CN114988895A - Impact-resistant thermal cycle and CMAS corrosion resistant complex phase eutectoid environmental barrier coating and preparation method thereof - Google Patents
Impact-resistant thermal cycle and CMAS corrosion resistant complex phase eutectoid environmental barrier coating and preparation method thereof Download PDFInfo
- Publication number
- CN114988895A CN114988895A CN202210700244.5A CN202210700244A CN114988895A CN 114988895 A CN114988895 A CN 114988895A CN 202210700244 A CN202210700244 A CN 202210700244A CN 114988895 A CN114988895 A CN 114988895A
- Authority
- CN
- China
- Prior art keywords
- eutectoid
- phase
- environmental barrier
- barrier coating
- sio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/66—Monolithic refractories or refractory mortars, including those whether or not containing clay
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/16—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/50—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on rare-earth compounds
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/62222—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products obtaining ceramic coatings
-
- 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
-
- 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
- C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
- C04B41/5025—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials with ceramic materials
- C04B41/5045—Rare-earth oxides
-
- 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
- C04B41/85—Coating or impregnation with inorganic materials
- C04B41/87—Ceramics
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3427—Silicates other than clay, e.g. water glass
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
- C04B2235/54—Particle size related information
- C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
- C04B2235/5436—Particle size related information expressed by the size of the particles or aggregates thereof micrometer sized, i.e. from 1 to 100 micron
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B2235/9607—Thermal properties, e.g. thermal expansion coefficient
-
- 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
- Y02T50/00—Aeronautics or air transport
- Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Coating By Spraying Or Casting (AREA)
Abstract
The invention relates to the field of environmental barrier coatings or thermal barrier/environmental barrier integrated coatings, in particular to a complex phase eutectoid environmental barrier coating resisting impact thermal cycle and CMAS corrosion and a preparation method thereof. The complex phase eutectoid environmental barrier coating consists of Si bonding layer and Yb from the substrate to the outside in sequence 2 Si 2 O 7 ‑Yb 2 SiO 5 Complex phase eutectoid surface layer. The preparation method comprises the following steps: (1) preparing a Si bonding layer on the surface of the silicon carbide substrate material by adopting an atmospheric plasma spraying technology; (2) using pure phase Yb 2 Si 2 O 7 Spraying of paintPreparing Yb on the surface of the Si bonding layer by using spherical feed through an atmospheric plasma spraying technology 2 Si 2 O 7 ‑Yb 2 SiO 5 A complex phase eutectoid surface layer; (3) the substrate with the coating is subjected to heat treatment to realize coating crystallization and has the microstructure characteristic of complex phase eutectoid. The complex phase eutectoid environmental barrier coating has excellent impact thermal cycle life and good CMAS corrosion resistance, and can greatly improve the service reliability and stability of the environmental barrier coating in the engine gas environment.
Description
Technical Field
The invention relates to the field of environmental barrier coatings or thermal barrier/environmental barrier integrated coatings, in particular to a complex phase eutectoid environmental barrier coating resisting impact thermal cycle and CMAS corrosion and a preparation method thereof.
Background
The rapid development of aeronautical technologies places increasingly stringent requirements on the efficiency, the weight-to-weight ratio and the emission of pollutants from aircraft engines. From the analysis of the development trend of advanced aircraft engines, the improvement of the turbine front inlet air temperature is the key for improving the efficiency, so that higher requirements are put on the temperature bearing capacity of the thermal structural components of the combustion chamber. SiC f the/SiC ceramic matrix composite has the advantages of high temperature resistance, low density, high specific strength, high toughness and the like, can realize the increase of the gas temperature before the turbine when being applied to the hot end part of the aero-engine, greatly reduces the weight, simplifies the design requirement of a gas cooling structure, and can greatly improve the efficiency of the engine.
High temperature water vapor generated by fuel combustion attacks SiC in the combustion chamber environment of an aircraft engine f the/SiC composite generates volatile silicon hydroxide, which causes dimensional degradation of the composite part. In addition, when the service temperature exceeds 1200 ℃, low melting point oxidation CMAS (CaO-MgO-Al) comes from the environments of runways, atmosphere, volcanic eruption, desert and the like 2 O 3 -SiO 2 ) The fused material is fused and deposited on the surface of a high-temperature structural component of the engine, and reacts with the high-temperature structural component to cause the rapid decline of the performance of the composite material. Therefore, SiC must be used f The surface of the/SiC composite material component is coated with an Environmental Barrier Coating (EBC for short), so that the invasion of the gas environment of the aircraft engine to the high-temperature component is prevented or slowed down, and the long-term and high-reliability service of the aircraft engine in various environments is ensured.
Earlier work showed that rare earth silicates, especially ytterbium disilicate (Yb) 2 Si 2 O 7 ) With ytterbium (Yb) monosilicate 2 SiO 5 ) Has excellent comprehensive performance and is the main system of the prior high-performance environmental barrier coating. Yb of 2 Si 2 O 7 The surface layer of the environmental barrier coating has a thermal expansion coefficient matched with that of the silicon carbide composite material substrate and is matched with Si/SiO 2 The high-temperature-resistant CMAS has relatively insufficient high-temperature-resistant corrosion performance, and needs to be improved to meet the service requirement in an extreme gas environment; yb of 2 SiO 5 Specific Yb 2 Si 2 O 7 Has better steam and CMAS corrosion resistance, but has a thermal expansion coefficient which is higher than that of SiC f the/SiC matrix is large, the thermal stress of the coating is high in the thermal cycle process, and macrocracks are easy to form, so that the coating is prone to premature spalling failure. Thus, Yb 2 Si 2 O 7 And Yb 2 SiO 5 Each has performance characteristics, and the restriction relationship between low stress and long-term corrosion resistance cannot be balanced when the coating is independently applied to an environmental barrier coating surface layer, so that the design requirement facing extreme gas environments above 1400 ℃ cannot be met.
Disclosure of Invention
In order to solve the problems, the invention aims to provide a complex phase eutectoid environmental barrier coating resisting impact thermal cycle and CMAS corrosion and a preparation method thereof, and aims to greatly improve the high-temperature service performance of the rare earth silicate environmental barrier coating. SiO in atmosphere plasma spraying process by using rare earth silicate 2 The characteristic of easy volatilization effect and narrow rare earth silicate phase region is adopted, and single-phase Yb is adopted 2 Si 2 O 7 Spraying spherical feeding, and preparing a high-crystallization-degree complex phase eutectoid environmental barrier coating with excellent phase stability, thermal cycle and CMAS corrosion resistance in situ by controlling a spraying flow and a heat treatment process. The complex phase environmental barrier coating has good application prospect in the field of environmental barrier coatings or thermal barrier/environmental barrier integrated coatings.
The technical scheme of the invention is as follows:
the complex phase eutectoid environmental barrier coating sequentially comprises a Si bonding layer, Yb composed of ytterbium disilicate and ytterbium monosilicate from the outside of a substrate 2 Si 2 O 7 -Yb 2 SiO 5 Composition of heterogeneous eutectoid surface layer, Yb 2 Si 2 O 7 -Yb 2 SiO 5 The ytterbium disilicate phase and the ytterbium monosilicate phase in the heterogeneous eutectoid surface layer are in uniform mutual embedding distribution on the nanometer scale, Yb 2 Si 2 O 7 -Yb 2 SiO 5 The phase composition of the complex phase eutectoid surface layer comprises Yb 2 Si 2 O 7 And Yb 2 SiO 5 ，Yb 2 Si 2 O 7 The content of (A) is 60-90 wt.%.
The impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating, Yb 2 Si 2 O 7 -Yb 2 SiO 5 The crystallization degree of the complex phase eutectoid surface layer is high.
The thickness of the Si bonding layer is 50-150 mu m, and the Yb of the complex phase eutectoid environmental barrier coating resistant to impact thermal cycle and CMAS corrosion 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is 50-300 mu m.
The preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating comprises the following steps:
1) preparing a Si bonding layer on the surface of the silicon carbide substrate material by adopting an atmospheric plasma spraying technology;
2) in a single phase Yb 2 Si 2 O 7 Spraying spherical feed as raw material, and preparing Yb on the surface of Si bonding layer in situ by atmospheric plasma spraying technique 2 Si 2 O 7 -Yb 2 SiO 5 A complex phase eutectoid surface layer;
3) and carrying out heat treatment on the silicon carbide substrate with the sprayed bonding layer and the sprayed surface layer to obtain the high-crystallization-degree complex phase eutectoid environmental barrier coating.
The preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating comprises the steps of 2 Si 2 O 7 The spray ball feed is prepared by the following steps:
According to the preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating, in the step 1, the solid content of the slurry is more than or equal to 40 wt%; the addition amount of the polyvinyl alcohol binder is more than or equal to 0.5 wt.%; the addition amounts of the polyethyleneimine dispersant (PEI) and the polyethylene glycol Plasticizer (PEG) are respectively less than or equal to 2.0 wt.%.
The preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating comprises the steps of cleaning and roughening a silicon carbide substrate material before preparing a Si bonding layer, so that the roughness Ra of the surface to be sprayed reaches 1-8 mu m; further, heating the silicon carbide substrate material by adopting plasma flame flow to ensure that the surface temperature of the silicon carbide substrate material reaches 200-500 ℃.
In the preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating, in the step 1), preparation parameters of the Si bonding layer comprise: argon and hydrogen or argon and helium are used as plasma gas, the flow of the argon is 40-60 slpm, the flow of the hydrogen is 5-15 slpm, the flow of the helium is 5-15 slpm, the spraying distance is 90-200 mm, the arc current is 200-600A, and the powder feeding rate of the spraying feeding is 10-50%.
The preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating comprises the step 2) of Yb 2 Si 2 O 7 -Yb 2 SiO 5 The preparation parameters of the complex phase eutectoid surface layer comprise: the method is characterized in that argon and hydrogen or argon and helium are used as plasma gas, the flow of the argon is 40-90 slpm, the flow of the hydrogen is 5-20 slpm, the flow of the helium is 5-20 slpm, the spraying distance is 90-200 mm, and electric arc electricity is generatedThe flow is 200-600A, and the spraying feeding powder feeding speed is 10-50%.
The preparation method of the complex phase eutectoid environmental barrier coating with shock resistance, thermal cycle resistance and CMAS corrosion resistance comprises the following steps of 3), wherein the thermal treatment eutectoid crystallization temperature is more than or equal to 1000 ℃; the heat treatment time is more than or equal to 1 h; the heat treatment atmosphere was argon.
The design idea of the invention is as follows:
the invention is based on Yb 2 Si 2 O 7 Or Yb 2 SiO 5 When the coating is applied as an environmental barrier coating surface layer, the restriction relationship between low stress and long-term corrosion resistance cannot be balanced in the severe service environment of an aircraft engine, and the bottleneck problem of service requirement in the extreme gas environment above 1400 ℃ cannot be met. SiO in atmosphere plasma spraying process by using rare earth silicate 2 The characteristic of easy volatilization effect and narrow rare earth silicate phase region is adopted, and single-phase Yb is adopted 2 Si 2 O 7 Spraying spherical feed, and preparing a high-crystallization-degree complex phase eutectoid environmental barrier coating with excellent phase stability, thermal shock thermal cycle and CMAS corrosion resistance in situ by controlling a spraying flow and a heat treatment process. Simultaneously improves the thermal shock cycle and the high temperature corrosion resistance of the coating, and is SiC f The thermal structural component made of the/SiC composite material provides long-term effective protection.
The texture characteristics of the coating prepared by the invention have the characteristic of complex phase eutectoid. The complex phase is the component characteristic of the coating, which means that the coating contains Yb 2 Si 2 O 7 And Yb 2 SiO 5 Two phases; eutectoid as a structural feature of the coating, meaning Yb 2 Si 2 O 7 And Yb 2 SiO 5 The distribution of these two phases in the coating is characterized by a typical eutectoid structure, i.e., the two phases exhibit a uniform and intercalated distribution on a nanometer scale (as shown in fig. 2(b), wherein the phase with the darker contrast is ytterbium disilicate and the phase with the lighter contrast is ytterbium monosilicate). The complex phase eutectoid structure is derived from eutectoid reaction generated in the annealing and crystallization process. From Yb 2 O 3 -SiO 2 The binary phase diagram shows that Yb is generated during the spraying process 2 Si 2 O 7 Preferential volatilization of Si-containing components in the powder will result in a coatingThe composition deviates in the direction of less Si, so that an amorphous coating composition of xYb is obtained 2 O 3 ·(1-x)SiO 2 X is more than 0.33 and less than 0.5, i.e. between Yb 2 Si 2 O 7 And Yb 2 SiO 5 In between. From Yb 2 O 3 -SiO 2 The binary phase diagram shows that when the coating is between ytterbium disilicate and ytterbium monosilicate, eutectoid reaction occurs in the amorphous phase in the subsequent heat treatment, namely annealing crystallization process, and crystallization is converted into a complex phase eutectoid structure with ytterbium disilicate and ytterbium monosilicate uniformly distributed in a mutual embedding manner on a nanometer scale, so that the Yb is obtained 2 Si 2 O 7 -Yb 2 SiO 5 And (3) a complex phase eutectoid surface layer. Compared with the method of directly adopting Yb, the in-situ formed complex phase eutectoid tissue 2 Si 2 O 7 Powder of Yb 2 SiO 5 The complex phase mixed structure obtained by mixing and spraying the powder greatly relieves the thermal stress generated by the coating in the thermal cycle process, blocks the permeation of CMAS along the grain boundary, and shows more excellent thermal shock performance and CMAS corrosion resistance.
The invention has the advantages and beneficial effects that:
1. the complex phase eutectoid environmental barrier coating designed by the invention has excellent impact resistance thermal cycle resistance and corrosion resistance. The invention adopts single-phase Yb 2 Si 2 O 7 Spraying spherical feeding, and preparing the high-crystallization-degree complex phase eutectoid environmental barrier coating in situ by controlling a spraying process and a heat treatment process. Compared with directly adopting Yb 2 Si 2 O 7 Powder of Yb 2 SiO 5 The multiphase coating obtained by spraying the mixed powder raw material formed by mixing the powder adopts single-phase Yb 2 Si 2 O 7 The complex phase eutectoid surface layer prepared by the powder feeding in-situ has two homogeneous eutectoid microstructures embedded with each other, so that the thermal stress generated by the coating in the thermal cycle process is greatly relieved, and the impact resistance thermal cycle performance is obviously improved. The concrete expression is as follows: after 200 times of gas thermal shock at room temperature to 1350 ℃, the coating keeps the structural integrity, and has no peeling and cracking phenomena, and no macroscopic vertical crack and delamination crack are found. At the same timeThe complex phase eutectoid microstructure coating shows excellent CMAS corrosion resistance compared with pure phase Yb 2 Si 2 O 7 The CMAS corrosion resistance of the block and the coating without eutectoid structure characteristics is obviously improved. The concrete expression is as follows: using 30mg/cm 2 After the CMAS coating amount is corroded for 50 hours at 1300 ℃, the corrosion depth of the coating is only 70 mu m, and the CMAS coating amount is the best among the known similar rare earth disilicate coatings.
2. The invention designs a complex phase eutectoid environmental barrier coating and SiC f The thermal expansion coefficient of the/SiC matrix is well matched, the coating structure can be obviously simplified, and the method is suitable for large-scale production. Using single phase Yb 2 Si 2 O 7 Powder Yb obtained by controlling the spraying process and the heat treatment eutectoid process 2 Si 2 O 7 -Yb 2 SiO 5 The proportion of two phases in the complex phase eutectoid surface layer is adjustable in a larger range, the thermal expansion coefficient of the coating and the substrate can be effectively matched, the corrosion resistance is improved, and Yb used in the prior complex structure is avoided 2 SiO 5 The surface layer ensures the corrosion resistance and is made of Yb 2 Si 2 O 7 The transition layer is used for relieving the design mode of thermal expansion coefficient mismatch, and the preparation process flow of the advanced environment barrier coating is simplified.
3. By combining the pulping process with the spray granulation process, the spherical agglomerated powder with narrow particle size distribution and particle size of 50-80 microns can be obtained. The invention obtains spherical agglomerated powder with the particle size distribution range of 50-80 mu m by regulating and controlling key parameters in the pulping process and the spray drying process. Research shows that whether the particle size range of the spherical agglomerated powder is in the interval or not plays a key role in obtaining two high-crystallinity complex-phase eutectoid coatings with uniform mutual embedment in the subsequent plasma spraying and heat treatment processes. In the preparation process of the spherical agglomerated powder, the content of the binder and the solid content have great influence on the particle size distribution. Through an iterative optimization test, spherical agglomerated powder with the overall particle size distribution of 50-80 microns can be obtained by adopting higher binder content (1.5-3.0 wt.%) and solid content (40-60 wt.%) and matching with a higher feeding speed.
4. The invention designs a complex phaseThe eutectoid environmental barrier coating has low raw material cost while maintaining excellent thermal shock resistance and corrosion resistance. Preparation of Single phase Yb 2 Si 2 O 7 Yb required for powder feeding 2 O 3 Raw material powders, the price of which is only other rare earth oxides, e.g. Lu 2 O 3 And Sc 2 O 3 About 1/10, but the obtained environmental barrier coating has more excellent performance and is more suitable for harsh service environment as described above.
Drawings
FIG. 1 shows a single-phase Yb produced in example 1 according to the invention 2 Si 2 O 7 The spray-coated spherical feedstock (a) has an X-ray diffraction pattern in which the inset is a scanning electron microscopic image of the agglomerated spherical powder and (b) has a laser particle size distribution. (a) In the figure, the abscissa 2 θ represents the diffraction angle (degrees), and the ordinate Intensity represents the relative Intensity (arb. units). (b) In the figure, the abscissa Particle Size represents the Particle Size (. mu.m), and the ordinate Volume represents the relative Volume percentage (%).
Fig. 2 shows (a) an X-ray diffraction pattern and (b) a high power cross-sectional morphology of the complex phase eutectoid environmental barrier coating prepared in example 2 of the present invention. (a) In the figure, the abscissa 2 θ represents the diffraction angle (degrees), and the ordinate Intensity represents the relative Intensity (arb. units).
Fig. 3 shows (a) an X-ray diffraction pattern and (b) a high power cross-sectional morphology of the complex phase eutectoid environmental barrier coating prepared in example 3 of the present invention. (a) In the figure, the abscissa 2 θ represents the diffraction angle (degrees), and the ordinate Intensity represents the relative Intensity (arb. units).
Fig. 4 shows (a) a surface scanning electron microscopic morphology and (b) a cross-sectional morphology of the complex phase eutectoid environmental barrier coating prepared in example 4 of the present invention after 200 times of thermal shock at room temperature to 1350 ℃.
FIG. 5 shows the cross-sectional shapes of the complex phase eutectoid environmental barrier coating prepared in example 5 of the present invention after CMAS corrosion for (a)4h and (b)50h at 1300 ℃.
FIG. 6 shows the X-ray diffraction pattern and the high-power cross-sectional morphology of the complex phase eutectoid environmental barrier coating prepared in comparative example 1 of the present invention. (a) In the figure, the abscissa 2 θ represents the diffraction angle (degrees), and the ordinate Intensity represents the relative Intensity (arb. units).
FIG. 7 shows the X-ray diffraction pattern and the high-power cross-sectional morphology of the complex-phase eutectoid environmental barrier coating prepared in comparative example 2 of the present invention. (a) In the figure, the abscissa 2 θ represents the diffraction angle (degrees), and the ordinate Intensity represents the relative Intensity (arb. units).
FIG. 8 is a cross-sectional view of the complex phase eutectoid environmental barrier coating prepared by comparative example 3 of the present invention after CMAS corrosion for (a)4h and (b)50h at 1300 ℃.
Detailed Description
In the concrete implementation process, the core technical route of the invention is realized by Yb 2 Si 2 O 7 The Si component is more volatile in the atmospheric plasma spraying process, and Yb is controlled in a certain range by regulating and controlling the spraying process parameters 2 Si 2 O 7 And Yb 2 SiO 5 The ratio of two phases, preferably the heat treatment process of coating crystallization, obtains two-phase homogeneous and mutually embedded complex phase eutectoid coating, simultaneously improves the thermal shock cycle and high temperature corrosion resistance of the coating, and is SiC f The thermal structural component of the/SiC composite material provides an efficient protective coating.
In order to achieve the above object, in one aspect, the present invention provides a complex phase eutectoid environmental barrier coating formed on a silicon carbide substrate material, the complex phase eutectoid environmental barrier coating comprising, in order from the substrate outward, a Si bonding layer and Yb composed of ytterbium disilicate and ytterbium monosilicate 2 Si 2 O 7 -Yb 2 SiO 5 Complex phase eutectoid surface layer.
In the complex phase eutectoid environmental barrier coating, Yb 2 Si 2 O 7 -Yb 2 SiO 5 The bi-silicate ytterbium phase and the mono-silicate ytterbium phase in the complex phase eutectoid surface layer present the characteristic of uniform mutual embedded distribution on the nanometer scale.
Yb of the above 2 Si 2 O 7 -Yb 2 SiO 5 The phase composition of the complex phase eutectoid surface layer comprises Yb 2 Si 2 O 7 And Yb 2 SiO 5 ，Yb 2 Si 2 O 7 The content of (b) is 60-90 wt.%, preferably 70-90 wt.%. Yb of 2 Si 2 O 7 -Yb 2 SiO 5 The crystallization degree of the complex phase eutectoid surface layer is high, and the meaning of the high crystallization degree is as follows: yb of 2 Si 2 O 7 -Yb 2 SiO 5 The proportion of the crystalline phase in the complex phase eutectoid surface layer is high. As shown in fig. 2(a), the X-ray diffraction peak of the coating is sharp, and no amorphous characteristic broadening peak appears, indicating that the prepared coating has high crystallization degree.
The thickness of the Si bonding layer is 50-150 mu m, preferably 50-100 mu m; yb of the above 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is 50-300 μm, preferably 100-200 μm.
On the other hand, the invention provides a preparation method of an impact-resistant thermal cycle and corrosion-resistant complex phase eutectoid environmental barrier coating, which mainly comprises the following steps:
first, using single-phase Yb 2 Si 2 O 7 Agglomerating the powder by a spray drying method and calcining the powder in a muffle furnace to remove the photoresist to obtain single-phase Yb with the particle size distribution range of 50-80 mu m 2 Si 2 O 7 Spherical agglomeration granulation powder.
In which Yb is single phase 2 Si 2 O 7 The powder is prepared by adopting a two-step method: firstly, mixing ytterbium oxide and silicon dioxide according to a molar ratio of Yb to Si to O of 2 to 7, performing ball milling and mixing for 8-24 hours in a silicon nitride ball milling tank by taking absolute ethyl alcohol as a medium to form fully mixed slurry, drying in an oven at 80 ℃, and sieving to obtain powder; then pouring the mixture into a zirconia crucible to perform solid-phase reaction in a muffle furnace, wherein the heating rate is 5-15 ℃/min, the sintering temperature is 1400-1600 ℃, and the sintering time is 0.5-4.0 hours to obtain pure-phase Yb 2 Si 2 O 7 And (3) powder. Secondly, the spherical agglomeration granulation powder is obtained by combining a pulping process and a spray drying method: pure phase Yb 2 Si 2 O 7 Uniformly mixing the powder, deionized water, a polyvinyl alcohol binder (PVA), a polyethyleneimine dispersant (PEI) and a polyethylene glycol Plasticizer (PEG) to obtain the slurry. In the process of preparing the slurry, the solid content of the slurry is required to be more than or equal to 40wt, preferably 40-60 wt.%, and spherical agglomerated powder cannot be obtained at lower or higher solid content; the addition amount of the PVA binder is not less than 0.5 wt.%, preferably 1.5-3.0 wt.%, and the binder in the addition amount within the range can be fully coated on the surfaces of original powder particles, the particles are mutually communicated and connected through a three-dimensional resin framework, and spherical agglomerated powder with the particle size distribution range of 50-80 μm is obtained through a subsequent spray drying process. The addition amounts of the PEI dispersant and the PEG plasticizer are respectively less than or equal to 2.0 wt%, preferably 0.5-2.0 wt%, and the functions of the PEI dispersant and the PEG plasticizer are to uniformly disperse powder and adjust the viscosity of slurry. Then, transferring the slurry to a spray drying granulation tower for agglomeration treatment to obtain spherical agglomerated granulation powder; the obtained spherical agglomeration granulation powder is calcined and degummed at the high temperature of 1300 ℃ in a muffle furnace to obtain single-phase Yb with the particle size distribution of 50-80 mu m 2 Si 2 O 7 Spraying spherical feeding.
And secondly, preparing a Si bonding layer on the surface of the silicon carbide substrate material by adopting an atmospheric plasma spraying technology, wherein the thickness of the Si bonding layer is more than or equal to 50 micrometers, and preferably 50-100 micrometers. The bonding layer plays a role in improving the bonding force between the surface layer and the substrate.
In the spraying process, argon and hydrogen (or argon and helium) are used as plasma gas, the flow of the argon is 40-60 slpm, the flow of the hydrogen is 5-15 slpm, the flow of the helium is 5-15 slpm, the spraying distance is 90-200 mm, the arc current is 200-600A, the powder feeding rate of spraying feeding is 10-50%, and the powder feeding rate has the meaning expressed by percentage: the rotating speed of the powder feeder turntable accounts for the percentage of the maximum rotating speed.
Before the Si bonding layer is prepared, the silicon carbide substrate material is cleaned and roughened, so that the roughness Ra of the surface to be sprayed reaches 1-8 mu m, preferably 2-5 mu m. Further, heating the silicon carbide substrate material by adopting plasma flame flow to ensure that the surface temperature of the silicon carbide substrate material reaches 200-500 ℃.
In a third step, the single-phase Yb obtained in the first step is used 2 Si 2 O 7 Spraying spherical feed, and preparing Yb in situ on the surface of the Si bonding layer by using an atmospheric plasma spraying technology 2 Si 2 O 7 -Yb 2 SiO 5 And (3) a complex phase eutectoid surface layer.
The third step is to obtain Yb composed of ytterbium disilicate and ytterbium monosilicate 2 Si 2 O 7 -Yb 2 SiO 5 The key step of the complex phase eutectoid surface layer. The agglomerated powder may be heated to 2000-3500 ℃ during atmospheric plasma spraying. In this temperature range, SiO 2 Saturated vapor pressure ratio Yb of 2 O 3 The saturated vapor pressure of the pressure is 5 to 10 orders of magnitude higher. Therefore, Yb in this process 2 Si 2 O 7 SiO in (2) 2 The components are more obviously volatilized, so that the obtained amorphous coating component is between Yb and Yb 2 Si 2 O 7 And Yb 2 SiO 5 I.e. xYb 2 O 3 ·(1-x)SiO 2 X is more than 0.33 and less than 0.5. From Yb 2 O 3 -SiO 2 The binary phase diagram shows that when the coating is between ytterbium disilicate and ytterbium monosilicate, eutectoid reaction occurs in the amorphous phase in the annealing crystallization process of subsequent heat treatment, and the crystallization is converted into a complex-phase eutectoid structure with ytterbium disilicate and ytterbium monosilicate uniformly distributed in an embedded manner on a nanometer scale, so that the Yb is obtained 2 Si 2 O 7 -Yb 2 SiO 5 And (3) a complex phase eutectoid surface layer. In this step, single-phase Yb 2 Si 2 O 7 When the particle size range of the spraying spherical feed is set to be 50-80 mu m, the performance of the prepared complex phase eutectoid environmental barrier coating is optimal. The spray feed with the particle size range of less than 50 mu m is easy to generate the over-melting phenomenon in the spraying process, so that SiO 2 The components are volatilized too much, and the prepared coating contains more Yb 2 SiO 5 A phase region, wherein two eutectoid tissues embedded uniformly with each other cannot be obtained through a subsequent heat treatment crystallization step; while the melting degree of the spraying feed with the particle size range of more than 80 mu m is slightly lower in the spraying process, SiO is 2 The components have small volatilization, and the prepared coating contains more Yb 2 Si 2 O 7 In the phase region, two eutectoid tissues embedded uniformly with each other cannot be obtained.
In the spraying process, argon and hydrogen (or argon and helium) are used as plasma gas, the flow of the argon is 40-90 slpm, the flow of the hydrogen is 5-20 slpm, the flow of the helium is 5-20 slpm, the spraying distance is 90-200 mm, the arc current is 200-600A, the powder feeding rate of spraying feeding is 10-50%, and the powder feeding rate has the meaning expressed by percentage: the rotating speed of the powder feeder turntable accounts for the percentage of the maximum rotating speed.
And fourthly, placing the silicon carbide substrate with the sprayed bonding layer and the surface layer in an argon protective atmosphere for heat treatment to obtain the complex phase eutectoid environmental barrier coating with high crystallization degree.
The coating prepared in the third step has high amorphous phase content and poor high-temperature stability, cannot exert the advantages of thermal shock resistance and corrosion resistance of a complex phase surface layer, and needs to be subjected to annealing crystallization treatment. From Yb 2 O 3 -SiO 2 The binary phase diagram shows that Yb is in the coating 2 Si 2 O 7 And Yb 2 SiO 5 Eutectoid reaction occurs in the crystallization annealing process, and two heterogeneous eutectoid coatings which are embedded uniformly on a nanometer scale are formed. In the heat treatment eutectoid crystallization process, the heat treatment temperature is more than or equal to 1000 ℃, and 1100-1400 ℃ is preferred; the heat treatment time is more than or equal to 1h, preferably 5-30 h; the heat treatment atmosphere was argon.
From the first step to the fourth step, a single phase Yb can be formed 2 Si 2 O 7 In-situ preparation of Yb from powder 2 Si 2 O 7 -Yb 2 SiO 5 Complex phase eutectoid surface layer. Compared with directly adopting Yb 2 Si 2 O 7 Powder of Yb 2 SiO 5 The mixed powder obtained by mixing the powder is sprayed to obtain a multiphase coating, and the multiphase coating is formed by adopting single-phase Yb 2 Si 2 O 7 The complex phase eutectoid surface layer prepared by the powder in situ has two eutectoid tissues which are embedded uniformly, so that the thermal stress generated by the coating in the thermal cycle process is greatly relieved, and the impact thermal cycle performance is obviously improved. The method comprises the following specific steps: after 200 times of gas thermal shock at 1350 ℃, the coating keeps complete structure, has no peeling and cracking phenomena, and has no vertical crack and delamination crack. But directly adopts Yb 2 Si 2 O 7 Powder of Yb 2 SiO 5 Complex phase coating obtained by spraying mixed powder formed by mixing powderThe layer, after only 40 thermal cycles, suffered peel failure. Meanwhile, the complex phase eutectoid structure coating shows excellent CMAS corrosion resistance compared with pure phase Yb 2 Si 2 O 7 The CMAS corrosion resistance of the block and the coating without eutectoid structure characteristics is obviously improved, and the CMAS corrosion resistance is optimal in the known similar rare earth disilicate coatings. The method specifically comprises the following steps: using 30mg/cm 2 The coating amount of the CMAS is only 70 mu m after being corroded at 1300 ℃ for 50 h. Compared with single-phase Yb prepared by adopting PS-PVD technology 2 Si 2 O 7 The coating, which was etched at 1300 ℃ for 10h with the same CMAS coating amount, was completely etched through by CMAS to a thickness of about 100 μm.
Using single phase Yb 2 Si 2 O 7 Spray powder in-situ preparation to obtain Yb 2 Si 2 O 7 -Yb 2 SiO 5 Complex phase eutectoid surface layer and SiC f The thermal expansion coefficient of the/SiC matrix is well matched, the coating structure can be obviously simplified, and the method is suitable for large-scale production. In addition, the complex phase eutectoid environmental barrier coating designed by the invention has lower raw material cost while maintaining excellent thermal shock resistance and corrosion resistance. Preparation of Single phase Yb 2 Si 2 O 7 Yb required for powder feeding 2 O 3 Raw material powders, the price of which is only other rare earth oxides, e.g. Lu 2 O 3 And Sc 2 O 3 About 1/10, but the obtained environmental barrier coating has the characteristics of excellent performance and low cost.
The invention is further explained below with reference to the figures and examples, which are not intended to be limiting.
Among the main reagents mentioned in the following examples, polyethylene glycol is preferably analytically pure AR, and polyvinyl alcohol is preferably super grade pure GR, and there is no particular limitation on the reagent production companies, and commercially available powder products well known in the art are available; of the apparatuses mentioned in the examples, the planetary ball mill and the spray drying tower are not limited to specific types, and those well known in the art may be selected.
Example 1
In the present embodiment, the first and second electrodes are,single phase Yb 2 Si 2 O 7 The preparation method of the spraying feed powder comprises the following specific steps:
(1) pure phase Yb 2 Si 2 O 7 Uniformly mixing powder, deionized water, a polyvinyl alcohol binder (PVA), a polyethyleneimine dispersant (PEI) and a polyethylene glycol Plasticizer (PEG) to obtain slurry;
wherein, mixing adopts a planetary ball mill, and the ball milling parameters are as follows: the mass ratio of the ball material is 2:1, the rotating speed is 200rpm, and the mass ratio of the ball material to the ball material is 1:1:1, wherein the ball milling medium is silicon nitride balls with the particle diameters of 10mm, 8mm and 5 mm.
The solid content of the slurry is 45 wt%, the adding amount of the binder is 1.5 wt%, and the adding amounts of the dispersant and the plasticizer are 1.5 wt% respectively;
(2) transferring the slurry to a spray drying granulation tower for agglomeration treatment to obtain spherical agglomerated granulation powder; calcining the obtained spherical agglomerated and granulated powder in a muffle furnace at 1300 ℃ to remove the glue to obtain single-phase Yb with the particle size distribution of 50-80 mu m 2 Si 2 O 7 Spraying spherical feeding.
Wherein the parameters of the agglomeration treatment are as follows:
the inlet temperature of the spray drying tower is 300 ℃, the outlet temperature is 150 ℃, the rotation speed of the peristaltic pump is 25rpm, the atomization pressure is 0.10MPa, and the air inlet volume is 3.0m 3 /min。
The agglomerated spherical powder was tested and the results were as follows:
as shown in FIG. 1(a), single-phase Yb 2 Si 2 O 7 X-ray diffraction pattern of spray-coated spherical feedstock, wherein the inset is a scanning electron microscopic image of agglomerated spherical powder, as can be seen from the figure, Yb 2 Si 2 O 7 The characteristic peaks of the mixture exist and no impurity diffraction peak appears, which indicates that the prepared spraying spherical feed is single-phase Yb 2 Si 2 O 7 . And single phase Yb 2 Si 2 O 7 The spraying feed powder is in a spherical shape with a compact and smooth surface, uniform particle size distribution and better sphericity.
As shown in FIG. 1(b), the laser particle size distribution of the agglomerated spherical powder shows that the particle size distribution is mainly between 50 μm and 80 μm, and the median particle size D50 is about 60 μm.
Through the detection of fluidity, the single-phase Yb 2 Si 2 O 7 The flowability of the sprayed ball feed was 55s/50 g.
The apparent bulk density of the single-phase Yb 2 Si 2 O 7 The apparent density of the sprayed spherical feed is 1.24g/cm 3 。
Example 2
In this embodiment, the impact-resistant thermal cycle and CMAS corrosion-resistant complex phase eutectoid environmental barrier coating sequentially comprises a Si bonding layer and Yb from the substrate to the outside 2 Si 2 O 7 -Yb 2 SiO 5 The preparation method of the complex phase eutectoid surface layer comprises the following steps:
and cleaning and roughening the surface of the selected silicon carbide substrate material to ensure that the roughness Ra of the surface to be sprayed reaches 2-5 mu m. Further, before the Si bonding layer is prepared, the substrate material is heated by plasma flame flow, so that the surface temperature of the substrate material reaches 300-400 ℃, and the bonding force of the coating can be improved by a clean or reactive surface with proper roughness.
Preparing a Si bonding layer on the surface of a substrate by adopting an atmospheric plasma spraying method, wherein the main process parameters are as follows: the flow of main argon is 45slpm, the flow of auxiliary hydrogen is 5slpm, the spraying arc current is 400A, the spraying feeding powder feeding rate is 20%, the spraying distance is 90mm, and the thickness of the prepared Si bonding layer is about 70-90 μm.
Adopts single-phase Yb with the particle size distribution range of 50-80 mu m 2 Si 2 O 7 Spray coating of spherical feedstock (example 1) for the preparation of Yb by atmospheric plasma spraying 2 Si 2 O 7 -Yb 2 SiO 5 The main technological parameters of the complex phase eutectoid surface layer are as follows: the flow rate of main argon is 45slpm, the flow rate of auxiliary hydrogen is 5slpm, the spraying arc current is 200A, the spraying feeding powder-feeding rate is 20%, the spraying distance is 100mm, and the prepared Yb 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is about 140-160 μm.
Spraying Si adhesive layer on the tape andYb 2 Si 2 O 7 -Yb 2 SiO 5 and placing the substrate of the complex phase eutectoid surface layer in an argon protective atmosphere for heat treatment to prepare the highly crystallized complex phase eutectoid environmental barrier coating. The heat treatment temperature is 1200 ℃, and the heat treatment time is 10 hours.
As shown in FIG. 2(a), the X-ray diffraction pattern of the prepared complex phase eutectoid environmental barrier coating is shown in the figure, and the complex phase eutectoid environmental barrier coating is formed by Yb 2 Si 2 O 7 Phase and Yb 2 SiO 5 Phase composition. By Rietveld refinement, the Yb in the coating can be calculated 2 Si 2 O 7 Phase content 80 wt%, Yb 2 SiO 5 The phase content was 20 wt%.
As shown in FIG. 2(b), the high-power cross-sectional morphology of the prepared complex phase eutectoid environmental barrier coating can be seen from the figure, the coating presents two microstructures embedded uniformly, wherein the region with brighter contrast is Yb 2 SiO 5 The region with relatively low contrast is Yb 2 Si 2 O 7 And (4) phase.
Example 3
The present embodiment 3 differs from embodiment 2 in that:
preparing Yb on the surface of a substrate by adopting an atmospheric plasma spraying method 2 Si 2 O 7 -Yb 2 SiO 5 The main technological parameters of the complex phase eutectoid surface layer are as follows: the flow rate of main argon is 45slpm, the flow rate of auxiliary hydrogen is 5slpm, the spraying arc current is 600A, the spraying feeding powder-feeding rate is 20%, the spraying distance is 100mm, and the prepared Yb 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is about 100-110 μm.
Spraying Si bonding layer and Yb onto the tape 2 Si 2 O 7 -Yb 2 SiO 5 And placing the substrate of the complex phase eutectoid surface layer in an argon protective atmosphere for heat treatment to prepare the highly crystallized complex phase eutectoid environmental barrier coating. The heat treatment temperature is 1100 ℃, and the heat treatment time is 20 h.
As shown in FIG. 3(a), the X-ray diffraction pattern of the obtained complex phase eutectoid environmental barrier coating is preparedIt can be seen that the complex phase eutectoid environmental barrier coating consists of Yb 2 Si 2 O 7 Phase and Yb 2 SiO 5 Phase composition. By Rietveld refinement, the Yb in the coating can be calculated 2 Si 2 O 7 Phase content 80 wt%, Yb 2 SiO 5 The phase content was 20 wt%.
As shown in FIG. 3(b), the high-power cross-sectional morphology of the prepared complex-phase eutectoid environmental barrier coating shows that the coating presents two microstructures uniformly embedded with each other, wherein the region with brighter contrast is Yb 2 SiO 5 The region with relatively low contrast is Yb 2 Si 2 O 7 And (4) phase(s).
Example 4
In this embodiment 4, a complex phase eutectoid environmental barrier coating is obtained according to the process of the embodiment 2, and a fuel gas thermal shock performance test is performed on the complex phase eutectoid environmental barrier coating.
The method comprises the following specific steps: the coated sample is fixed on a gas thermal shock testing machine, propane is used as fuel, high-purity oxygen is used as combustion improver, and flame with high flow speed and high temperature is generated to perform thermal shock test on the surface of the coating. The specific test conditions were: heating the surface of the sample by high-temperature gas for 20s to 1350 +/-15 ℃; keeping the temperature for 5min at the temperature; cooling with compressed air at 20s to below 300 deg.C, and cooling for 5 min; the thermal cycling experiment was repeated until the coating was peeled off or the number of thermal cycles reached 200.
As shown in fig. 4(a), the surface of the complex phase eutectoid environmental barrier coating after 200 times of impact thermal cycles scans the electron microscopic morphology, and it can be seen that after 200 times of 1350 ℃ gas impact thermal cycles, the coating maintains the structural integrity and does not peel off or crack.
As shown in fig. 4(b), the cross-sectional morphology of the complex phase eutectoid environmental barrier coating after 200 times of impact thermal cycles shows that after 200 times of 1350 ℃ gas impact thermal cycles, no vertical cracks and delamination cracks are generated in the coating, indicating that the coating has excellent thermal shock resistance.
Example 5
Example 5 Complex phase eutectoid environmental barrier coating obtained by Process of example 2The phase eutectoid environmental barrier coating is used for carrying out a CMAS corrosion resistance test, and the CMAS powder comprises 33CaO-9MgO-13AlO 1.5 -45SiO 2 The material is obtained by ball milling, mixing evenly, then preserving heat for 24 hours in a muffle furnace at 1200 ℃ and carrying out solid phase reaction. According to 30mg/cm 2 Coating the surface of a sample with a coating, then placing the sample in a muffle furnace for heat preservation for 4h and 50h at 1300 ℃, cooling the sample along with the furnace, and taking out the corrosion sample.
As shown in FIG. 5(a), the cross-sectional morphology of the complex phase eutectoid environmental barrier coating after being corroded by CMAS for 4h at 1300 ℃, as can be seen from the figure, the corrosion depth of the coating is 52 μm.
As shown in FIG. 5(b), the cross-sectional morphology of the complex phase eutectoid environmental barrier coating after CMAS corrosion for 50h at 1300 ℃, as can be seen from the figure, the corrosion depth of the coating is 70 μm, which indicates that the prepared coating has excellent high temperature CMAS corrosion resistance.
Comparative example 1
Comparative example 1 differs from example 2 in that:
adopts single-phase Yb with the particle size distribution range of 5-20 mu m 2 Si 2 O 7 Spraying spherical feed to the surface of silicon carbide substrate by atmospheric plasma spraying to prepare Yb 2 Si 2 O 7 -Yb 2 SiO 5 Complex phase eutectoid surface layer, prepared Yb 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is about 100-110 μm.
As shown in FIG. 6(a), the X-ray diffraction pattern of the prepared complex phase eutectoid environmental barrier coating is shown by Yb 2 Si 2 O 7 Phase and Yb 2 SiO 5 Phase composition. By Rietveld refinement, the Yb in the coating can be calculated 2 Si 2 O 7 Phase content 65 wt%, Yb 2 SiO 5 The phase content was 35 wt%.
As shown in FIG. 6(b), the prepared complex phase eutectoid environmental barrier coating has a high-power cross-sectional morphology, wherein the region with relatively high contrast is Yb 2 SiO 5 The region with relatively low contrast is Yb 2 Si 2 O 7 And (4) phase(s). As can be seen, in FIG. 6(b), compared with FIG. 2(b)The heterogeneous eutectoid microstructure is not uniformly distributed, and the coating contains more Yb 2 SiO 5 Phase region.
The comparative example shows that when the particle size distribution range of the spraying feed powder is less than 50-80 μm or the particle size distribution range is less than 50-80 μm, Yb with uniformly distributed complex phase eutectoid structure is difficult to prepare 2 Si 2 O 7 -Yb 2 SiO 5 And (3) a complex phase eutectoid surface layer.
Comparative example 2
Comparative example 2 differs from example 2 in that:
adopts single-phase Yb with the particle size distribution range of 80-110 mu m 2 Si 2 O 7 Spraying spherical feed to the surface of the substrate by atmospheric plasma spraying to prepare Yb 2 Si 2 O 7 -Yb 2 SiO 5 Complex phase eutectoid surface layer, prepared Yb 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is about 100-110 μm.
As shown in FIG. 7(a), the X-ray diffraction pattern of the prepared complex phase eutectoid environmental barrier coating is shown by Yb 2 Si 2 O 7 Phase and Yb 2 SiO 5 Phase composition. By Rietveld refinement, the Yb in the coating can be calculated 2 Si 2 O 7 Phase content 90 wt%, Yb 2 SiO 5 The phase content was 10 wt%.
As shown in FIG. 7(b), the prepared complex phase eutectoid environmental barrier coating has a high-power cross-sectional morphology, wherein the region with relatively high contrast is Yb 2 SiO 5 The region with relatively low contrast is Yb 2 Si 2 O 7 And (4) phase(s). As can be seen from the graph, the complex eutectoid structure in FIG. 7(b) is not uniformly distributed and the coating contains much Yb as compared with FIG. 2(b) 2 Si 2 O 7 Phase region.
The comparative example shows that when the particle size distribution range of the spraying feed powder is more than 50-80 μm or more than 50-80 μm, Yb with uniformly distributed complex phase eutectoid structure is difficult to prepare 2 Si 2 O 7 -Yb 2 SiO 5 And (3) a complex phase eutectoid surface layer.
Comparative example 3
In the comparative example 3, the complex phase eutectoid environmental barrier coating is obtained according to the process of the comparative example 2, and the CMAS corrosion resistance performance test is performed on the complex phase eutectoid environmental barrier coating under the same experimental conditions as those in the example 5.
As shown in FIG. 8(a), the cross-sectional morphology of the complex phase eutectoid environmental barrier coating after being corroded by CMAS for 4h at 1300 ℃, as can be seen from the figure, the corrosion depth of the coating is 80 μm.
As shown in FIG. 8(b), the cross-sectional morphology of the complex phase eutectoid environmental barrier coating after CMAS corrosion for 50h at 1300 ℃, as can be seen from the figure, the CMAS melt has penetrated to the interface of the Si bonding layer and the surface layer, and the corrosion depth of the coating is greater than the thickness of the coating by 100 μm.
Yb prepared in example 5 and comparative example 3 2 Si 2 O 7 -Yb 2 SiO 5 The results of the test of the CMAS corrosion resistance of the complex phase eutectoid surface layer are shown in Table 1.
Table 1: yb prepared in example 5 and comparative example 3 2 Si 2 O 7 -Yb 2 SiO 5 Test result of CMAS corrosion resistance performance of complex phase eutectoid surface layer
| Examples | Depth of corrosion (μm) after 4h of CMAS corrosion | Depth of corrosion (μm) after 50h of CMAS corrosion |
| Example 5 | 52 | 70 |
| Comparative example 3 | 80 | ＞100 |
As shown in Table 1, it is understood that single-phase Yb having a particle size distribution of 50 to 80 μm is used 2 Si 2 O 7 Yb produced by spraying of spherical feedstock 2 Si 2 O 7 -Yb 2 SiO 5 The complex phase eutectoid surface layer has better high temperature CMAS corrosion resistance.
The results of the above examples show that the present invention employs single-phase Yb 2 Si 2 O 7 The spherical feeding is sprayed, and by controlling the spraying flow and the heat treatment process, the multiphase eutectoid environment barrier coating prepared in situ has high crystallization degree, uniform mutual embedding of two phases, excellent comprehensive performance of gas thermal shock cycle life resistance and high temperature CMAS corrosion resistance, and can greatly improve the service reliability and stability of the environment barrier coating in the engine gas environment.
Claims (10)
1. The complex phase eutectoid environmental barrier coating is characterized in that the complex phase eutectoid environmental barrier coating sequentially comprises a Si bonding layer, Yb composed of ytterbium disilicate and ytterbium monosilicate from a substrate to the outside 2 Si 2 O 7 -Yb 2 SiO 5 Composition of heterogeneous eutectoid surface layer, Yb 2 Si 2 O 7 -Yb 2 SiO 5 The bi-silicate ytterbium phase and the mono-silicate ytterbium phase in the complex phase eutectoid surface layer present uniform mutual embedded distribution on a nanometer scale, Yb 2 Si 2 O 7 -Yb 2 SiO 5 The phase composition of the complex phase eutectoid surface layer comprises Yb 2 Si 2 O 7 And Yb 2 SiO 5 ，Yb 2 Si 2 O 7 The content of (A) is 60-90 wt.%.
2. The impact thermal cycle and CMAS corrosion resistant heterogeneous eutectoid environmental barrier coating of claim 1, wherein Yb is 2 Si 2 O 7 -Yb 2 SiO 5 The crystallization degree of the complex phase eutectoid surface layer is high.
3. The impact-resistant thermal cycle and CMAS corrosion-resistant complex-phase eutectoid environmental barrier coating according to claim 1, wherein the Si bonding layer has a thickness of 50 to 150 μm and Yb 2 Si 2 O 7 -Yb 2 SiO 5 The thickness of the complex phase eutectoid surface layer is 50-300 mu m.
4. The method for preparing a complex eutectoid environmental barrier coating with impact resistance, thermal cycling resistance and CMAS corrosion resistance according to any one of claims 1 to 3, characterized in that the method comprises the following steps:
1) preparing a Si bonding layer on the surface of the silicon carbide substrate material by adopting an atmospheric plasma spraying technology;
2) in single phase Yb 2 Si 2 O 7 Spraying spherical feed as raw material, and preparing Yb in situ on the surface of Si bonding layer by atmospheric plasma spraying technique 2 Si 2 O 7 -Yb 2 SiO 5 A complex phase eutectoid surface layer;
3) and carrying out heat treatment on the silicon carbide substrate with the sprayed bonding layer and the sprayed surface layer to obtain the high-crystallization-degree complex phase eutectoid environmental barrier coating.
5. The method of claim 4, wherein the coating is a single phase Yb coating, and wherein the coating is a heterogeneous eutectoid environmental barrier coating with resistance to thermal cycling and CMAS corrosion 2 Si 2 O 7 The spray ball feed is prepared by the following steps:
step 1. mixing single phase Yb 2 Si 2 O 7 Uniformly mixing powder, deionized water, a polyvinyl alcohol binder (PVA), a polyethyleneimine dispersant (PEI) and a polyethylene glycol Plasticizer (PEG) to obtain slurry; transferring the slurry to a spray drying granulation tower for agglomeration granulation to obtain spherical agglomeration granulation powder with the particle size of 50-80 microns;
step 2, calcining the obtained spherical agglomeration granulation powder at 1200-1400 ℃ to remove the glue to obtain single-phase Yb 2 Si 2 O 7 Spray coating of spherical feed, single phase Yb 2 Si 2 O 7 The particle size range of the spraying spherical feed is 50-80 mu m.
6. The method for preparing the impact thermal cycle and CMAS corrosion resistant complex-phase eutectoid environmental barrier coating according to claim 5, wherein the solid content of the slurry in step 1 is more than or equal to 40 wt.%; the addition amount of the polyvinyl alcohol binder is more than or equal to 0.5 wt.%; the addition amounts of the polyethyleneimine dispersant (PEI) and the polyethylene glycol Plasticizer (PEG) are respectively less than or equal to 2.0 wt.%.
7. The preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex-phase eutectoid environmental barrier coating according to claim 5, wherein before the preparation of the Si bonding layer, the silicon carbide substrate material is cleaned and roughened, so that the roughness Ra of the surface to be sprayed reaches 1-8 μm; further, heating the silicon carbide substrate material by adopting plasma flame flow to ensure that the surface temperature of the silicon carbide substrate material reaches 200-500 ℃.
8. The method for preparing the impact-resistant thermal cycle and CMAS corrosion-resistant complex-phase eutectoid environmental barrier coating according to claim 4, wherein in the step 1), the preparation parameters of the Si bonding layer comprise: argon and hydrogen or argon and helium are used as plasma gas, the flow of the argon is 40-60 slpm, the flow of the hydrogen is 5-15 slpm, the flow of the helium is 5-15 slpm, the spraying distance is 90-200 mm, the arc current is 200-600A, and the powder feeding rate of the spraying feeding is 10-50%.
9. The method for preparing the anti-impact thermal cycle and CMAS corrosion-resistant complex-phase eutectoid environmental barrier coating according to claim 4, wherein in the step 2), Yb 2 Si 2 O 7 -Yb 2 SiO 5 The preparation parameters of the complex phase eutectoid surface layer comprise: the method is characterized in that argon and hydrogen or argon and helium are used as plasma gas, the flow of the argon is 40-90 slpm, the flow of the hydrogen is 5-20 slpm, the flow of the helium is 5-20 slpm, the spraying distance is 90-200 mm, and the arc current is 200-600A, the spraying feeding powder feeding speed is 10-50%.
10. The preparation method of the impact-resistant thermal cycle and CMAS corrosion-resistant complex-phase eutectoid environmental barrier coating according to claim 4, wherein in the step 3), the heat treatment eutectoid crystallization temperature is more than or equal to 1000 ℃; the heat treatment time is more than or equal to 1 h; the heat treatment atmosphere was argon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210700244.5A CN114988895A (en) | 2022-06-20 | 2022-06-20 | Impact-resistant thermal cycle and CMAS corrosion resistant complex phase eutectoid environmental barrier coating and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210700244.5A CN114988895A (en) | 2022-06-20 | 2022-06-20 | Impact-resistant thermal cycle and CMAS corrosion resistant complex phase eutectoid environmental barrier coating and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114988895A true CN114988895A (en) | 2022-09-02 |
Family
ID=83037252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210700244.5A Pending CN114988895A (en) | 2022-06-20 | 2022-06-20 | Impact-resistant thermal cycle and CMAS corrosion resistant complex phase eutectoid environmental barrier coating and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114988895A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116253584A (en) * | 2023-02-15 | 2023-06-13 | 中国航发北京航空材料研究院 | Full-oxide thermal/environmental barrier coating for ceramic matrix composite material and preparation method thereof |
| CN116425192A (en) * | 2023-02-06 | 2023-07-14 | 北京伽瓦新材料科技有限公司 | Powder material special for PS-PVD, preparation method and application |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100129636A1 (en) * | 2008-11-25 | 2010-05-27 | Rolls-Royce Corporation | Abradable layer including a rare earth silicate |
| CN109468574A (en) * | 2017-09-07 | 2019-03-15 | 中国科学院上海硅酸盐研究所 | A kind of high temperature resistant environment barrier coating and preparation method |
| CN111876714A (en) * | 2020-07-07 | 2020-11-03 | 航天特种材料及工艺技术研究所 | Complex phase environmental barrier coating formed on substrate material and preparation method thereof |
| CN112662982A (en) * | 2019-10-15 | 2021-04-16 | 哈尔滨工业大学 | Nano-structure Yb suitable for plasma spraying2Si2O7Preparation method of spherical feed |
| CN113860920A (en) * | 2021-09-13 | 2021-12-31 | 中国科学院金属研究所 | Environmental barrier coating with excellent CMAS corrosion resistance and preparation method thereof |
| CN114354477A (en) * | 2022-01-17 | 2022-04-15 | 中国人民解放军国防科技大学 | Nondestructive testing and evaluation method for environmental barrier coating |
-
2022
- 2022-06-20 CN CN202210700244.5A patent/CN114988895A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100129636A1 (en) * | 2008-11-25 | 2010-05-27 | Rolls-Royce Corporation | Abradable layer including a rare earth silicate |
| CN109468574A (en) * | 2017-09-07 | 2019-03-15 | 中国科学院上海硅酸盐研究所 | A kind of high temperature resistant environment barrier coating and preparation method |
| CN112662982A (en) * | 2019-10-15 | 2021-04-16 | 哈尔滨工业大学 | Nano-structure Yb suitable for plasma spraying2Si2O7Preparation method of spherical feed |
| CN111876714A (en) * | 2020-07-07 | 2020-11-03 | 航天特种材料及工艺技术研究所 | Complex phase environmental barrier coating formed on substrate material and preparation method thereof |
| CN113860920A (en) * | 2021-09-13 | 2021-12-31 | 中国科学院金属研究所 | Environmental barrier coating with excellent CMAS corrosion resistance and preparation method thereof |
| CN114354477A (en) * | 2022-01-17 | 2022-04-15 | 中国人民解放军国防科技大学 | Nondestructive testing and evaluation method for environmental barrier coating |
Non-Patent Citations (1)
| Title |
|---|
| HAOYU WANG: "Microstructure and phase composition evolution of dual-phase ytterbium silicate coatings plasma sprayed from stoichiometric Yb2Si2O7 feedstock powder", 《SURFACE & COATINGS TECHNOLOGY》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116425192A (en) * | 2023-02-06 | 2023-07-14 | 北京伽瓦新材料科技有限公司 | Powder material special for PS-PVD, preparation method and application |
| CN116425192B (en) * | 2023-02-06 | 2023-11-14 | 北京伽瓦新材料科技有限公司 | Powder material special for PS-PVD, preparation method and application |
| CN116253584A (en) * | 2023-02-15 | 2023-06-13 | 中国航发北京航空材料研究院 | Full-oxide thermal/environmental barrier coating for ceramic matrix composite material and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114988895A (en) | Impact-resistant thermal cycle and CMAS corrosion resistant complex phase eutectoid environmental barrier coating and preparation method thereof | |
| CN111004990B (en) | MAX phase coating for thermal barrier coating anti-melting CMAS corrosion and thermal spraying preparation method | |
| CN107032796B (en) | Self-healing SiC/ZrSi2-MoSi2Coating material and preparation method | |
| CN112592207A (en) | Self-healing ZrB2-SiC-Y2O3Coating and application thereof to SiC-embedded carbon-carbon composite material | |
| CN111777413B (en) | Preparation method and application of nano gadolinium zirconate powder for plasma spraying | |
| CN109837496A (en) | A kind of preparation method of ytterbium silicate plasma spraying powder | |
| CN110981546A (en) | Anti-oxidation ZrB on surface of C-C composite material2-SiC-Y2O3Coating and method for producing the same | |
| CN114000089A (en) | High-entropy oxide ultra-high temperature thermal barrier coating prepared by APS technology and method thereof | |
| CN114000107A (en) | High-entropy oxide ultra-high temperature thermal barrier coating prepared by EB-PVD (electron beam-physical vapor deposition) technology and method thereof | |
| CN101078117A (en) | Method for preparing heat barrier coating with column form crystal structure ceramic layer | |
| CN115124339A (en) | Multi-element high-entropy doped zirconia-based ceramic material and preparation method and application thereof | |
| CN113860920B (en) | Environmental barrier coating with excellent CMAS corrosion resistance and preparation method thereof | |
| CN102674874A (en) | ZrC-SiC-LaB6 ternary superhigh temperature ceramic composite material and preparation method thereof | |
| CN114479531A (en) | Conductive abradable seal coating material and preparation method thereof | |
| CN113699479A (en) | Method for improving CMAS corrosion resistance of thermal barrier coating | |
| CN110205626A (en) | A kind of functionally gradient thermal barrier coating and preparation method thereof | |
| CN113233883A (en) | Quaternary rare earth silicate solid solution spherical agglomerated powder and preparation method thereof | |
| CN115537808B (en) | Method for depositing high-entropy alloy coating on surface of ceramic matrix composite | |
| CN110872713B (en) | Y/Y2O3Cold spraying preparation method of metal ceramic protective coating | |
| CN115073172B (en) | Ceramic target material and preparation method and application thereof | |
| CN114574798B (en) | High-strain-tolerance anti-sintering thermal barrier coating structure design and preparation method | |
| CN114086102A (en) | Ba (Mg)1/3Ta2/3)O3-YSZ double-ceramic-layer thermal barrier coating and preparation method thereof | |
| CN114000090A (en) | Preparation method of oxide/oxide composite material surface environmental barrier coating | |
| CN112299883B (en) | High-temperature-resistant protective coating of silicon carbide heating element and preparation method thereof | |
| CN114213155A (en) | Hafnium diboride-silicon carbide-tantalum disilicide-gadolinium oxide composite coating and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |