AbstractIntense solar radiation and internal heat generation determine the equilibrium temperature of an in-orbit spacecraft. Thermal control coatings with low solar absorptance and high thermal emittance effectively maintain the thermal equilibrium within safe operating limits for exposed, miniaturized and highly integrated components. A novel ceramic coating with high thermal emittance and good adhesion was directly prepared on the Mg substrate using an economical process of controlled plasma electrolytic oxidation (PEO) in the electrolyte containing ZnSO4. XRD and XPS results showed that this coating was mainly composed of the MgO phase as well as an unusual ZnO crystalline phase. The adhesive strength between the coating and substrate determined by a pull-off test revealed an excellent adhesion. Thermal and optical properties test revealed that the coating exhibited a high infrared emittance of 0.88 (2–16µm) and low solar absorptance of 0.35 (200–2500nm). The result indicated that the formation of ZnO during the PEO process played an important role in the improvement of the coating emittance. The process developed provides a simple surface method for improving the thermal emittance of Mg alloy, which presents a promising application prospect in the thermal management of the spacecraft.

    HighlightsA thermal control coating with low αs and high ε on Mg alloy was prepared.The participation of Zn ions greatly improved the ε of the PEO coating.The coating was mainly composed of MgO and ZnO.


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    Title :

    In-situ grown MgO-ZnO ceramic coating with high thermal emittance on Mg alloy by plasma electrolytic oxidation


    Contributors:
    Li, Hang (author) / Lu, Songtao (author) / Qin, Wei (author) / Wu, Xiaohong (author)

    Published in:

    Acta Astronautica ; 136 ; 230-235


    Publication date :

    2017-03-22


    Size :

    6 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




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