A high temperature resistant low ablation coating and its preparation method

Abstract

The invention discloses a high-temperature resistant low-ablation coating. The high-temperature resistant low-ablation coating comprises an antioxidant transition bottom layer, a heat-absorption low-ablation intermediate layer and a low-ablation radiation heat dissipation surface layer from inside to outside, wherein the antioxidant transition bottom layer is a silicon oxide layer; the heat-absorption low-ablation intermediate layer comprises ceramic precursor resins, ceramic fibers, ceramic powder, carbon fibers and resin small balls; the low-ablation radiation heat dissipation surface layer comprises high-temperature resistant resin binders and high-temperature high-radiation fillers. A preparation method of the high-temperature resistant low-ablation coating comprises the following steps of: firstly, preparing perhydrosilazane solution; then brushing the perhydrosilazane solution on a substrate; keeping stand for 10-30 minutes after brushing once; finishing the preparation of the antioxidant transition bottom layer after the substrate is brushed for 1-3 times; preparing intermediate layer slurries and preparing the heat-absorption low-ablation intermediate layer on the surface-dried antioxidant transition layer by means of brushing or air spraying; finally, preparing outer-layer slurries, and finishing the preparation of the low-ablation radiation heat dissipation surface layer on the cured heat-absorption low-ablation intermediate layer by means of brushing or air spraying.

Description

technical field [0001] The invention belongs to the field of surface engineering and relates to a coating and a preparation process thereof. Background technique [0002] Composite materials are structural materials widely used in the aerospace field, with excellent properties such as low density, high specific strength, low thermal expansion coefficient, and thermal shock resistance. However, composite materials are prone to ablation problems at high temperatures, and with the increase of environmental heat flow, ablation problems become more prominent, and their mechanical properties will rapidly decay and lose their bearing capacity. Therefore, it is necessary to prepare a high-temperature-resistant and low-ablation coating on the surface of the composite material, use the coating to isolate heat flow and oxygen, and reduce the temperature of the composite material as much as possible, so as to slow down or prevent the ablation of the composite material and ensure its hig...

AI Technical Summary

Problems solved by technology

These preparation methods are either complicated in process and difficult to uniformly prepare on the surface of large and complex components, or require large-scale equipment and high preparation costs

Moreover, the above-mentioned non-ablative or low-ablative coating also has an important defect, that is, the high-temperature erosion resistance is poor, and high-temperature anti-ablation and anti-erosion cannot be realized at the same time, which also means that the coating system prepared by the above method is difficult to be widely used.

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