在不明显升高Al-聚氨酯(PU)复合涂层红外发射率的前提下,通过酸蚀Al粉提高Al粉表面粗糙度的方法来明显降低涂层的光泽度。系统研究了Al粉酸蚀时间对Al-PU复合涂层的微结构、光泽度、红外发射率及力学性能的影响。结果表明:Al粉酸蚀可明显降低涂层的光泽度,酸蚀10min即可使涂层的光泽度从20.1降低为13.0,而Al粉酸蚀对涂层的微结构基本没有影响,对涂层发射率的影响非常有限,酸蚀50min仅使涂层的发射率从0.208增大为0.254,仍然具有较低的发射率。酸蚀20min可使涂层同时具有较低的光泽度和发射率,其值分别为12.8和0.228。涂层的力学性能对Al粉酸蚀处理并不敏感,处理前后涂层的硬度、附着力和耐冲击强度等力学性能分别可达到3H、1级和50kg·cm。 Under the premise of not increasing the infrared emissivity of the Al-PU (PU) composite coating, the surface roughness of the Al powder is improved by etching the Al powder to reduce the gloss of the coating obviously. The effects of Al powder etching time on microstructure, gloss, infrared emissivity and mechanical properties of Al-PU composite coating were studied systematically. The results showed that: Al powder etching can significantly reduce the gloss of the coating, acid etching 10min to make the coating gloss reduced from 20.1 to 13.0, and Al powder etching on the microstructure of the coating had no effect on the coating The influence of layer emissivity is very limited. Etching for 50 minutes only increases the emissivity of the coating from 0.208 to 0.254, and still has lower emissivity. Acid etching 20min at the same time the coating can have a lower gloss and emissivity, the value was 12.8 and 0.228. The mechanical properties of the coating are not sensitive to Al powder etching treatment. The hardness, adhesion and impact strength of the coating before and after treatment can reach 3H, 1 and 50kg · cm, respectively.