High-temperature-resisting, high-bonding-strength and low-infrared-emissivity composite coating and preparation method thereof

Abstract

The invention discloses a high-temperature-resisting, high-bonding-strength and low-infrared-emissivity composite coating and a preparation method thereof. The composite coating comprises a diffusion obstruction layer composed of a devitrified glass coating, a low-emissivity functional layer composed of a devitrified glass containing Au powder, and a MgO protecting film in sequence from the inner layer to the outer layer; during preparation, the raw material powder is uniformly mixed, is smelted at high temperature, is quenched, is subjected to ball milling, and is baked to obtain glass dust; organic carrier and the glass dust are mixed to obtain the diffusion obstruction layer coating; the organic carrier, the Au powder and the glass dust, and conducting ball milling are mixed to obtain low-emissivity functional layer coating after ball billing is carried out; the diffusion obstruction layer coating is brushed on a substrate, and then baking and sintering are carried out to obtain the diffusion obstruction layer; the low-emissivity functional layer coating is brushed onto the diffusion obstruction layer, and baking and sintering are carried out to obtain the low-emissivity functional layer; the magnetic control sputtering method is adopted to prepare the MgO film on the low-emissivity functional layer to complete the preparation of the compound coating. The technical process of the composite coating is simple, the technology efficiency is high, and the product performance is good.

Description

Technical field [0001] The invention belongs to the technical field of functional coating materials, and particularly relates to a high-temperature resistant low-infrared emissivity coating with a multi-layer superimposed structure and a preparation method thereof. Background technique [0002] The infrared detector collects the 3μm~5μm and 8μm~14μm infrared signals of the target, and then uses the difference of infrared radiation energy between the target and the background to identify the target through imaging. According to the calculation formula of the difference of infrared radiation energy: Where ε Item Is the infrared emissivity of the target, ε Back Is the background infrared emissivity, T Item Is the target surface temperature, T Back 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 close, and coating a low-emissivity functional coating on the high-temper...

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 (AZO) coating, etc. Lower emissivity can be obtained in normal temperature environment, but there are still defects such as material diffusion between coatings and unstable material properties in high temperature environment, which leads to the increase of coating emissivity in high temperature environment

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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