/0.308). In addition, the absorptance of the coating increased to 0.903, and the emittance decreased to 0.278 after Al3O2 anti-reflection films were added on the surface. The coating surface was dense and uniform and the roughness was reduced to 1.109 μm. After 100 hours of heat treatment at 750 ℃ in air, the absorptance of the coating increased to 0.910 and the emittance was 0.315, indicating stable selective absorption performance. The 90Co-5Cr3C2-5WC absorbing layer effectively improves the surface state of the thermal sprayed coating and reduces the emittance of the absorbing layer while maintaining a high absorption performance. The Al2O3 anti-reflection film further improves the absorptance of the composite coating by increasing the transmittance of short-wave light and sealing effect, thus enhancing the selective absorption and high-temperature serviceability. Therefore, such coating is expected to be used as a selective absorbing coating in mid-high temperature solar collector system. |
| Close |
|
|
|