Acid and Alkaline Rain Resistance of AlCrN/AlCrNO/AlCrO Solar Selective Absorbing Coatings Fabricated by Cathodic Arc Ion Plating
摘要
This study evaluated the acid and alkali corrosion resistance of AlCrN/AlCrNO/AlCrO multilayer SSACs fabricated by cathodic arc ion plating (CAIP). Corrosion tests were designed to simulate extreme acid rain and alkaline conditions commonly encountered in northern China. The SSAC samples were synthesized via CAIP and subsequently immersed in H2SO4 solution (pH = 4.0) and Na2CO3 solution (pH = 9.5) for 24 hours, respectively. After exposure, the solar absorptance of all samples remained nearly unchanged at approximately 0.94. Thermal emittance exhibited only minor changes, increasing to 0.22 after acid exposure and decreasing to 0.19 after alkali exposure. Comprehensive characterization using SEM, EDS, XPS, XRD, and ICP analyses revealed that the coating’s chemical composition, microstructure, and phase structure were well preserved after corrosion. However, interaction with the corrosive media resulted in a reduction in macro-droplet size along with partial detachment. In conclusion, the AlCrN/AlCrNO/AlCrO SSAC exhibits excellent resistance to both acidic and alkaline environments, and further reduction of macro-droplet content could enhance the coating’s long-term durability.