CN116589304A - Low-thermal-conductivity/thermal-expansion hafnium oxide-based thermal/environment barrier coating and preparation method thereof - Google Patents
Low-thermal-conductivity/thermal-expansion hafnium oxide-based thermal/environment barrier coating and preparation method thereof Download PDFInfo
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- 230000004888 barrier function Effects 0.000 title claims abstract description 102
- 238000000576 coating method Methods 0.000 title claims abstract description 56
- 239000011248 coating agent Substances 0.000 title claims abstract description 53
- 229910000449 hafnium oxide Inorganic materials 0.000 title claims abstract description 12
- WIHZLLGSGQNAGK-UHFFFAOYSA-N hafnium(4+);oxygen(2-) Chemical compound [O-2].[O-2].[Hf+4] WIHZLLGSGQNAGK-UHFFFAOYSA-N 0.000 title claims abstract description 12
- 238000002360 preparation method Methods 0.000 title abstract description 21
- 230000007613 environmental effect Effects 0.000 claims abstract description 57
- 239000010410 layer Substances 0.000 claims abstract description 52
- 238000000034 method Methods 0.000 claims abstract description 34
- 239000002344 surface layer Substances 0.000 claims abstract description 31
- 239000011153 ceramic matrix composite Substances 0.000 claims abstract description 23
- 239000000463 material Substances 0.000 claims abstract description 15
- 238000007750 plasma spraying Methods 0.000 claims abstract description 15
- 238000010438 heat treatment Methods 0.000 claims abstract description 11
- 239000000758 substrate Substances 0.000 claims abstract description 5
- 239000000843 powder Substances 0.000 claims description 50
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 44
- 238000005507 spraying Methods 0.000 claims description 28
- 229910052739 hydrogen Inorganic materials 0.000 claims description 24
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 22
- 229910052786 argon Inorganic materials 0.000 claims description 22
- 239000001257 hydrogen Substances 0.000 claims description 22
- 239000011159 matrix material Substances 0.000 claims description 22
- 238000005488 sandblasting Methods 0.000 claims description 20
- 239000002245 particle Substances 0.000 claims description 14
- 210000002381 plasma Anatomy 0.000 claims description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 11
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 7
- 239000004576 sand Substances 0.000 claims description 6
- 239000006004 Quartz sand Substances 0.000 claims description 5
- 239000011863 silicon-based powder Substances 0.000 claims description 5
- 229910052779 Neodymium Inorganic materials 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- 230000002035 prolonged effect Effects 0.000 abstract description 2
- 229910052760 oxygen Inorganic materials 0.000 description 11
- 239000007921 spray Substances 0.000 description 11
- 238000005260 corrosion Methods 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 230000007797 corrosion Effects 0.000 description 9
- 239000001301 oxygen Substances 0.000 description 9
- 230000035939 shock Effects 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 239000002131 composite material Substances 0.000 description 5
- 238000005469 granulation Methods 0.000 description 5
- 230000003179 granulation Effects 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000000498 ball milling Methods 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 238000004901 spalling Methods 0.000 description 4
- 239000012720 thermal barrier coating Substances 0.000 description 4
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- 238000005516 engineering process Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000001816 cooling Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 238000012876 topography Methods 0.000 description 2
- 229910010199 LiAl Inorganic materials 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
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- 238000009792 diffusion process Methods 0.000 description 1
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- 238000000227 grinding Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
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- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- -1 rare earth silicate Chemical class 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
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- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
- C04B41/81—Coating or impregnation
- C04B41/89—Coating or impregnation for obtaining at least two superposed coatings having different compositions
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/52—Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
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- Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
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Abstract
The invention relates to a hafnium oxide-based thermal environment barrier coating with low thermal conductivity/thermal expansion and a preparation method thereof. The thermal/environmental barrier coating comprises HfO with the thickness of 50-100 mu m from the substrate outwards 2 -Si bonding layer, yb with thickness of 100-150 μm 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO with thickness of 150-200 mu m 4 、RE 2 O 3 Modified HfO 2 And a thermal barrier surface layer. And sequentially preparing a bonding layer, an environmental barrier layer and a thermal barrier surface layer on the surface of the pretreated ceramic matrix composite material by adopting an atmospheric plasma spraying process, and carrying out vacuum heat treatment on the prepared thermal/environmental barrier coating. The thermal expansion coefficients of the thermal/environmental barrier coating bonding layer, the environmental barrier layer and the thermal barrier surface layer are increased in gradient, and the thermal barrier surface layer has the characteristics of low thermal conductivity and low thermal expansion coefficient, so that the service life of the thermal/environmental barrier coating in the gas environment of the engine can be greatly prolonged.
Description
Technical Field
The invention belongs to the field of thermal barrier/environmental barrier integrated coatings, and particularly relates to a hafnium oxide-based thermal/environmental barrier coating with low thermal conductivity/thermal expansion and a preparation method thereof.
Background
The ceramic matrix composite is an ideal material for high-temperature components of high-performance aeroengines, and the preparation of the thermal/environmental barrier coating on the surface of the ceramic matrix composite is an important way for improving the service reliability and stability of the ceramic matrix composite in a complex high-temperature gas environment. However, in the actual service process, on one hand, through cracks are generated between the thermal barrier surface layer and the EBC and CMC due to thermal mismatch, so that the interface is oxidized and peeled off; on the other hand, the insufficient heat insulation performance of the surface layer material causes the softening and even melting of the Si bonding layer, and causes cracking and failure of the coating. Currently, the inverse association of "low thermal conductivity" with "high coefficient of thermal expansion" of thermal barrier facing materials is a major reason to limit the application of thermal/environmental barrier coatings at higher temperatures.
The students at home and abroad mainly solve the problems by: (1) Adding a buffer layer to form a multilayer gradient thermal/environmental barrier coating structure; (2) designing a multi-component/high-entropy rare earth silicate material. The former can alleviate the thermal mismatch problem between layers to a certain extent, but in the long-term service process of heat, the chemical stability of interfaces between layers is reduced due to element diffusion, so that the coating performance is rapidly degraded. In addition, the preparation process of the method is high in complexity, and the manufacturing cost is remarkably increased. Most of the latter studies are based on bulk materials, and there is also limited study on the typical thermophysical properties of high-entropy EBC coatings. In fact, due to different preparation methods, the coating components and the structure are dispersed, and the comprehensive performance of the high-entropy coating needs to be further researched.
Therefore, the development of the novel thermal/environmental barrier coating with the characteristics of low thermal conductivity and low thermal expansion coefficient and the preparation technology thereof has very important significance for improving the service temperature and stability of the ceramic matrix composite high-temperature component and reducing the overall weight of the aeroengine.
Disclosure of Invention
In view of the above-mentioned circumstances of the prior art, an object of the present invention is to provide a thermal/environmental barrier coating having both low thermal conductivity and low thermal expansion coefficient at a temperature ranging from room temperature to 1500 ℃ and a method for preparing the same, so that the thermal/environmental barrier coating has excellent thermal shock resistance and anti-oxygen corrosion performance in an engine service environment, thereby improving service stability and reliability of ceramic matrix composite high temperature parts.
To achieve the above object, in one aspect, the present invention provides a hafnium oxide-based thermal/environmental barrier coating with low thermal conductivity/thermal expansion, wherein the coating has a three-layer structure, and comprises HfO from inside to outside in sequence 2 Si-bonded layer, yb 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 A thermal barrier facing, wherein the HfO 2 In the-Si bonding layer, hfO 2 The mass ratio of the beta-LiAlSiO to Si is 1:5-5:1, and the beta-LiAlSiO is prepared from the beta-LiAlSiO and Si 4 、RE 2 O 3 Modified HfO 2 In the thermal barrier surface layer, beta-LiAlSiO 4 、RE 2 O 3 And HfO 2 The mass ratio of (2) is 5-30: 5-30: 40-90, and the RE is one or more of Yb, Y, gd, sm and Nd.
The HfO 2 The thickness of the Si bonding layer is 50-100 mu m; the Yb is 2 Si 2 O 7 The thickness of the environmental barrier layer is 100-150 mu m; the beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 The thickness of the thermal barrier surface layer is 150-200 mu m.
Preferably, the HfO 2 In the-Si bonding layer, hfO 2 The mass ratio of the silicon to the Si is 1:5-1:2.
Preferably, the beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 In the thermal barrier surface layer, beta-LiAlSiO 4 、RE 2 O 3 And HfO 2 The mass ratio of (2) is 15-30: 10-20: 50 to 75.
In another aspect, there is provided a method of preparing a low thermal conductivity/thermal expansion hafnium oxide based thermal/environmental barrier coating as described above, the method comprising the steps of:
s1: pretreating a ceramic matrix composite material matrix;
s2: adopting an atmospheric plasma spraying technology to sequentially prepare HfO on the surface of the ceramic matrix composite substrate 2 Si-bonded layer, yb 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 A thermal barrier facing;
s3: and carrying out vacuum heat treatment on the prepared coating.
Wherein: the step S1 specifically includes the following steps:
s101: placing the ceramic matrix composite material matrix into acetone, ultrasonically cleaning for 10-30 min, and then placing into an oven for drying for 10-20 min, wherein the temperature of the oven is 100-120 ℃;
s102: performing sand blasting treatment on the cleaned matrix, wherein sand blasting sand grains are 100-200 meshes of quartz sand, the sand blasting pressure is 1-3 bar, and the sand blasting time is 10-30 s;
s103: the surface temperature of the composite material matrix is heated to 500-800 ℃ by plasma flame flow.
Preferably, in preparing the HfO 2 In the process of the Si bonding layer, argon and hydrogen are used as plasmas, the flow of the argon is 40-60L/min, the flow of the hydrogen is 6-15L/min, the spraying distance is 60-120 mm, the spraying current is 300-600A, the powder feeding rate is 5-25%, and the HfO is adopted 2 The particle size of the Si powder is 15-80. Mu.m.
Preferably, in the preparation of said Yb 2 Si 2 O 7 In the process of the environmental barrier layer, argon and hydrogen are used as plasmas, the flow rate of the argon is 40-60L/min, the flow rate of the hydrogen is 6-15L/min, the spraying distance is 100-150 mm, the spraying current is 500-1000A, the powder feeding rate is 5-25%, and Yb 2 Si 2 O 7 The particle size of the powder is 15-80 mu m.
Preferably, in preparing the beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 In the process of the thermal barrier surface layer, argon and hydrogen are used as plasmas, the flow rate of the argon is 40-60L/min, the flow rate of the hydrogen is 6-15L/min, the spraying distance is 100-150 mm, the spraying current is 500-1000A, the powder feeding rate is 5-25%, and the beta-LiAlSiO is used for preparing the thermal barrier surface layer 4 、RE 2 O 3 Modified HfO 2 The particle size of the powder is 15-50 mu m.
Preferably, the vacuum heat treatment parameters are: the heat treatment temperature is 1000-1200 ℃, the time is 4-6 h, and the vacuum degree is 10 -3 Pa, i.e. as long as the vacuum degree reaches 10 -3 Pa grade.
The hafnium oxide-based thermal/environmental barrier coating prepared by the invention has a thermal shock life of not less than 500 times under the conditions of 1500 ℃ heat preservation for 5 minutes and air cooling for 5 minutes; at 1500 ℃ and 90% H 2 O-10％O 2 Under 1atm conditions, the coating lifetime is not less than 200 hours.
Drawings
The drawings of the present invention are provided for illustrative purposes only and the proportions and dimensions of the various layers in the drawings are not necessarily consistent with the actual product.
FIG. 1 is a schematic cross-sectional view of a thermal/environmental barrier coating prepared on the surface of a ceramic matrix composite in accordance with an embodiment of the invention;
FIG. 2 is a flow chart of a method of preparing a thermal/environmental barrier coating on a ceramic matrix composite surface in accordance with an embodiment of the invention;
fig. 3 is HfO in an embodiment of the invention 2 -cross-sectional morphology of Si tie layer;
FIG. 4 is a surface topography of a thermal/environmental barrier coating prepared on the surface of a ceramic matrix composite in accordance with an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without making any inventive effort are intended to fall within the scope of the present invention.
Features of various aspects of embodiments of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. The following description of the embodiments is merely for a better understanding of the invention by showing examples of the invention. The present invention is not limited to any particular arrangement and method provided below, but covers any modifications, substitutions, etc. of all product constructions, methods, and the like covered without departing from the spirit of the invention. Well-known structures and techniques have not been shown in detail in the various drawings and the following description in order not to unnecessarily obscure the present invention.
FIG. 1 is a schematic cross-sectional view of a thermal/environmental barrier coating made on the surface of a ceramic matrix composite of the present invention. The thermal/environmental barrier coating comprises HfO from the ceramic matrix composite 1 outwards 2 Si bond coat 2, yb 2 Si 2 O 7 Environmental barrier layer 3, beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 And a thermal barrier coating 4.
In HfO 2 In the-Si bonding layer, hfO 2 The mass ratio of Si to Si is 1:5-5:1, preferably 1:5-1:2. In addition, beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 In the thermal barrier surface layer, RE is one or more of Yb, Y, gd, sm and Nd, and beta-LiAlSiO 4 、RE 2 O 3 And HfO 2 The mass ratio of (2) is 5-30: 5-30: 40 to 90, preferably 15 to 30: 10-20: 50 to 75. The inventors found that β -LiAlSiO 4 、RE 2 O 3 And HfO 2 When the components are matched for use, the obtained thermal barrier surface layer has low thermal conductivity, low thermal expansion coefficient and good high-temperature stability.
FIG. 2 is a flow chart of a method of preparing a thermal/environmental barrier coating on a ceramic matrix composite surface in accordance with one embodiment of the invention.
The method comprises the following steps:
s1: pretreating a ceramic matrix composite material matrix;
s101, placing a ceramic matrix composite material matrix into acetone, ultrasonically cleaning for 10-30 min, and then placing into an oven for drying for 10-20 min, wherein the temperature of the oven is 100-120 ℃;
s102, carrying out sand blasting treatment on the cleaned matrix, wherein sand blasting sand is 100-200 meshes of quartz sand, the sand blasting pressure is 1-3 bar, and the sand blasting time is 10-30S;
s103, heating the composite material matrix by plasma flame flow to enable the surface temperature to reach 500-800 ℃.
S2: adopting an atmospheric plasma spraying technology to sequentially prepare HfO on the surface of the substrate 2 Si-bonded layer, yb 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 A thermal barrier facing;
S201、HfO 2 the particle size of the powder of Si is 15-80 mu m, argon and hydrogen are taken as plasmas, the flow of the argon is 40-60L/min, the flow of the hydrogen is 6-15L/min, the spraying distance is 60-120 mm, the spraying current is 300-600A, and the powder feeding rate is 5-25%.
S202、Yb 2 Si 2 O 7 The particle size of the powder is 15-80 mu m, argon and hydrogen are used as plasmas, the flow of the argon is 40-60L/min, the flow of the hydrogen is 6-15L/min, the spraying distance is 100-150 mm, the spraying current is 500-1000A, and the powder feeding rate is 5-25%.
S203、β-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 The powder particle size is 15-50 μm, argon and hydrogen are used as plasmas, the flow of the argon is 40-60L/min, the flow of the hydrogen is 6-15L/min, the spraying distance is 100-150 mm, the spraying current is 500-1000A, and the powder feeding rate is 5-25%.
S3: vacuum heat treatment is carried out on the prepared thermal/environment barrier coating.
The heat treatment temperature is 1000-1200 ℃, the time is 4-6 h, and the vacuum degree is 10 -3 Pa。
Example 1
(1) Preparation of SiC f SiC ceramic composite matrix test piece with the size of 20mm multiplied by 10mm multiplied by 3mm is cleaned by acetone ultrasonic waves for 20min, then is put into an oven for drying for 20min, and the temperature of the oven is 110 ℃.
(2) For SiC f And (3) carrying out sand blasting treatment before spraying on the SiC matrix, wherein sand blasting sand grains are 150-mesh quartz sand, the sand blasting pressure is 2bar, and the sand blasting time is 20s.
(3) SiC is subjected to f The SiC matrix is arranged on an automatic working operation table of the atmospheric plasma spraying equipment, and is heated by adopting plasma flame flow, so that the surface temperature of the SiC matrix reaches 700 ℃.
(4) Selecting HfO after spray granulation 2 The grain size of the powder of Si is 15-80 mu m, yb 2 Si 2 O 7 The grain size of the powder is 15-80 mu m, and the beta-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 The particle size of the powder is 15-50 mu m. The appearance of the granulated powder is porous spherical powder. And sequentially adding the three powders into a powder feeder of the atmospheric plasma spraying equipment.
Wherein HfO used in the present invention 2 -Si、Yb 2 Si 2 O 7 、β-LiAlSiO 4 、RE 2 O 3 And HfO 2 Powders are available on the market and their preparation processes are also known to the person skilled in the art. For example, hfO in the present embodiment 2 Si powder and Yb 2 Si 2 O 7 The powder was purchased from Hunan Mega thermal spray Material Co., ltd., hfO 2 HfO in Si powder 2 And Si in a mass ratio of 1:4. beta-LiAlSiO 4 Powders were purchased from the long sand college. In addition, although for clarity, the following illustrates beta-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 The preparation of the powder is, however, also known to the person skilled in the art, so that the desired beta-LiAlSiO is prepared from the starting powder by a similar preparation 4 、Y 2 O 3 Modified HfO 2 Powders are within the ability of those skilled in the art.
β-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 The preparation method of the powder comprises the following steps:
(a) Y is set to 2 O 3 And HfO 2 Mixing according to the molar ratio of 0.2:0.8, then carrying out wet ball milling mixing, and carrying out ball milling6 hours, the rotating speed is 300 r.min -1 And (3) placing the ball-milled slurry in a drying box at 80 ℃ for drying for 5 hours, manually grinding, and sieving with a 200-mesh sieve. Sintering the obtained powder for 5 hours at 1500 ℃;
(b) beta-LiAlSiO 4 Powder and Y 2 O 3 -HfO 2 Mixing the powder according to the weight ratio of 1:4, and then carrying out wet ball milling mixing, wherein the ball milling time is 4 hours, and the ball milling rotating speed is 200 r.min -1 Placing the ball-milled slurry in a drying box at 80 ℃ for drying for 5 hours;
(c) Spray granulating the dried powder, wherein the specific parameters are as follows: the inlet temperature is 200 ℃, the outlet temperature is 100 ℃, and the binder is PVA; the spray granulated powder was sintered at 1200 ℃ for 4 hours to remove the organic tie layer.
(5) SiC is sprayed by adopting an atmospheric plasma spraying method f Preparation of HfO on SiC substrate surface 2 -Si bonding layer, adjusting the process parameters as: the flow of argon is 40L/min, the flow of hydrogen is 8L/min, the spraying distance is 80mm, the spraying current is 350A, the powder feeding rate is 25%, and the adhesive layer with the thickness of 50 μm is obtained, and the cross section morphology is shown in figure 3.
(6) Adopting an atmospheric plasma spraying method to spray on HfO 2 Preparation of Yb on the surface of the-Si bond layer 2 Si 2 O 7 The environmental barrier layer, the adjustment technological parameter is: the flow rate of argon is 50L/min, the flow rate of hydrogen is 10L/min, the spraying distance is 120mm, the spraying current is 550A, the powder feeding rate is 5-25%, and Yb with the thickness of 100 mu m is obtained 2 Si 2 O 7 An environmental barrier layer.
(7) Yb-Yb by adopting an atmospheric plasma spraying method 2 Si 2 O 7 Preparation of beta-LiAlSiO on the surface of environmental barrier layer 4 、Y 2 O 3 Modified HfO 2 The thermal barrier surface layer is adjusted by the following technological parameters: the flow of argon is 50L/min, the flow of hydrogen is 8L/min, the spraying distance is 120mm, the spraying current is 600A, and the powder feeding rate is 25%. To obtain beta-LiAlSiO with the thickness of 200 mu m 4 、Y 2 O 3 Modified HfO 2 And a thermal barrier surface layer.
(8) Carrying out vacuum heat treatment on the prepared coating, and adjusting the process parameters as follows: at 1150 DEG CThe time is 6 hours, and the vacuum degree is 5 multiplied by 10 -3 Pa。
The thermal/environmental barrier coating surface topography of example 1 is shown in fig. 4, which was subjected to thermal shock resistance testing:
the thermal shock resistance test mode comprises the following steps: thermal shock resistance was tested at 1500 c for 5 minutes with air cooling for 5 minutes until significant spalling of the coating occurred (spalling area greater than 10%) and was defined as failure. The results show that the thermal shock life of the thermal/environmental barrier coating in this example is 506 cycles.
Example 2
Example 2 is essentially the same as example 1 with the exception that:
in (4), hfO 2 HfO in Si powder 2 And Si in a mass ratio of 1:3, beta-LiAlSiO 4 、Y 2 O 3 /Yb 2 O 3 Modified HfO 2 beta-LiAlSiO in powder 4 And Y 2 O 3 /Yb 2 O 3 Modified HfO 2 The mass ratio of (2) is 15:85.
In (6), yb 2 Si 2 O 7 The thickness of the environmental barrier layer was 150 μm.
In (8), the heat treatment temperature was 1200℃and the time was 4 hours.
The thermal/environmental barrier coating of example 2 was tested for high temperature water oxygen corrosion performance:
the anti-oxidation-corrosion examination mode comprises the following steps: at 1500 ℃ and 90% H 2 O-10％O 2 Corrosion resistance tests were performed under 1atm conditions until significant spalling of the coating (spalling area greater than 10%) was observed, defined as failure. The results show that the thermal/environmental barrier coating in this example has a water oxygen corrosion resistant lifetime of 208 hours.
Example 3
Furthermore, to illustrate beta-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 beta-LiAlSiO in thermal barrier coating 4 、Y 2 O 3 And HfO 2 The influence of different mass ratios on the heat conduction and thermal expansion behaviors of the thermal barrier surface layer material is shown in SiC f Direct surface of SiC ceramic composite material matrixPreparation of beta-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 The thermal barrier surface layer comprises the following specific steps:
(1) Preparation of SiC f SiC ceramic composite matrix test piece with the size of 20mm multiplied by 10mm multiplied by 3mm is cleaned by acetone ultrasonic waves for 20min, then is put into an oven for drying for 20min, and the temperature of the oven is 110 ℃.
(2) For SiC f And (3) carrying out sand blasting treatment before spraying on the SiC matrix, wherein sand blasting sand grains are 150-mesh quartz sand, the sand blasting pressure is 2bar, and the sand blasting time is 20s.
(3) SiC is subjected to f The SiC matrix is arranged on an automatic working operation table of the atmospheric plasma spraying equipment, and is heated by adopting plasma flame flow, so that the surface temperature of the SiC matrix reaches 600 ℃.
(4) Selecting beta-LiAlSiO after spray granulation 4 、Y 2 O 3 Modified HfO 2 The particle size of the powder is 15-50 mu m. The granulated powder is porous spherical powder, and the powder is placed in a powder feeder of an atmospheric plasma spraying device. Wherein, beta-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 beta-LiAlSiO in powder 4 、Y 2 O 3 And HfO 2 The mass ratio of (3) is 5:5:90, 10:10:80, 15:10:75, 20:15:65, 20:20:60, 30:20:50, 30:30:40 respectively.
(5) SiC is sprayed by adopting an atmospheric plasma spraying method f Preparation of beta-LiAlSiO on the surface of SiC matrix 4 、Y 2 O 3 Modified HfO 2 The thermal barrier surface layer is adjusted by the following technological parameters: the flow of argon is 50L/min, the flow of hydrogen is 8L/min, the spraying distance is 120mm, the spraying current is 600A, and the powder feeding rate is 25%. Obtaining the beta-LiAlSiO with the thickness of 800 mu m 4 、Y 2 O 3 Modified HfO 2 And a thermal barrier surface layer.
Thermal expansion coefficients and thermal conductivities of the thermal barrier coatings were tested and the results are shown in table 1. It can be seen that: beta-LiAlSiO 4 、Y 2 O 3 Modified HfO 2 beta-LiAlSiO in thermal barrier coating 4 、Y 2 O 3 And HfO 2 The mass ratio of (2) is 5-30: 5-30: 40 to 90, preferably 15 to 30:10-20: 50-80. beta-LiAlSiO 4 、Y 2 O 3 And HfO 2 When the components are matched for use, the obtained thermal barrier surface layer has low heat conductivity and low thermal expansion coefficient, and has better high-temperature protection effect.
TABLE 1 different weight ratios of beta-LiAlSiO in example 3 4 、Y 2 O 3 Modified HfO 2 Performance index of coating
Comparative example 1
Comparative example 1 the procedure is essentially the same as example 1, except that:
in (4), Y after spray granulation is selected 2 O 3 Modified HfO 2 The particle size of the powder is 15-50 mu m. Y is Y 2 O 3 Modified HfO 2 Y in the powder 2 O 3 And HfO 2 The mass ratio of (2) is 20:80.
In (7), the atmospheric plasma spraying method is adopted to spray the Yb 2 Si 2 O 7 Preparation of the surface of the environmental barrier layer Y 2 O 3 Modified HfO 2 A thermal barrier surface layer, a thickness of 200 μm of Y 2 O 3 Modified HfO 2 And a thermal barrier surface layer.
The thermal shock resistance of the thermal/environmental barrier coating layer prepared in this comparative example was tested using the same test method as in example 1, with a thermal shock life of 275 cycles.
Comparative example 2
Comparative example 2 is essentially the same as example 1 with the difference that:
in (4), beta-LiAlSiO after spray granulation is selected 4 Modified HfO 2 The particle size of the powder is 15-50 mu m. beta-LiAlSiO 4 Modified HfO 2 beta-LiAl in powderSiO 4 And HfO 2 The mass ratio of (2) is 20:80.
In (7), the atmospheric plasma spraying method is adopted to spray the Yb 2 Si 2 O 7 Preparation of beta-LiAlSiO on the surface of environmental barrier layer 4 Modified HfO 2 A thermal barrier surface layer, a thickness of 200 μm of Y 2 O 3 Modified HfO 2 And a thermal barrier surface layer.
The thermal/environmental barrier coating prepared in this comparative example was tested for resistance to oxygen corrosion by the same test method as in example 2, with a 72 hour resistance to oxygen corrosion lifetime.
Comparative example 3
Comparative example 2 is essentially the same as example 1 with the difference that:
in (4), the powder particle size of Si after spray granulation is selected to be 15 to 80 μm.
In (5), the SiC is sprayed by adopting an atmospheric plasma spraying method f Si bonding layer was prepared on the surface of SiC matrix to obtain bonding layer with a thickness of 75. Mu.m.
The thermal/environmental barrier coating prepared in this comparative example was tested for resistance to oxygen corrosion by the same test method as in example 2, and had a resistance to oxygen corrosion life of 123 hours.
The invention has the following beneficial effects:
(1) The thermal/environmental barrier coating HfO of the invention 2 The Si bonding layer has higher bonding strength with the ceramic matrix composite matrix interface, has excellent strength and fracture toughness, and has good oxidation resistance and creep property in the range of 1350-1400 ℃.
(2) The thermal/environmental barrier coating beta-LiAlSiO of the invention 4 、RE 2 O 3 Modified HfO 2 Thermal barrier facing, RE 2 O 3 Doping introduces oxygen vacancies and causes lattice distortion, which can effectively reduce HfO 2 Thermal conductivity of the material; negative expansion property beta-LiAlSiO 4 Can reduce RE 2 O 3 -HfO 2 Thereby increasing the thermal compatibility of the thermal barrier facing with the environmental barrier and bond coat.
(3) The invention is described inHfO in thermal/environmental barrier coating of (c) 2 Si-bonded layer, yb 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 The thermal expansion coefficient of the thermal barrier surface layer is in gradient increasing trend, so that the thermal cycle stress of the coating in the service process is effectively reduced, and the service life of the thermal/environmental barrier coating is remarkably prolonged.
(4) By controlling beta-LiAlSiO in the coating 4 、RE 2 O 3 And HfO 2 The mass percentage of the thermal barrier layer can realize the precise regulation and control of the thermal conductivity and the thermal expansion coefficient of the thermal barrier surface layer. By the synergistic effect of the three components, the comprehensive optimal high-temperature stability, thermal shock resistance and water and oxygen corrosion resistance are realized.
Claims (10)
1. A low thermal conductivity/thermal expansion hafnium oxide based thermal/environmental barrier coating characterized by: the coating comprises HfO from inside to outside 2 Si-bonded layer, yb 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 A thermal barrier facing, wherein
The HfO 2 In the-Si bonding layer, hfO 2 The mass ratio of the silicon to the Si is 1:5-5:1,
the beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 In the thermal barrier surface layer, beta-LiAlSiO 4 、RE 2 O 3 And HfO 2 The mass ratio of (2) is 5-30: 5-30: 40 to 90, and
the RE is one or more of Yb, Y, gd, sm and Nd.
2. The hafnium oxide-based thermal/environmental barrier coating of claim 1, wherein the HfO 2 The thickness of the Si bonding layer is 50-100 mu m; the Yb is 2 Si 2 O 7 The thickness of the environmental barrier layer is 100-150 mu m; the beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 The thickness of the thermal barrier surface layer is 150-200 mu m.
3. According to claimThe hafnium oxide based thermal/environmental barrier coating of claim 1, wherein the HfO 2 In the-Si bonding layer, hfO 2 The mass ratio of the silicon to the Si is 1:5-1:2.
4. The hafnium oxide based thermal/environmental barrier coating of claim 1 wherein the β -LiAlSiO 4 、RE 2 O 3 Modified HfO 2 In the thermal barrier surface layer, beta-LiAlSiO 4 、RE 2 O 3 And HfO 2 The mass ratio of (2) is 15-30: 10-20: 50 to 75.
5. A method of preparing a hafnium oxide based thermal/environmental barrier coating according to claim 1, comprising the steps of:
s1: pretreating a ceramic matrix composite material matrix;
s2: adopting an atmospheric plasma spraying process to sequentially prepare HfO on the surface of the ceramic matrix composite substrate 2 Si-bonded layer, yb 2 Si 2 O 7 Environmental barrier layer and beta-LiAlSiO 4 、RE 2 O 3 Modified HfO 2 A thermal barrier facing;
s3: and carrying out vacuum heat treatment on the prepared coating.
6. The method of claim 5, wherein said step S1 comprises:
s101: putting the ceramic matrix composite material matrix into acetone, ultrasonically cleaning for 10-30 min, and then drying for 10-20 min at 100-120 ℃;
s102: performing sand blasting treatment on the cleaned ceramic matrix composite material, wherein sand blasting sand is 100-200 meshes of quartz sand, the sand blasting pressure is 1-3 bar, and the sand blasting time is 10-30 s;
s103: the surface temperature of the ceramic matrix composite matrix is heated to 500-800 ℃ by plasma flame flow.
7. The method as recited in claim 5 wherein said HfO is prepared by 2 In the case of Si bonding layer, argon and hydrogen are used as plasmas, and the flow rate of argon is 40About 60L/min, the flow of hydrogen is 6-15L/min, the spraying distance is 60-120 mm, the spraying current is 300-600A, the powder feeding rate is 5-25%, and the HfO 2 The particle size of the Si powder is 15-80. Mu.m.
8. The method of claim 5, wherein in preparing said Yb 2 Si 2 O 7 When the barrier layer is in environment, argon and hydrogen are used as plasmas, the flow rate of the argon is 40-60L/min, the flow rate of the hydrogen is 6-15L/min, the spraying distance is 100-150 mm, the spraying current is 500-1000A, the powder feeding rate is 5-25%, and Yb 2 Si 2 O 7 The particle size of the powder is 15-80 mu m.
9. The process according to claim 5, wherein in preparing said β -LiAlSiO 4 、RE 2 O 3 Modified HfO 2 When the thermal barrier surface layer is formed, argon and hydrogen are used as plasmas, the flow rate of the argon is 40-60L/min, the flow rate of the hydrogen is 6-15L/min, the spraying distance is 100-150 mm, the spraying current is 500-1000A, the powder feeding rate is 5-25%, and the beta-LiAlSiO is used for preparing the thermal barrier surface layer 4 、RE 2 O 3 Modified HfO 2 The particle size of the powder is 15-50 mu m.
10. The method according to claim 5, wherein in the step S3, the heat treatment temperature is 1000 to 1200 ℃, the time is 4 to 6 hours, and the vacuum degree is 10 -3 Of the order of Pa.
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