High temperature-resistant low-infrared emittance composite coating and preparation method thereof

Abstract

The invention discloses a high temperature-resistant low-infrared emittance composite coating capable of being coated on stainless steel or an alloy. The high temperature-resistant low-infrared emittance composite coating contains three-layer structures, wherein the three-layer structures sequentially include a dispersion barrier layer, a low emittance functional layer and an MgO protective film from inside to outside; the dispersion barrier layer is formed from a ZnO-Al2O3-SiO2 microcrystalline glass coating, and the low emittance functional layer is formed from an Au film. A preparation method of the high temperature-resistant low-infrared emittance composite coating comprises the following steps: firstly uniformly mixing raw material powder, placing into a crucible, then smelting at high temperature, quenching, carrying out ball milling on obtained glass residues, drying, and screening to obtain glass powder; mixing the glass powder and an organic carrier, and carrying out ball milling dispersion to obtain a dispersion barrier layer coating; and uniformly brushing the dispersion barrier layer coating on a substrate material by adopting a brushing method, preparing the Au film on the prepared dispersion barrier layer by adopting a magnetron sputtering method, and then preparing the MgO film to obtain the high temperature-resistant low-infrared emittance composite coating. The high temperature-resistant low-infrared emittance composite coating disclosed by the invention has the advantages of simple preparation process, easiness for operation, excellent product property and low cost.

Description

technical field [0001] The invention belongs to the technical field of functional coatings, and in particular relates to a high-temperature-resistant and low-emission coating with a multilayer structure and a preparation method thereof. Background technique [0002] The infrared detector collects the 3μm-5μm and 8μm-14μm band infrared signals of the target, and then uses the difference in infrared radiation energy between the target and the background to identify the target through imaging. According to the calculation formula of infrared radiation energy difference: In the formula, ε 目 is the infrared emissivity of the target, ε 背 is the infrared emissivity of the background, T 目 is the surface temperature of the target, T 背 As the background temperature, it can be seen that reducing the surface temperature of the target can make the radiation intensity of the target and the background similar, and coating low-emissivity functional coatings on high-temperature componen...

AI Technical Summary

Problems solved by technology

Low-emissivity functional materials include lead oxide coating, bismuth oxide coating, Ni / Au coating prepared by magnetron sputtering, high-quality tin-doped indium oxide (ITO) coating and aluminum-doped zinc oxide (ZAO) coating, etc. Low emissivity can be obtained at room temperature, but at high temperature, there are still defects such as material diffusion between coatings and unstable material properties, resulting in an increase in emissivity of the coating in high temperature environments

However, low emissivity prepared by high temperature resistant binders (such as phosphate glass, gallate glass, fluoride glass, etc.), fillers (such as Al, Au, Ag, etc.) and additives (such as ZnS, ZnSe, GaAs, Ge, etc.) Due to the thermal mismatch of the functional coating, it is easy to cause poor adhesion of the coating, high temperature peeling off, etc.

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