CN-117626165-B - High-temperature-resistant abradable seal coating structure and preparation process thereof

Abstract

The invention discloses a high-temperature-resistant abradable seal coating structure and a preparation process thereof, wherein the process comprises the steps of firstly, preprocessing a substrate; preparing an alloy bonding layer on a substrate by plasma spraying or supersonic flame spraying, preparing a polyester honeycomb structure by Fused Deposition Modeling (FDM), preheating the substrate to fix the substrate on the substrate, preparing an interface flame-retardant layer by plasma spraying, preparing an abradable surface layer by plasma spraying, and treating at high temperature to obtain the abradable seal coating structure with the honeycomb structure. According to the invention, the polyester honeycomb is introduced into the sealing coating through Fused Deposition Modeling (FDM), and the pores of the honeycomb structure are constructed through heat treatment, so that the strain tolerance of the sealing coating is improved, the abradability is improved, the heat insulation and erosion resistance of the sealing coating are ensured, the performance and service life of the abradable sealing coating are obviously improved, and the sealing coating is suitable for the sealing field between the blade tip and the casing of an aeroengine.

Inventors

• ZHANG CHONG
• XIANG JIAYI
• WEN QIFAN

Assignees

• 西北有色金属研究院

Dates

Publication Date

20260512

Application Date

20231204

Claims (6)

1. 1. The preparation process of the high-temperature-resistant abradable seal coating structure is characterized by comprising the following steps of: step one, carrying out sand blasting and degassing pretreatment on a matrix; Preparing an alloy bonding layer on the substrate pretreated in the first step through plasma spraying or supersonic flame spraying to obtain a substrate with the alloy bonding layer; Preparing a polyester honeycomb structure through Fused Deposition Modeling (FDM), preheating the matrix with the alloy bonding layer obtained in the second step, and fixing the polyester honeycomb structure on the alloy bonding layer in parallel according to regular hexagonal grids to obtain the matrix with the polyester honeycomb structure; Step four, preparing an interface flame-retardant layer on the surface of the matrix with the polyester honeycomb structure obtained in the step three through plasma spraying; Step five, preparing an abradable surface layer on the surface of the interface flame-retardant layer prepared in the step three through plasma spraying to obtain a structural member to be treated; And step six, carrying out high-temperature treatment on the structural member to be treated obtained in the step five to enable the polyester honeycomb structure to be melted and volatilized, and forming an abradable seal coating structure with the honeycomb structure on the substrate.
2. 2. The process for preparing the high-temperature-resistant abradable seal coating structure according to claim 1, wherein in the third step, printing process parameters for preparing the polyester honeycomb structure by Fused Deposition Modeling (FDM) are extrusion temperature 450-480K, platform temperature 320-330K, printing speed 20-50 mm/s, minimum nozzle diameter 0.1mm and layer thickness 0.1-0.2 mm.
3. 3. The process for preparing the high-temperature-resistant abradable seal coating structure according to claim 1, wherein the preheating temperature in the step three is 400-500K, and the heat preservation time is 10min.
4. 4. The process for preparing the high-temperature-resistant abradable seal coating structure according to claim 1, wherein the plasma spraying process parameters in the second, fourth and fifth steps are 130V-135V, 400A-420A, 0.7 MPa-0.8 MPa, 100 mm-120 mm in spraying distance, compressed air and Ar gas as spraying air sources, 25.4L-min -1 as main air pressure air flow and 220L-min -1 as auxiliary Ar gas air flow.
5. 5. The process for preparing the high-temperature-resistant abradable seal coating structure according to claim 1, wherein in the sixth step, the high-temperature treatment is to put a structural member to be treated into a muffle furnace, and keep the temperature at 600 ℃ for 2-3 h.
6. 6. A high temperature resistant abradable seal coating structure prepared by the process of any one of claims 1-5, wherein the total thickness of the high temperature resistant abradable seal coating structure is 0.8 mm-1.1 mm, wherein the thickness of the alloy bonding layer is 100 μm-200 μm, the thickness of the interface flame retardant layer is 300 μm-400 μm, and the thickness of the abradable surface layer is 400 μm-500 μm.

Description

High-temperature-resistant abradable seal coating structure and preparation process thereof Technical Field The invention belongs to the technical field of gas turbines, and particularly relates to a high-temperature-resistant abradable seal coating structure and a preparation process thereof. Background With the development of the aviation industry, in order to meet the performance requirements of high thrust, high thrust-weight ratio, high efficiency and high reliability, the vortex temperature of the aero-engine is also continuously increased. Titanium alloys are used in large scale for the production of engine blades or other high strength parts such as cases, stators, etc. due to their high specific strength, high corrosion resistance and heat resistance. However, during the operation of the engine, due to the influence of thermal expansion difference, machining errors of parts and assembly tolerance, the collision friction of the casing and the engine blade causes the temperature of the titanium alloy to rise and burn, thus causing great economic and safety hazards. The abradable coating is prepared on the surfaces of the casing, the stator and the like at the present stage, so that the coating can be actively abraded when being in opposite abrasion with the rotor component, and therefore, under the condition of ensuring that a minimum gap exists between the rotor and the stator, the engine blade is protected from being abraded, and the gas circuit sealing is completed, and the abradable coating has important significance in the aspects of reducing oil consumption, improving efficiency and running safety. With the improvement of the performance requirements of an aeroengine, the working environment of the aeroengine is increasingly severe, the single-function titanium fire-resistant abradable seal coating is difficult to meet the service requirements, and the temperature of the air flow heated by the combustion chamber at the present stage can reach more than 800K-1000K, so that the abradable surface layer cannot work for a long time at such high temperature, and therefore, a thermal barrier coating needs to be prepared between the abradable coating and the metal bonding layer to serve as a part of the seal coating. However, after a certain service time, a thermal growth oxide layer (TGO) is generated between the ceramic layer and the adhesive layer in a high-temperature environment, so that the problems of coating breakage or spalling and the like can occur. Therefore, long-life stable service is the basis for the thermal barrier coating to play a role in heat insulation. It is therefore of great significance how to improve the strain tolerance of the thermal barrier coating to improve the thermal shock resistance and lifetime of the composite coating. When the abradable seal coating is prepared, the abradable surface layer is mainly composed of Ni-diatomite, niCr-graphite and NiCrAl-bentonite, so that labyrinth seal is carried out on the surface of the air compressor to reduce leakage of high-pressure air flow in the engine, and air channel seal is completed. Meanwhile, under the wearing service condition of the sealing coating, the sealing coating is required to have high grindability and high erosion resistance, but the higher the hardness is, the worse the grindability is, the stronger the erosion resistance is, and aiming at the contradictory relation between the two, how to enable the coating to have high grindability and good erosion resistance is also a key problem for developing the high-performance sealing coating. Disclosure of Invention The invention aims to solve the technical problem of providing a preparation process of a high-temperature-resistant abradable seal coating structure aiming at the defects of the prior art. According to the method, the polyester honeycomb is introduced into the sealing coating through Fused Deposition Modeling (FDM), and pores of a honeycomb structure are formed through heat treatment, so that the sealing coating has a strain tolerance in the vertical direction, the hardness of the sealing coating is reduced, and meanwhile, the small honeycomb structure enables gas in the sealing coating to flow, so that the erosion resistance of the sealing coating is ensured, the performance and service life of the abradable sealing coating are obviously improved, and the problems of limited strain tolerance and contradiction between wear resistance and erosion resistance of the coating in the prior art are solved. In order to solve the technical problems, the invention adopts the technical scheme that the preparation process of the high-temperature-resistant abradable seal coating structure is characterized by comprising the following steps of: step one, carrying out sand blasting and degassing pretreatment on a matrix; Preparing an alloy bonding layer on the substrate pretreated in the first step through plasma spraying or supersonic flame spraying to obtain a substrat