On the Formation of Spectrally Selective Thermal Oxide Coatings on the Surface of Chromium Steel for Use in Solar-Energy DevicesстатьяИсследовательская статья
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Дата последнего поиска статьи во внешних источниках: 30 января 2024 г.
Аннотация:The formation process of spectrally selective coating–absorbers of optical radiation with a high absorption coefficient obtained by thermal oxidation of X18H10T high-chromium steel for 1 h in an air atmosphere at temperatures of 100–900°C has been studied. The composition of the films and their thickness were controlled using diffuse reflection Fourier transform IR spectroscopy and specular reflection spectral reflectometry. It is shown that thick oxide layers (up to 1400 A) with high absorption in a wide range of wavelengths of solar radiation are obtained by thermal oxidation of steel plates at 800–900°C. Unfortunately, thick porous coatings obtained by air oxidation of steel at high temperatures have low mechanical strength, and porous coatings can crack and crumble. Thinner oxide layers (400–800 A) with a low content of chromium oxides, formed during the oxidation of steel at 500–600°С, make it possible to obtain spectrally selective absorption sufficient for the operation of the corresponding optical radiation converters in the visible range. Such layers are much stronger, more compact, have a high optical quality and a multilayer and/or gradient structure, make it possible to form one- and two-layer interference coatings of the required thickness and composition, have high absorption and a pronounced photoelectric response in the spectral regions of visible solar radiation.