One-step preparation method of multi-layer environmental barrier coatings through spark plasma sintering (SPS)

Abstract

The invention relates to a one-step preparation method of multi-layer environmental barrier coatings through spark plasma sintering (SPS). The implementation method disclosed by the invention comprises the following steps of directly preparing an environmental barrier coating material on the surface by taking a silicon carbide fibre reinforced silicon carbide ceramic based composite material (SiC / SiC) as a basal body, carrying out SPS at 1050 DEG C according to different surface materials of the coatings, wherein the heat preservation time is set to 2 min; the pressure in a mould is set to 48 MPa; the temperature increasing rate is set to 50 DEG C / min; and putting the sheeted coating material together with the basal body into the mould so as to directly obtain the SiC / SiC composite material having the multi-layer environmental barrier coatings. The multi-layer environmental barrier coatings are prepared on the basal body material by using the method disclosed by the invention; compared with chemical vapour deposition (CVD), a plasma spraying method, a sol-gel method and the like, the method disclosed by the invention is more convenient; the cost is greatly reduced; the preparation period is shortened; furthermore, the quality of the coatings is controllable; and the prepared coatings are higher in density and excellent in property.

Description

Technical field [0001] This article belongs to the field of coating preparation, and specifically relates to a method for preparing a multilayer environmental barrier coating by spark plasma sintering in one step. The required multilayer composite environmental barrier coating can be prepared in one step by spark plasma sintering. Background technique [0002] With the rapid development of the aviation industry, high thrust-to-weight ratio engines have become the focus of aero-engine development. In order to achieve a major breakthrough in high thrust-to-weight ratio and high efficiency of aero-engines, it is necessary to increase the temperature of the gas in the engine and reduce the structural mass, and the increase in gas temperature will correspondingly increase the surface temperature of the hot end parts of the high-pressure turbine. The surface temperature of the hot-end parts of the high-pressure turbine of the high-thrust-to-weight ratio aero-engine will reach abov...

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Problems solved by technology

[0003] At present, the methods for preparing multilayer environmental barrier coatings include plasma spraying, chemical vapor deposition (CVD), electron beam physical vapor deposition (PVD), sol-gel method, slurry method, sintering method, etc., plasma spraying method The obtained multilayer environmental barrier coating has low density and porosity, and because the spraying temperature is too high, there will be a melting zone on the surface of the coating, and the cost is very high. The vapor deposition method has a long preparation period, which is not conducive to large-scale Batch preparation and high cost, while the coating prepared by the sol-gel method has a large volume shrinkage during heat treatment, insufficient compactness, and high cost. The slurry method is sintered when preparing the environmental barrier coating. The temperature is high, and it is easy to damage the base material. However, the existing sintering method generally needs to add various sintering aids, which itself may affect the performance of the coating.

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