A Zn-Ni coating with both high electrical conductivity and infrared emissivity prepared by hydrogen evolution method

Publication date: 30 April 2017
Source:Applied Surface Science, Volume 402
Author(s): Jiacheng Guo, Xingwu Guo, Wenbin Xu, Zhicheng Zhang, Jie Dong, Liming Peng, Wenjiang Ding
A Zn-Ni coating with both high electrical conductivity and infrared emissivity was prepared by hydrogen evolution method in order to satisfy the demand of thermal control in space. The maximum infrared emissivity of 0.91 was obtained, meanwhile the electrical resistivity is lower than 0.01mΩ/cm. The infrared emissivity of the coating obtained from the experimental result is proportional to the projected area of pores per unit area in the coating. The addition of NH4SCN in the bath can obviously increase the projected area of pores per unit area in the coating and lead to the formation of NiO and ZnO compounds, which further increase the infrared emissivity of the coating. The porous hierarchical structure of Zn-Ni coating can further improve the infrared emissivity, and the infrared emissivity can be tuned by changing the projected area of pores in the coating. Based on the experimental results, a mathematical relationship between infrared emissivity and the projected area of pores per unit area is established. The bond strength and the mass of volatiles of the design of coatings satisfy the technical standard demanded by the satellites in space.

Graphical abstract

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