A composite Cr-Al-O spectrally selective solar absorbent coating and preparation method of nano

The present invention discloses a nano composite Cr-Al-O spectrum of solar selective absorbing coating and its method of preparation, the absorbent coating is sequentially deposited on a stainless steel substrate with an infrared reflective layer is high, low oxygen absorbing layer, oxygen absorbing and a high-oxygen layer antireflection layer, a coating method of the present invention is prepared, for using an arc discharge method are sequentially deposited on the substrate layer is highly reflective of infrared, low oxygen absorbing layer, oxygen absorbing layer and hyperoxia antireflection layer, the present invention is coated layer structure design, the absorption ratio of Cr-Al-O-based composite coating prepared as 0.92-0.94, 0.15-0.22 emission rate, good thermal stability and high adhesion. Preparation process approaches pollution while, not only overcome the serious pollution problems in the conventional plating method, while also addressing the thermal stability of the coating and magnetron sputtering a problem of poor high-temperature adhesion and a coating uniformity of deposition techniques difference issue, expected to be applied in the field of high-temperature solar energy utilization.