A high-temperature corrosion-resistant multi-element complex environmental barrier coating, a preparation method and application thereof

Abstract

The application provides a high-temperature corrosion-resistant multi-element complex environmental barrier coating, which comprises, in sequence, an HfSiO4-Si adhesive layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer and a (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer; RE1, RE2 and RE3 are any three different elements in Lu, Er, Y, Sc, Ho, Nd, Gd and Tm. The high-temperature corrosion-resistant multi-element complex environmental barrier coating in the application has a high-temperature resistance of 1450 DEG C, and has the advantages of excellent water-oxygen resistance, CMAS corrosion resistance, high interface stability and high thermal matching degree with the matrix, and can improve the service reliability of ceramic matrix composite high-temperature parts. The application further provides a preparation method and application of the high-temperature corrosion-resistant multi-element complex environmental barrier coating.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-temperature protective coating materials, and particularly relates to a high-temperature corrosion-resistant multi-element complex environmental barrier coating, a preparation method and application thereof. BACKGROUND

[0002] The ceramic matrix composite material has the characteristics of low density, high temperature bearing, excellent high-temperature mechanical properties, and is expected to replace the traditional high-temperature alloy to become an ideal material of a new generation of high-temperature parts of an aero-engine. In a complex high-temperature gas environment, the service performance of the CMC component is rapidly degraded due to the water vapor-oxygen coupling corrosion. Therefore, a high-temperature and long-life environmental barrier coating (EBC) is needed to improve the stable service performance of the CMC high-temperature part.

[0003] At present, the third generation EBC system with "rare earth silicate as a surface layer, mullite as an intermediate layer and silicon as a bonding layer" can be stably served at 1300 DEG C for a long time. With the continuous increase of the turbine inlet temperature of the aero-engine, the high-temperature corrosion (water-oxygen corrosion, CMAS corrosion, etc.) and interfacial instability of the environmental barrier coating become more and more serious. However, the single-component coating system lacks the ability to control the damage mechanism and failure law under the condition of thermal and mechanical coupling, such as the softening or even melting of the Si layer at 1350 DEG C, the internal cracks of the mullite layer due to the large elastic modulus, the single rare earth silicate cannot simultaneously have the high-temperature corrosion resistance and the low thermal expansion coefficient, and the high-temperature corrosion resistance sharply decreases with the increase of temperature, which cannot meet the comprehensive design requirements of the new generation of EBC.

[0004] Therefore, it is of great significance to develop a new multi-element complex environmental barrier coating system resistant to higher temperature corrosion (1450 DEG C) and break through the improvement limit of the key performance of the single-component coating, so as to prolong the service life of the CMC high-temperature part. SUMMARY

[0005] The application aims to provide a high-temperature corrosion-resistant multi-element complex environmental barrier coating, a preparation method and application thereof. The high-temperature corrosion-resistant multi-element complex environmental barrier coating in the application has the advantages of high-temperature resistance up to 1450 DEG C, high water-oxygen and CMAS corrosion resistance, high interface stability, high thermal matching degree with the substrate, etc., and can improve the service reliability of the ceramic matrix composite material high-temperature part.

[0006] The application provides a high-temperature corrosion-resistant multi-element complex environmental barrier coating, which comprises, in sequence, a HfSiO4-Si bonding layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer and a (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25a HfSiO4-Si bonding layer; the HfSiO4-Si bonding layer is in contact with the substrate material;

[0007] The Mullite-BSAS transition layer comprises Mullite and BSAS, and the BSAS has a chemical formula as shown in formula I: (1-x)BaO·xSrO·Al2O3·2SiO2, 0≤x≤1 formula I;

[0008] (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 In the Yb2SiO5 environmental barrier layer, RE1, RE2 and RE3 are any three different elements from Lu, Er, Y, Sc, Ho, Nd, Gd and Tm.

[0009] Preferably, the mass ratio of Mullite and BSAS is 2:8-8:2.

[0010] Preferably, in the HfSiO4-Si bonding layer, the mass ratio of Si and HfSiO4 is 1:(2-10).

[0011] Preferably, in the Yb2SiO5-Yb2Si2O7 intermediate layer, the mass ratio of Yb2SiO5 and Yb2Si2O7 is 1:1-9:1.

[0012] Preferably, the thickness of the HfSiO4-Si bonding layer is 50-100 μm; the thickness of the Mullite-BSAS transition layer is 50-100 μm; the thickness of the Yb2SiO5-Yb2Si2O7 intermediate layer is 100-150 μm; and the thickness of the Yb2SiO5 environmental barrier layer is 100-200 μm. 0.25 RE1 0.25 RE2 0.25 RE3 0.25 The thickness of the Yb2SiO5 environmental barrier layer is 100-200 μm.

[0013] The application provides a preparation method of the high-temperature corrosion-resistant multi-element complex environmental barrier coating as described above, comprising the following steps:

[0014] A) pretreating the substrate material;

[0015] B) sequentially preparing a HfSiO4-Si bonding layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer and a Yb2SiO5 environmental barrier layer on the surface of the pretreated substrate material by using an atmospheric plasma spraying technology. 0.25 RE1 0.25 RE2 0.25 RE3 0.25 The Yb2SiO5 environmental barrier layer;

[0016] C) vacuum heat treatment of the coating to obtain a high-temperature corrosion resistant multi-component complex environmental barrier coating.

[0017] Preferably, the substrate material is a ceramic matrix composite substrate.

[0018] The pretreatment comprises sequentially cleaning, sand blasting and plasma jet heating of the substrate material.

[0019] Preferably, in step B), the powder particle size of HfSiO4-Si is 40-150 μm during the atmospheric plasma spraying process for preparing the HfSiO4-Si bonding layer.

[0020] The powder particle size of Mullite-BSAS is 20-80 μm during the atmospheric plasma spraying process for preparing the Mullite-BSAS transition layer.

[0021] The powder particle size of Yb2SiO5-Yb2Si2O7 is 20-100 μm during the atmospheric plasma spraying process for preparing the Yb2SiO5-Yb2Si2O7 intermediate layer.

[0022] The powder particle size of (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 is 20-150 μm during the atmospheric plasma spraying process for preparing the (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer.

[0023] Preferably, in step C), the temperature of the vacuum heat treatment is 1200-1300 °C, the time of the vacuum heat treatment is 4-8 h, the vacuum degree is ≥1×10 -3 Pa and <10×10 -3 Pa.

[0024] The application provides the application of the high-temperature corrosion resistant multi-component complex environmental barrier coating as described above as a ceramic matrix composite surface thermal protection coating in an aero-engine.

[0025] The application provides a high-temperature corrosion resistant multi-component complex environmental barrier coating, which comprises in sequence a HfSiO4-Si bonding layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer and a (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25Yb2SiO5environmental barrier layer; the mass ratio of Yb2SiO5and Yb2Si2O7is 1:1-9:1; the HfSiO4-Si adhesive layer is in contact with the base material; the Mullite-BSAS transition layer comprises Mullite and BSAS, and the mass ratio of Mullite and BSAS is 2:8-8:2; the BSAS has a chemical formula shown in formula I: (1-x)BaO·xSrO·Al2O3·2SiO2, 0≤x≤1; (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 In the Yb2SiO5environmental barrier layer, RE1, RE2 and RE3 are any three different elements in Lu, Er, Y, Sc, Ho, Nd, Gd and Tm.

[0026] Compared with the existing third-generation environmental barrier coating system, the four-layer structure coating in the application has the following advantages:

[0027] (1) The HfSiO4-Si adhesive layer in the multi-element composite environmental barrier coating has good interface bonding with the CMC base material, the main element HfSiO4 phase has a high melting point (~ 2758℃), a thermal expansion coefficient suitable for CMC and a low oxygen diffusion rate, and Si as the second phase can increase the bonding force between the adhesive layer and the base material on the one hand and can self-repair cracks in HfSiO4 on the other hand, thereby improving the service life of the coating at 1400℃;

[0028] (2) The Mullite-BSAS transition layer in the multi-element composite environmental barrier coating has a low thermal conductivity of the main phase Mullite, good chemical compatibility with the HfSiO4-S adhesive layer, and no HfO2-based reactants generated at the interface during service;

[0029] (3) The Yb2SiO5-Yb2Si2O7intermediate layer in the multi-element composite environmental barrier coating has Yb2SiO5 and Yb2Si2O7 mixed in a certain ratio, which is conducive to relieving the mismatch of the thermal expansion coefficient between the coating and the base material and avoiding the through cracks generated during the service of the coating due to thermal mismatch;

[0030] (4) The (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25The multi-component doping is beneficial to further improve the water-oxygen corrosion resistance and CMAS corrosion resistance of Yb2SiO5 at 1450 DEG C, and reduce the thermal conductivity and thermal expansion coefficient of Yb2SiO5, so that better environmental protection and thermal protection effects of the CMC matrix are provided.

[0031] (5) The high-temperature corrosion-resistant multi-component complex environmental barrier coating is prepared by the atmospheric plasma spraying process, and has the advantages of convenient operation, low cost and high deposition efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0033] Figure 1 is a schematic diagram of the cross-sectional structure of the high-temperature corrosion-resistant multi-component complex environmental barrier coating prepared on the surface of the ceramic matrix composite material according to the present application;

[0034] In the drawings, 1 is the ceramic matrix composite material substrate, 2 is the HfSiO4-Si bonding layer, 3 is the Mullite-BSAS transition layer, 4 is the Yb2SiO5-Yb2Si2O7 intermediate layer, and 5 is the (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer;

[0035] Figure 2 is a flow chart of the preparation method of the high-temperature corrosion-resistant multi-component complex environmental barrier coating prepared on the surface of the ceramic matrix composite material in an embodiment of the present application;

[0036] Figure 3 is the surface morphology of the multi-component complex environmental barrier coating in embodiment 1 of the present application;

[0037] Figure 4 is the macroscopic morphology of the coating after water-oxygen corrosion for different times in embodiment 1 of the present application. DETAILED DESCRIPTION

[0038] The present application provides a high-temperature corrosion-resistant multi-component complex environmental barrier coating, which comprises, in sequence, an HfSiO4-Si bonding layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer and a (Yb 0.25 RE1 0.25 RE 2 0.25 RE30.25 )2SiO5 environmental barrier layer; the HfSiO4-Si adhesive layer is in contact with the substrate material;

[0039] The Mullite-BSAS transition layer comprises mullite and BSAS, and the mass ratio of the mullite and the BSAS is 2:8-8:2; the BSAS has a chemical formula shown in formula I: (1-x)BaO·xSrO·Al2O3·2SiO2, 0≤x≤1;

[0040] (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 In the (Yb

[0041] In the present application, the substrate material is preferably a ceramic composite material substrate, i.e., a CMC substrate, and the present application does not have special limitations on the specific components of the substrate material, and any ceramic composite material substrate commonly used in the art can be used.

[0042] In the present application, the HfSiO4-Si adhesive layer is in contact with the substrate material, and in the HfSiO4-Si adhesive layer, the mass ratio of Si and HfSiO4 is preferably 1:(2-10), more preferably 1:(3-8), such as 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, preferably a range value with any of the above values as the upper limit or lower limit; the thickness of the HfSiO4-Si adhesive layer is preferably 50-100 μm, more preferably 60-80 μm. According to the present application, when the mass of Si and HfSiO4 is used according to the above components, the adhesive layer obtained has a lower oxidation rate and a higher service life.

[0043] In the present application, the Mullite-BSAS transition layer is in contact with the HfSiO4-Si adhesive layer, the Mullite-BSAS transition layer comprises Mullite and BSAS, the mass ratio of Mullite and BSAS is preferably 2:8-8:2, more preferably 2:2-8:2, such as 2:2, 3:2, 4:2, 5:2, 6:2, 7:2, 8:2, preferably the range value with any of the above values as the upper limit or lower limit. The BSAS has the chemical formula shown in formula I: (1-x)BaO·xSrO·Al2O3·2SiO2, 0≤x≤1 formula I; wherein 0.1≤x≤1, such as x is 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.75, 0.8, 0.9, 1, preferably the range value with any of the above values as the upper limit or lower limit; the thickness of the Mullite-BSAS transition layer is 50-100 μm, more preferably 60-80 μm. According to the research of the present application, when the mass of Mullite and BSAS is used according to the above composition, the transition layer and the adhesive layer obtained have good chemical compatibility.

[0044] In the present application, in the Yb2SiO5-Yb2Si2O7 intermediate layer, the mass ratio of Yb2SiO5 and Yb2Si2O7 is preferably 1:1-9:1, more preferably 1:1-7:3, such as 1:1, 5:4, 4:3, 3:2, 2:1, 7:3, preferably the range value with any of the above values as the upper limit or lower limit; the thickness of the Yb2SiO5-Yb2Si2O7 intermediate layer is preferably 100-150 μm, more preferably 120-140 μm. According to the research of the present application, when the mass of Yb2SiO5 and Yb2Si2O7 is used according to the above composition, the intermediate layer obtained has a thermal expansion coefficient matched with the CMC matrix and excellent corrosion resistance.

[0045] In the present application, the (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer, RE1, RE2 and RE3 are preferably any three different elements selected from Lu, Er, Y, Sc, Ho, Nd, Gd and Tm, and the (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 The thickness of the (Yb

[0046] The application further provides a preparation method of the high-temperature corrosion-resistant multi-element complex environmental barrier coating.

[0047] A) pretreating the base material;

[0048] B) sequentially preparing a HfSiO4-Si adhesive layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer and a (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer on the surface of the pretreated ceramic matrix composite base by adopting an atmospheric plasma spraying technology;

[0049] C) vacuum heat treating the coating to obtain the high-temperature corrosion-resistant multi-element complex environmental barrier coating.

[0050] In the application, the base material is the same as the base material described above, and the application will not be described here.

[0051] In the application, the pretreatment preferably comprises the following steps:

[0052] 1) placing the base material into acetone for ultrasonic cleaning, and then placing it into an oven for drying at 100-120 DEG C for 15-30 min;

[0053] 2) using 100-300 mesh quartz sand to perform sand blasting treatment on the cleaned ceramic matrix composite base;

[0054] 3) performing plasma jet heating on the sand-blasted ceramic matrix composite base to make the surface temperature reach 400-600 DEG C.

[0055] In the application, the ultrasonic cleaning time is preferably 10-30 min, and more preferably 15-20 min.

[0056] In the application, the drying temperature is preferably 100-120 DEG C, and more preferably 110-115 DEG C, and the drying time is preferably 15-30 min, and more preferably 20-25 min.

[0057] In the application, in order to increase the surface roughness of the ceramic matrix composite and further improve the bonding force between the adhesive layer and the base, the cleaned base is subjected to sand blasting treatment, the mesh number of the quartz sand used for sand blasting is preferably 100-300 mesh, and more preferably 150-250 mesh; the sand blasting pressure is preferably 0.1-0.3 MPa, and more preferably 0.2-0.3 MPa; and the sand blasting time is preferably 10-30 s, and more preferably 15-25 s.

[0058] In the present application, the plasma jet heating is a common technical means in the art. After the plasma jet heating, the surface of the substrate material is heated to 400-600°C, preferably 500-600°C.

[0059] After obtaining the pretreated substrate material, the present application uses the atmospheric plasma spraying technology to prepare HfSiO4-Si adhesive layer, Mullite-BSAS transition layer, Yb2SiO5-Yb2Si2O7 intermediate layer and (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer on the surface in sequence, to obtain a multi-element composite coating. The specific steps and parameters are as follows:

[0060] In the process of preparing HfSiO4-Si adhesive layer by atmospheric plasma spraying, argon and hydrogen are used as plasma. The flow rate of argon is preferably 40-60 L / min, more preferably 45-55 L / min, such as 40 L / min, 45 L / min, 50 L / min, 55 L / min, 60 L / min, and preferably a range value with any of the above values as the upper or lower limit. The flow rate of hydrogen is preferably 5-12 L / min, more preferably 8-10 L / min, such as 5 L / min, 6 L / min, 7 L / min, 8 L / min, 9 L / min, 10 L / min, 11 L / min, 12 L / min, and preferably a range value with any of the above values as the upper or lower limit. The spraying distance is preferably 80-150 mm, more preferably 100-120 mm, such as 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, and preferably a range value with any of the above values as the upper or lower limit. The spraying current is preferably 300-500 A, more preferably 400-450 A, such as 300 A, 350 A, 400 A, 450 A, 500 A, and preferably a range value with any of the above values as the upper or lower limit. The powder feeding rate is preferably 10-20%, more preferably 15-18%, such as 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, and preferably a range value with any of the above values as the upper or lower limit. The powder particle size of HfSiO4-Si is preferably 40-150 μm, more preferably 50-120 μm, such as 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, and preferably a range value with any of the above values as the upper or lower limit.

[0061] The HfSiO4-Si powder in this invention can be prepared by spray granulation of HfSiO4 and Si respectively, followed by mechanical mixing. This process is a conventional process known to those skilled in the art, and this invention does not impose any special limitations on it; as long as the powder of this composition can be obtained, it is acceptable.

[0062] In the process of preparing the Mullite-BSAS transition layer by atmospheric plasma spraying, argon and hydrogen are used as plasma. The flow rate of argon is preferably 40-60 L / min, more preferably 45-55 L / min, such as 40 L / min, 45 L / min, 50 L / min, 55 L / min, 60 L / min, preferably within the range of any of the above values ​​as the upper or lower limit; the flow rate of hydrogen is preferably 5-12 L / min, more preferably 8-10 L / min, such as 5 L / min, 6 L / min, 7 L / min, 8 L / min, 9 L / min, 10 L / min, 11 L / min, 12 L / min, preferably within the range of any of the above values ​​as the upper or lower limit; the spraying distance is preferably 100-200 mm, more preferably 120-180 mm, such as 100 mm, 110 mm, 120 mm, 130 mm. The preferred values ​​are 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, and 200mm, with any of the above values ​​as the upper or lower limit. The spraying current is preferably 400-600A, more preferably 500-550A, such as 400A, 450A, 500A, 550A, and 600A, with any of the above values ​​as the upper or lower limit. The powder feeding rate is preferably 10-30%, more preferably 15-25%, such as 10%, 15%, 20%, 25%, and 30%, with any of the above values ​​as the upper or lower limit. The powder particle size of Mullite-BSAS is preferably 20-80μm, more preferably 30-70μm, such as 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, and 80μm, with any of the above values ​​as the upper or lower limit.

[0063] The Mullite-BSAS in this invention can be prepared by spray granulation of Mullite and BSAS separately, followed by mechanical mixing. This process is a conventional process known to those skilled in the art, and this invention does not impose any special limitations on it, as long as the powder of this component can be obtained.

[0064] In the process of preparing Yb2SiO5-Yb2Si2O7 intermediate layer by atmospheric plasma spraying, argon and hydrogen are used as plasma, the flow rate of argon is preferably 40-60 L / min, more preferably 45-55 L / min, such as 40 L / min, 45 L / min, 50 L / min, 55 L / min, 60 L / min, preferably a range value with any of the above values as the upper limit or lower limit; the flow rate of hydrogen is preferably 6-15 L / min, more preferably 8-12 L / min, such as 6 L / min, 7 L / min, 8 L / min, 9 L / min, 10 L / min, 11 L / min, 12 L / min, 13 L / min, 14 L / min, 15 L / min, preferably a range value with any of the above values as the upper limit or lower limit; the spraying distance is preferably 100-200 mm, more preferably 120-180 mm, such as 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, preferably a range value with any of the above values as the upper limit or lower limit; the spraying current is preferably 500-800 A, more preferably 600-700 A, such as 500 A, 550 A, 600 A, 650 A, 700 A, 750 A, 800 A, preferably a range value with any of the above values as the upper limit or lower limit; the powder feeding rate is preferably 5-25%, more preferably 10-20%, such as 5%, 10%, 15%, 20%, 25%, preferably a range value with any of the above values as the upper limit or lower limit; the powder particle size of Yb2SiO5-Yb2Si2O7 is preferably 20-100 μm, more preferably 40-80 μm, such as 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, preferably a range value with any of the above values as the upper limit or lower limit.

[0065] Yb2SiO5-Yb2Si2O7 in the application can be prepared by spraying Yb2SiO5 and Yb2Si2O7 respectively, then mechanically mixing uniformly. The process is a conventional process known to those skilled in the art, and the application does not make special limitations thereon, and powders with the composition can be obtained.

[0066] atmospheric plasma spraying (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25)2SiO5, the flow rate of argon is preferably 40-60 L / min, more preferably 45-55 L / min, such as 40 L / min, 45 L / min, 50 L / min, 55 L / min, 60 L / min, preferably a range with any of the above values as the upper or lower limit; the flow rate of hydrogen is preferably 6-12 L / min, more preferably 8-10 L / min, such as 6 L / min, 7 L / min, 8 L / min, 9 L / min, 10 L / min, 11 L / min, 12 L / min, preferably a range with any of the above values as the upper or lower limit; the spraying distance is preferably 100-200 mm, more preferably 120-180 mm, such as 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, preferably a range with any of the above values as the upper or lower limit; the spraying current is preferably 500-800 A, more preferably 600-700 A, such as 500 A, 550 A, 600 A, 650 A, 700 A, 750 A, 800 A, preferably a range with any of the above values as the upper or lower limit; the powder feeding rate is preferably 5-25%, more preferably 10-20%, such as 5%, 10%, 15%, 20%, 25%, preferably a range with any of the above values as the upper or lower limit;(Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 The powder particle size of (Yb

[0067] (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 can be prepared by ball milling Yb2O3, RE12O3, RE22O3, RE32O3 and SiO2 first, then sintering in solid phase, and then spray granulation. This process is a conventional process known to those skilled in the art, and the present application does not make special limitations thereon, and powders with the above composition can be obtained.

[0068] After the above multilayer structure is prepared by spraying, the coating is subjected to vacuum heat treatment to obtain a high-temperature corrosion-resistant multicomponent complex environmental barrier coating.

[0069] In the present application, the temperature of the vacuum heat treatment is preferably 1200-1300 DEG C, more preferably 1230-1280 DEG C, such as 1200 DEG C, 1210 DEG C, 1220 DEG C, 1230 DEG C, 1240 DEG C, 1250 DEG C, 1260 DEG C, 1270 DEG C, 1280 DEG C, 1290 DEG C, 1300 DEG C, preferably a range with any of the above values as the upper or lower limit; the time of the vacuum heat treatment is preferably 4-8 h, more preferably 5-6 h, and the vacuum degree is preferably 1x10 -3 Pa and <10x10 -3 Pa, more preferably 2x10 -3 Pa and 8x10 -3 Pa, such as 1x10 -3 Pa, 2x10 -3 Pa, 3x10 -3 Pa, 4x10 -3 Pa, 5x10 -3 Pa, 6x10 -3 Pa, 7x10 -3 Pa, 8x10 -3 Pa, 9x10 -3 Pa, preferably a range with any of the above values as the upper or lower limit.

[0070] The present application also provides the application of the high-temperature corrosion-resistant multi-element complex environmental barrier coating described above as a surface thermal protection coating of a ceramic matrix composite high-temperature part in an aero-engine.

[0071] In the present application, the high-temperature part is preferably a CMC guide vane, and the high-temperature corrosion-resistant multi-element complex environmental barrier coating has the advantages of high thermal matching degree with the matrix material, excellent water-oxygen and CMAS corrosion resistance, and good interface compatibility, and can improve the service reliability of the CMC guide vane surface.

[0072] Compared with the third-generation environmental barrier coating system, the present application adds a high-entropy rare earth monosilicate environmental barrier layer by utilizing the multi-component synergistic effect in high-entropy materials on the basis of doping and modifying the materials of each layer. The four-layer structure coating in the present application has the following advantages:

[0073] (1) The HfSiO4-Si adhesive layer in the multi-element complex environmental barrier coating has good interface bonding with the CMC substrate, the main element HfSiO4 phase has a high melting point (~ 2758℃), a thermal expansion coefficient suitable for CMC, and a low oxygen diffusion rate, and Si as a second phase can increase the bonding force between the adhesive layer and the substrate, and can also repair cracks in HfSiO4, thereby improving the service life of the coating at 1400℃; (2) The Mullite-BSAS transition layer in the multi-element complex environmental barrier coating, the main phase Mullite has low thermal conductivity and good chemical compatibility with the HfSiO4-S adhesive layer, and no HfO2-based reactants will be generated at the interface during service; the second phase BSAS has low elastic modulus, which is beneficial to relieve the accumulation of thermal stress during cold and hot cycles;

[0074] (3) The Yb2SiO5-Yb2Si2O7 intermediate layer in the multi-element complex environmental barrier coating, Yb2SiO5 and Yb2Si2O7 are mixed in a certain proportion, which is beneficial to relieve the mismatch of the thermal expansion coefficient between the coating and the substrate, and avoid the through cracks generated during the service of the coating due to thermal mismatch;

[0075] (4) The (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer, the multi-element doping is beneficial to further improve the water and oxygen corrosion resistance and CMAS corrosion resistance of Yb2SiO5 material at 1450℃, while reducing the thermal conductivity and thermal expansion coefficient of Yb2SiO5 material, providing better environmental protection and thermal protection effect for CMC substrate.

[0076] (5) The high-temperature corrosion-resistant multi-element complex environmental barrier coating is prepared by atmospheric plasma spraying process, which has the advantages of easy operation, low cost and high deposition efficiency.

[0077] In order to further illustrate the present application, the following embodiments are described in detail, but it should not be understood as limiting the scope of the present application.

[0078] The HfSiO4, Si, Mullite, BSAS, Yb2SiO5, Yb2Si2O7, Yb2O3, Lu2O3, Er2O3, Sc2O3, Y2O3 powders used in the following examples and comparative examples are commercially available. For example, the Si, Mullite, BSAS, Yb2SiO5, Yb2Si2O7, Yb2O3, Lu2O3, Er2O3, Sc2O3, Y2O3 powders in the present examples are purchased from Hunan Zhaoyi Thermal Spraying Material Co., Ltd., and the HfSiO4 and (Yb 0.25 Lu 0.25 Er 0.25 Sc 0.25 )2SiO5 powders are prepared by high-temperature solid-phase sintering + spray granulation process by Changsha College on commission. This powder preparation process is known to those skilled in the art.

[0079] High-temperature water-oxygen corrosion performance test:

[0080] The water-oxygen corrosion resistance test is carried out at 1450°C, 90% H2O-10% O2, 1 atm, until the coating shows obvious peeling (peeling area greater than 10%), which is defined as failure.

[0081] High-temperature CMAS corrosion performance test:

[0082] The CMAS composition is 22CaO-19MgO-14Al2O3-45SiO2, the test temperature is 1400°C, and the test time is 50h.

[0083] Thermal cycle performance test:

[0084] The thermal cycle performance test is carried out at 1450°C, holding for 5 minutes, air cooling for 5 minutes, until the coating shows obvious peeling (peeling area greater than 10%), which is defined as failure.

[0085] Thermal shock performance test:

[0086] The thermal shock performance test is carried out at 1400°C, flame flow speed 0.5 Mach, constant temperature for 120 seconds, air cooling for 30 seconds, until the coating shows obvious peeling (peeling area greater than 10%), which is defined as failure.

[0087] Example 1

[0088] (1) Prepare SiC f / SiC ceramic composite material substrate, size 20mm x 10mm x 10mm, acetone ultrasonic cleaning for 15min, then put into oven and dry for 20min, oven temperature is 110°C.

[0089] (2) Sandblasting the SiC f / SiC substrate before spraying, the sandblasting sand is 220 mesh quartz sand, the sandblasting pressure is 0.3 MPa, and the sandblasting time is 15 s.

[0090] (3) Mounting the SiC f / SiC substrate on the automatic workbench of the atmospheric plasma spraying equipment, and heating the substrate by using the plasma jet to make the surface temperature reach 500 °C.

[0091] (4) Selecting the powder particle size of 9HfSiO4-1Si after spray granulation as 40-150 μm, the powder particle size of 8Mullite-2BSAS (BSAS: 0.75BaO·0.25SrO·Al2O3·2SiO2) as 20-80 μm, the powder particle size of 7Yb2SiO5-3Yb2Si2O7 as 20-100 μm, and the powder particle size of (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 as 20-150 μm. The granulated powder is porous spherical powder. The above four kinds of powder are sequentially added to the powder feeder of the atmospheric plasma spraying equipment.

[0092] (5) Preparing the 9HfSiO4-1Si bond coat layer on the surface of the SiC f / SiC substrate by using the atmospheric plasma spraying method, and adjusting the process parameters as follows: the flow rate of argon is 45 L / min, the flow rate of hydrogen is 10 L / min, the spraying distance is 110 mm, the spraying current is 400 A, and the powder feeding rate is 20%, so that the HfSiO4-Si bond coat layer with a thickness of 50 μm is obtained.

[0093] (6) Preparing the 8Mullite-2BSAS transition layer on the surface of the 9HfSiO4-1Si bond coat layer by using the atmospheric plasma spraying method, and adjusting the process parameters as follows: the flow rate of argon is 50 L / min, the flow rate of hydrogen is 10 L / min, the spraying distance is 140 mm, the spraying current is 530 A, and the powder feeding rate is 25%, so that the 8Mullite-2BSAS transition layer with a thickness of 50 μm is obtained.

[0094] (7) Preparing the 7Yb2SiO5-3Yb2Si2O7 intermediate layer on the surface of the 8Mullite-2BSAS transition layer by using the atmospheric plasma spraying method, and adjusting the process parameters as follows: the flow rate of argon is 50 L / min, the flow rate of hydrogen is 12 L / min, the spraying distance is 120 mm, the spraying current is 600 A, and the powder feeding rate is 25%, so that the 7Yb2SiO5-3Yb2Si2O7 intermediate layer with a thickness of 120 μm is obtained.

[0095] (8) The (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 environmental barrier layer is prepared on the surface of the 7Yb2SiO5-3Yb2Si2O7 interlayer by the atmospheric plasma spraying method, and the process parameters are adjusted as follows: the flow rate of argon is 50 L / min, the flow rate of hydrogen is 10 L / min, the spraying distance is 150 mm, the spraying current is 600 A, and the powder feeding rate is 25%, so that the (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 environmental barrier layer with a thickness of 150 μm is obtained, and the surface morphology is as shown in FIG. 1. Figure 3

[0096] (9) The as-deposited coating is subjected to vacuum heat treatment, and the process parameters are adjusted as follows: the temperature is 1300 ℃, the time is 6 h, and the vacuum degree is 5×10 -3 Pa.

[0097] The high-temperature water-oxygen corrosion performance test is conducted on the environmental barrier coating in Example 1, and the results show that the environmental barrier coating in this example is not peeled off after water-oxygen corrosion for 300 h.

[0098] The high-temperature CMAS corrosion performance test is conducted on the environmental barrier coating in Example 1, and the results show that the reaction layer has a thickness of less than 30 μm, and the CMAS does not penetrate into the coating after corrosion for 50 h.

[0099] The thermal cycle performance test is conducted on the environmental barrier coating in Example 1, and the results show that the thermal shock life of the environmental barrier coating in this example is greater than 650 cycles.

[0100] The thermal shock performance test is conducted on the environmental barrier coating in Example 1, and the results show that the thermal shock life of the environmental barrier coating in this example is greater than 650 cycles.

[0101] Example 2

[0102] The four-layer multi-component composite environmental barrier coating is prepared according to the method in Example 1, and the difference lies in that:

[0103] In (4), the powder of (Yb 0.25 Lu 0.25 Sc 0.25 Er 0.25 )2SiO5 with the same particle size is used instead of (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 in Example 1.

[0104] ​In (8), the environmental barrier layer composition is (Yb 0.25 Lu 0.25 Sc 0.25 Er 0.25 )2SiO5, and the thickness is 200 μm.

[0105] The high-temperature water-oxygen corrosion performance test was conducted on the environmental barrier coating in Example 2, and the results showed that the environmental barrier coating in the present example did not peel off after water-oxygen corrosion for 300 h.

[0106] The high-temperature CMAS corrosion resistance performance test was conducted on the environmental barrier coating in Example 2, and the results showed that the reaction layer depth was less than 45 μm after 50 h, and the CMAS did not penetrate into the coating.

[0107] The thermal cycle performance test was conducted on the environmental barrier coating in Example 2, and the results showed that the thermal shock life of the environmental barrier coating in the present example was greater than 600 cycles.

[0108] The thermal shock performance test was conducted on the environmental barrier coating in Example 2, and the results showed that the thermal shock life of the environmental barrier coating in the present example was greater than 550 cycles.

[0109] Example 3

[0110] A four-layer multi-component composite environmental barrier coating was prepared according to the method in Example 1, with the difference being that:

[0111] In (1), the SiC f / The size of the SiC substrate sample was 40 mm x 20 mm x 6 mm

[0112] In (7), the thickness of the 7Yb2SiO5-3Yb2Si2O7 intermediate layer was 100 μm.

[0113] In (8), the (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 environmental barrier layer had a thickness of 100 μm.

[0114] The high-temperature water-oxygen corrosion performance test was conducted on the environmental barrier coating in Example 3, and the results showed that the environmental barrier coating in the present example did not peel off after water-oxygen corrosion for 300 h.

[0115] The high-temperature CMAS corrosion resistance performance test was conducted on the environmental barrier coating in Example 3, and the results showed that the reaction layer thickness was less than 40 μm after 50 h of corrosion, and the CMAS did not penetrate into the coating.

[0116] The environmental barrier coating in Example 3 was subjected to thermal cycling performance test, and the results showed that the thermal shock resistance life of the environmental barrier coating in the example was greater than 550 cycles.

[0117] The environmental barrier coating in Example 3 was subjected to thermal shock performance test, and the results showed that the thermal shock life of the environmental barrier coating in the example was greater than 600 cycles.

[0118] Comparative Example 1

[0119] Comparative Example 1 has the same process as Example 1, except that:

[0120] In (4), the powder of Si with the same particle size was used instead of the powder of 9HfSiO4-1Si in Example 1;

[0121] In (5), the Si bond coat layer was prepared on the surface of the CMC substrate by atmospheric plasma spraying method, and the thickness was 50 μm.

[0122] The environmental barrier coating prepared in Comparative Example 1 was subjected to high-temperature water-oxygen corrosion performance test, and the water-oxygen corrosion resistance life of the coating was 168 hours

[0123] The environmental barrier coating in Comparative Example 1 was subjected to high-temperature CMAS corrosion resistance performance test, and the results showed that after 50 h of corrosion, the thickness of the reaction layer was less than 40 μm, and the CMAS did not penetrate into the coating.

[0124] The environmental barrier coating in Comparative Example 1 was subjected to thermal cycling performance test, and the results showed that the thermal shock resistance life of the environmental barrier coating in the example was less than 100 cycles.

[0125] The environmental barrier coating in Comparative Example 1 was subjected to thermal shock performance test, and the results showed that the thermal shock life of the environmental barrier coating in the example was less than 250 cycles.

[0126] Comparative Example 2

[0127] Comparative Example 2 has the same process as Example 2, except that:

[0128] In (4), the powder of Yb2SiO5 with the same particle size was used instead of the powder of (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 in Example 2.

[0129] In (8), the Yb2SiO5 environmental barrier layer was prepared on the surface of the 7Yb2SiO5-3Yb2Si2O7 intermediate layer by atmospheric plasma spraying method, and the thickness was 200 μm.

[0130] The environmental barrier coating prepared in Comparative Example 2 was subjected to high-temperature water-oxygen corrosion performance test, and the water-oxygen corrosion resistance of the coating was 215 hours

[0131] The environmental barrier coating in Comparative Example 2 was subjected to high-temperature CMAS corrosion performance test, and the results showed that after 50h of corrosion, the reaction layer thickness was greater than 60μm, and the CMAS penetration depth was greater than 120μm.

[0132] The environmental barrier coating in Comparative Example 2 was subjected to thermal cycle performance test, and the results showed that the thermal shock resistance of the environmental barrier coating in the present comparative example was less than 200 cycles.

[0133] The environmental barrier coating in Comparative Example 2 was subjected to thermal shock performance test, and the results showed that the thermal shock resistance of the environmental barrier coating in the present comparative example was greater than 450 cycles.

[0134] Comparative Example 3

[0135] Comparative Example 3 has the same process as Example 3, except that:

[0136] In (4), the powder of Yb2SiO5 with the same particle size was used instead of the 7Yb2SiO5-3Yb2Si2O7 powder in Example 3;

[0137] In (7), the atmospheric plasma spraying method was used to prepare a Yb2SiO5 intermediate layer on the surface of the 8Mullite-2BSAS transition layer, with a thickness of 100μm.

[0138] The environmental barrier coating prepared in Comparative Example 3 was subjected to high-temperature water-oxygen corrosion performance test, and the water-oxygen corrosion resistance of the coating was 250 hours

[0139] The environmental barrier coating in Comparative Example 3 was subjected to high-temperature CMAS corrosion performance test, and the results showed that after 50h of corrosion, the reaction layer thickness was less than 40μm, and the CMAS penetration depth was about 30μm.

[0140] The environmental barrier coating in Comparative Example 3 was subjected to thermal cycle performance test, and the results showed that the thermal shock resistance of the environmental barrier coating in the present comparative example was less than 300 cycles.

[0141] The environmental barrier coating in Comparative Example 3 was subjected to thermal shock performance test, and the results showed that the thermal shock resistance of the environmental barrier coating in the present comparative example was less than 300 cycles.

[0142] Comparative Example 4

[0143] Comparative Example 4 has the same process as Example 1, except that:

[0144] In (4), the powder of Mullite with the same particle size was used instead of the 8Mullite-2BSAS powder in Example 3;

[0145] In (6), a Mullite transition layer with a thickness of 50 μm is prepared on the surface of the 9HfSiO4-Si bond coat layer by an atmospheric plasma spraying method.

[0146] The environmental barrier coating prepared in Comparative Example 4 is subjected to high-temperature water-oxygen corrosion performance testing, and the water-oxygen corrosion resistance of the coating is 220 hours.

[0147] The environmental barrier coating in Comparative Example 4 is subjected to high-temperature CMAS corrosion performance testing, and the results show that the reaction layer has a thickness of less than 40 μm after 50 h of corrosion, and the CMAS does not penetrate into the coating.

[0148] The environmental barrier coating in Comparative Example 4 is subjected to thermal cycle performance testing, and the results show that the thermal shock resistance of the environmental barrier coating in the present comparative example is less than 350 cycles.

[0149] The environmental barrier coating in Comparative Example 4 is subjected to thermal shock performance testing, and the results show that the thermal shock resistance of the environmental barrier coating in the present comparative example is less than 350 cycles (peeling position is inside the Mullite layer).

[0150] Comparative Example 5

[0151] Comparative Example 5 has the same process as Example 1, except that:

[0152] A 7Yb2SiO5-3Yb2Si2O7 intermediate layer and a (Yb 0.25 Lu 0.25 Y 0.25 Er 0.25 )2SiO5 environmental barrier layer are directly prepared on the surface of the 9HfSiO4-1Si bond coat layer.

[0153] The environmental barrier coating prepared in Comparative Example 5 is subjected to high-temperature water-oxygen corrosion performance testing, and the water-oxygen corrosion resistance of the coating is 250 hours.

[0154] The environmental barrier coating in Comparative Example 5 is subjected to high-temperature CMAS corrosion performance testing, and the results show that the reaction layer has a thickness of less than 40 μm after 50 h of corrosion, and the CMAS does not penetrate into the coating.

[0155] The environmental barrier coating in Comparative Example 5 is subjected to thermal cycle performance testing, and the results show that the thermal shock resistance of the environmental barrier coating in the present comparative example is less than 350 cycles (peeling position is at the interface between the bond coat layer and the intermediate layer).

[0156] The environmental barrier coating in Comparative Example 5 is subjected to thermal shock performance testing, and the results show that the thermal shock resistance of the environmental barrier coating in the present comparative example is less than 350 cycles (peeling position is at the interface between the bond coat layer and the intermediate layer).

[0157] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the protection scope of the present application.

Claims

1. A high-temperature corrosion resistant multi-phase environmental barrier coating, comprising, in sequence, an HfSiO4-Si binder layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer, and (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer; the HfSiO4-Si adhesive layer is in contact with the substrate material; The Mullite-BSAS transition layer comprises mullite and BSAS, wherein the BSAS has the chemical formula shown in Formula I: (1-x)BaO·xSrO·Al2O3·2SiO2, 0≤x≤1 Formula I; the mass ratio of mullite to BSAS is 2:8~8:

2. In the HfSiO4-Si adhesive layer, the mass ratio of Si to HfSiO4 is 1:(2~10). In the Yb2SiO5-Yb2Si2O7 intermediate layer, the mass ratio of Yb2SiO5 to Yb2Si2O7 is 1:1 to 9:1; (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 In the 2SiO5 environmental barrier layer, RE1, RE2 and RE3 are any three different elements selected from Lu, Er, Y, Sc, Ho, Nd, Gd and Tm.

2. The high-temperature corrosion resistant multi-phase environmental barrier coating according to claim 1, characterized in that, The thickness of the HfSiO4-Si adhesive layer is 50~100μm; the thickness of the Mullite-BSAS transition layer is 50~100μm; the thickness of the Yb2SiO5-Yb2Si2O7 intermediate layer is 100~150μm; the thickness of the (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 The thickness of the 2SiO5 environmental barrier layer is 100~200μm.

3. The method for preparing the high-temperature corrosion resistant multi-phase environmental barrier coating as described in claim 1, comprising the following steps: A) Pretreatment of the matrix material; B) Using atmospheric plasma spraying technology, an HfSiO4-Si bonding layer, a Mullite-BSAS transition layer, a Yb2SiO5-Yb2Si2O7 intermediate layer, and a (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 )2SiO5 environmental barrier layer; C) The coating is subjected to vacuum heat treatment to obtain a multi-component multiphase environmental barrier coating that is resistant to high-temperature corrosion.

4. The preparation method according to claim 3, characterized in that, The matrix material is a ceramic matrix composite material; The pretreatment includes sequentially cleaning, sandblasting, and plasma jet heating of the substrate material.

5. The preparation method according to claim 3, characterized in that, In step B), during the preparation of the HfSiO4-Si bonding layer by atmospheric plasma spraying, the particle size of the HfSiO4-Si powder is 40~150μm. During the preparation of the Mullite-BSAS transition layer by atmospheric plasma spraying, the powder particle size of Mullite-BSAS is 20~80μm; During the preparation of the Yb2SiO5-Yb2Si2O7 intermediate layer by atmospheric plasma spraying, the powder particle size of Yb2SiO5-Yb2Si2O7 is 20~100μm; Atmospheric plasma spraying preparation (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 During the process of creating the 2SiO5 environmental barrier layer, (Yb 0.25 RE1 0.25 RE2 0.25 RE3 0.25 The particle size of 2SiO5 powder is 20~150μm.

6. The preparation method according to claim 3, characterized in that, In step C), the vacuum heat treatment temperature is 1200~1300℃, the vacuum heat treatment time is 4~8h, and the vacuum degree is ≥1×10⁻⁶. -3 Pa and <10×10 -3 Pa.

7. The application of the high-temperature corrosion resistant multi-phase environmental barrier coating as described in claim 1 as a thermal protection coating for ceramic matrix composite surfaces in aero engines.

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