太阳能选择性吸收涂层设计及空气高温稳定性测试

Design of solar selective absorption coating and its high temperature stability test in air

使用光学软件TFCalc设计了2种金属陶瓷太阳能选择性吸收涂层,根据反射率曲线,优选出Al–Al2O3复合涂层,并按照设计的最优涂层结构,采用磁控溅射法在铜基体上制备了Al–Al2O3复合涂层。研究了涂层在300°C/3 h热处理前后的结合强度、太阳光反射率和表面形貌。结果表明,经300°C空气高温处理3 h后,涂层临界载荷由11.62 N下降到8.75 N,太阳光谱吸收率由93%(该值与TFCalc模拟结果基本一致)下降到86%。显微分析证实涂层性能下降是由于热处理后,涂层表面不再致密平整所致。

Two types of metal-ceramic solar selective absorption coatings were designed using an optical software TFCalc. An A1-Al2O3 composite coating was optimized based on the reflectance curves, and then prepared on copper substrate by magnetron sputtering, according to the designed optimal coating structure. The bond strength, solar reflectance, and surface morphology of the coatings before and after heat treatment at 300 ℃ for 3 h were studied. The results indicated that the critical load in adhesion strength test for the coating treated in air at 300 ℃ for 3 h is decreased from 11.62 N to 8.75 N, and the solar absorption rate is reduced from 93% （a value closed to that simulated by TFCalc） to 86%. The microscopic analysis proved that the performance degradation of the coating is likely to be caused by the incompact and unsmooth surface as a result of the heat treatment.