M-AlN太阳选择性吸收涂层的研制

A STUDY ON CERMET MATERIAL FOR SELECTIVE ABSORBING SURFACE

为提高在高温条件下选择性吸收涂层的性能 ,采用金属粒子注入介质基体中形成的金属陶瓷 ( cermet)作吸收材料 ,制成金属陶瓷复合薄膜 ,它具有优良的光学性能和热稳定性。根据对金属陶瓷膜系的光学性能进行理论计算的结果 ,采用磁控多靶反应共溅射的方法对膜系进行反演寻优工艺实验。实验结果表明 ,优化后的涂层吸收率 α>0 .9,发射率 ε( 35 3K) <0 .1。当温度高于 35 0℃时性能稳定 ,吸收率α变化不大 ,而发射率ε不超过 0 .1。与多层渐变吸收涂层相比 ,金属陶瓷选择性吸收涂层具有膜系结构简单、高温条件下性能稳定、发射率较低等优点。该涂层适用于低倍聚光真空管集热器。

In order to improve the solar thermal performance of selective coating at high temperature,a compound material——cermet is used.The material consists of dielectric medium and metal particles,which has excellent optical properties and thermal stability.The coating is deposited by co sputtering with three metal targets.The structures of the selective surface have been designed by using numerical modelling calculations.Optimum selective surface has achieved α>0.9,ε(353K)<0.1.Compared with the existing coating on the vacuum tubes the cermet coatings are more stable and have lower emittance at high temperature(350℃～500℃).The new coating is suitable to be used on low concentrate vacuum tube collectors.