High-temperature-resistant high-bonding-strength low infrared emissivity composite coating, metal alloy material with coating and preparation method of metal alloy material

Abstract

The invention discloses a high-temperature-resistant high-bonding-strength low infrared emissivity composite coating which sequentially comprises a NiCrAlY plasma spraying layer, a ZrO2 plasma spraying layer and ZrO2-Al2O3-SiO2 system containing AgPd alloy glass coating from inside to outside. The surface roughness of a metal alloy material coated with the coating is lower than 2.0 micrometers, the bonding strength of the metal alloy material exceeds 10MPa, the tolerable temperature of the coating is higher than 1000 DEG C, and the average infrared emissivity of the coating in a specified band is less than 0.3. A preparation method of the metal alloy material includes the steps: firstly, performing sand blasting for a base; secondly, sequentially spraying the NiCrAlY layer and the ZrO2 layer on the base by a plasma spraying process; finally, uniformly brushing or printing coatings on the ZrO2 layer, and drying and sintering the coatings to obtain the finished metal alloy material. The metal alloy material can be used in a high-temperature environment, infrared radiation of a high-temperature component is effectively reduced, and the metal alloy material is stable in performance and low in cost.

Description

technical field [0001] The invention relates to the technical field of functional coatings and composite materials thereof, in particular to a composite coating with low infrared emissivity, a metal alloy material and a preparation method thereof. Background technique [0002] The infrared detector collects the infrared signals of the target in the bands of 3 μm to 5 μm (high temperature) and 8 μm to 14 μm (normal temperature), 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: △W=σε 目 T 目 4 -σε 背 T 背 4 , where, 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 is the background temperature. Usually, the surface temperature of the target will be higher than that of the background due to heat generation, etc. 目...

AI Technical Summary

Problems solved by technology

The low-emissivity coating of the organic system is not used at a high temperature, and the service temperature generally does not exceed 400°C, so it is not suitable for use in the harsh environment of high-speed aircraft

The low-emissivity coatings of inorganic systems have a relatively high temperature range, and their temperature resistance can even exceed 1000°C. However, most of the low-emissivity coatings of inorganic systems are not ideal for use in high-temperature environments.

The main reasons for the above problems are: first, most low-emissivity fillers are unstable in high-temperature environments and are prone to migration; second, the metal or alloy materials used in aircraft are easy to diffuse to the infrared coating on the surface at high temperatures. As a result, the coating performance deteriorates; third, the thermal expansion coefficient difference between the coating and the base material (such as aerospace alloy materials) is large, resulting in thermal mismatch, which leads to poor adhesion of the coating and easy peeling off; Four, the existing metal materials such as Au, Pt etc. are expensive, and the cost is higher; the fifth, the preparation process of some existing coatings often needs to be carried out in a harsh environment (such as magnetron sputtering needs to be carried out in a vacuum environment), not only requires high equipment, but also is not suitable for molding and preparing special-shaped complex components

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