Thermal aging test of AlCrNO-based solar selective absorbing coatings prepared by cathodic arc plating

• AlCrNO-based solar selective absorbing coating is made by cathodic arc plating.
• Absorptance/emittance of the coating is 0.93/0.20.
• The coating was annealed at 500 °C for 100 h in the atmosphere.
• After annealing, absorptance/emittance of the coating is 0.94/0.22.
• The CrN content, the grain size, and the surface roughness were the factors which influenced the solar selective of the coating.

A novel AlCrNO-based solar selective absorbing coating was prepared by cathodic arc plating. The coating exhibited excellent selective absorbing properties with an absorptance of 0.93 and an emittance of 0.20. To test the in air thermal stability of this coating, the sample was annealed at 500 °C for 100 h in air. Experimental results indicated that the coating was highly stable in air at 500 °C, as the absorptance/emittance of the coating kept almost unchanged (0.94/0.22) after 100 h annealing. The microstructure of the coating was investigated by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), atomic force microscope (AFM), and X-ray diffraction (XRD).