AZO改性Y_(2)O_(3)-ZnO-Al_(2)O_(3)热控涂层性能分析

The performance of AZO conductive film modified Y_(2)O_(3)-ZnO-Al_(2)O_(3) coatings as a thermal control material

为解决铝合金表面液相等离子体电解氧化(PEO)涂层(Y_(2)O_(3)-ZnO-Al_(2)O_(3))导电性差而导致的静电效应,对其进行表面改性处理。采用原子层沉积(ALD)技术在铝合金表面PEO涂层原位沉积铝掺杂氧化锌(AZO)导电薄膜以提高PEO涂层的导电性。对AZO改性PEO涂层的相组成和表面微观结构进行分析;对不同沉积温度下所得复合涂层的电阻率、载流子浓度和迁移率,以及沉积前后的热控性能、耐腐蚀性进行测量分析。结果表明:AZO导电薄膜均质连续致密地沉积在PEO涂层表面;当沉积温度为150℃时,AZO@Y_(2)O_(3)-ZnO-Al_(2)O_(3)复合涂层的电阻率为1.15×10^(-4)Ω·cm,载流子浓度为1.8×10^(20)cm^(-3),太阳吸收比为0.409,发射率为0.892,且抗电化学腐蚀性能良好,能够满足航天器热控涂层在空间环境应用的技术要求。

In order to eliminate an electrostatic effect due to the poor conductivity of the Y_(2)O_(3)-ZnO-Al_(2)O_(3) coatings prepared by liquid-phase plasma electrolytic oxidation(PEO)on the surfaces of the aluminum alloy.A modification is made by the aluminum-doped zinc oxide(AZO)conductive film,deposited through the atomic layer deposition(ALD)technique in situ on the PEO coating to improve the overall conductivity.The phase composition and surface microstructure of the resulting AZO@Y_(2)O_(3)-ZnO-Al_(2)O_(3) coatings are analyzed.Meanwhile,the conductive property including the resistivity,the carrier concentration,and the mobility,as well as thermal control and anticorrosion performance of the composite coatings obtained at different deposition temperatures are measured.It is shown that the AZO conductive film deposited on the surface of the PEO coating is uniform,continuous and dense.When the deposition temperature is 150℃,the AZO@Y_(2)O_(3)-ZnO-Al_(2)O_(3) composite coating has an excellent charge conductivity with a resistivity of 1.15×10^(-4)Ω·cm and the carrier concentration of 1.8×10^(20) cm^(-3).In addition,the AZO@Y_(2)O_(3)-ZnO-Al_(2)O_(3) coating has excellent anticorrosion and thermal control properties with a solar absorptivity of 0.409 and an emissivity of 0.892,which can meet technical requirements for spacecraft thermal control coatings in space environments.