A high-thermal-shock-resistant arched ceramic coating part, a preparation method thereof and an aero-engine

Abstract

The application provides a high thermal shock resistance arched ceramic coating part and a preparation method and an aero-engine, and relates to the technical field of ceramic coating. The high thermal shock resistance arched ceramic coating part comprises an arched alloy base material and an arched ceramic coating arranged on the surface of the arched alloy base material; the arched ceramic coating comprises a bottom layer, an intermediate layer and a surface layer which are sequentially arranged, and the bottom layer is adjacent to the arched alloy base material; the arched alloy base material comprises a nickel-based high-temperature alloy; the bottom layer comprises an MCrAlYHfSi alloy; the intermediate layer comprises nano-zirconium oxide and Y2O3; the surface layer comprises ytterbium oxide, gadolinium oxide and yttrium oxide modified zirconium oxide; the elastic modulus of the bottom layer, the intermediate layer and the surface layer is sequentially increased, and the thermal expansion coefficient is sequentially decreased. The arched structure design of the arched alloy base material and the arched ceramic coating is adopted, the stress distribution mode of the traditional plane coating is changed, the stress concentration is reduced, and the thermal shock resistance of the coating is enhanced.

Description

Technical Field

[0001] This application relates to the field of ceramic coating technology, and in particular to a high thermal shock resistant arched ceramic coated part, its preparation method, and an aero-engine. Background Technology

[0002] As the core power plant of aircraft, the turbine blades, combustion chamber, and other hot-end components of the aero-engine are key factors determining the engine's thrust-to-weight ratio, reliability, and lifespan. During service, these components not only have to withstand the scouring of high-temperature exhaust gases exceeding 1150°C (the hot-end temperature of some advanced engine models has exceeded 1400°C), but also have to endure drastic temperature fluctuations (temperature difference can reach over 1000°C) during start-up and shutdown phases. Frequent thermal expansion and contraction can easily trigger severe thermal shock effects.

[0003] To cope with extreme working conditions, the industry commonly adopts a composite structure of "metal substrate + ceramic coating," using the high temperature resistance and low thermal conductivity of the ceramic coating to protect the metal substrate. However, existing technologies mostly employ planar ceramic coating designs, which have two major drawbacks: First, planar structures cannot effectively disperse the linear thermal stress generated by thermal shock, easily forming stress concentration zones within the coating and at the coating-substrate interface, leading to coating cracking and peeling. Second, traditional coatings have poor matching between the interlayer thermal expansion coefficient and elastic modulus; for example, the difference in thermal expansion coefficient between the bottom metal bonding layer (such as ordinary MCrAlY alloy) and the top ceramic layer (such as yttrium-stabilized zirconia) often exceeds 5 × 10⁻⁶. -6 / ℃, the difference in elastic modulus can reach more than 100GPa, and the interface peeling is easily caused by the incoordination of interlayer deformation during hot and cold cycles.

[0004] Furthermore, as aero-engine thrust-to-weight ratios approach 15 or higher, the service temperatures of hot-end components are rising further. The thermal shock resistance life of traditional planar coatings (typically less than 20 cycles from 1150°C to room temperature) is no longer sufficient for long-term use. Simultaneously, corrosion from calcium magnesium aluminum silicate (CMAS) molten salts and combustion gas at high temperatures further exacerbate the risk of coating failure, leading to frequent replacements and high maintenance costs for hot-end components, becoming a key bottleneck restricting the improvement of aero-engine performance. Therefore, developing a ceramic coating structure that can adapt to the operating conditions of hot-end components, effectively disperse thermal stress, and improve thermal shock resistance and protection has become a pressing technical problem for the industry. Summary of the Invention

[0005] The purpose of this application is to provide a high thermal shock resistant arched ceramic coated part, its preparation method, and an aero-engine to solve the above-mentioned problems.

[0006] To achieve the above objectives, the first aspect of this application provides a high thermal shock resistant arched ceramic coating part, comprising an arched alloy substrate and an arched ceramic coating disposed on the surface of the arched alloy substrate;

[0007] The arched ceramic coating comprises a bottom layer, an intermediate layer, and a top layer stacked sequentially, wherein the bottom layer is adjacent to the arched alloy substrate.

[0008] The arched alloy substrate includes a nickel-based high-temperature alloy, specifically a mature and highly adaptable model such as GH4169 or GH5188.

[0009] The underlying layer comprises an MCrAlYHfSi alloy, wherein M includes Ni and Co;

[0010] The intermediate layer comprises nano-zirconia and Y2O3;

[0011] The surface layer comprises ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconium oxide;

[0012] The elastic modulus of the bottom layer, the middle layer, and the top layer increases sequentially, while the coefficient of thermal expansion decreases sequentially.

[0013] Optionally, the highly thermally shock resistant arched ceramic-coated part satisfies at least one of the following conditions:

[0014] A. The coefficient of thermal expansion of the bottom layer is 12 × 10⁻⁶. -6 / ℃-15×10 -6 / ℃;

[0015] B. The coefficient of thermal expansion of the intermediate layer is 9 × 10⁻⁶. -6 / ℃-12×10 -6 / ℃;

[0016] C. The coefficient of thermal expansion of the surface layer is 6 × 10⁻⁶. -6 / ℃-8×10 -6 / ℃;

[0017] D. The coefficient of thermal expansion of the arched alloy substrate is 11 × 10⁻⁶. -6 / ℃-15×10 -6 / ℃;

[0018] E. The elastic modulus of the underlying layer is ≤150 GPa;

[0019] F. The elastic modulus of the intermediate layer is 180-220 GPa;

[0020] G. The elastic modulus of the surface layer is ≥250 GPa;

[0021] H. The elastic modulus of the arched alloy substrate is 140-180 GPa.

[0022] Optionally, the highly thermally shock resistant arched ceramic-coated part satisfies at least one of the following conditions:

[0023] A. The thickness of the bottom layer accounts for 20%-30% of the thickness of the arched ceramic coating;

[0024] B. The thickness of the intermediate layer accounts for 30%-40% of the thickness of the arched ceramic coating;

[0025] C. The thickness of the surface layer accounts for 30%-40% of the thickness of the arched ceramic coating;

[0026] D. The average porosity of the intermediate layer is 5-10%, the porosity at the apex is 8-10%, and the porosity at the edge is 5-7%;

[0027] E. The mass ratio of the ytterbium oxide, the gadolinium oxide, and the yttrium oxide-modified zirconium oxide is 1-2:1-1.5:2-3;

[0028] F. The thickness of the arched ceramic coating is 0.3mm-0.8mm;

[0029] G. The mass ratio of Y2O3 to nano-zirconia is 3-5:95-97.

[0030] Optionally, the highly thermally shock resistant arched ceramic-coated part satisfies at least one of the following conditions:

[0031] A. The curvature difference between the arched alloy substrate and the arched ceramic coating is less than or equal to 2%;

[0032] B. The radius of curvature of the arched alloy substrate is 15-35 mm;

[0033] C. The bonding strength between the arched alloy substrate and the arched ceramic coating is greater than 40 MPa;

[0034] D. The MCrAlYHfSi alloy, based on a total mass of 100%, comprises:

[0035] 35-45% Ni, 15-25% Co, 15-20% Cr, 8-12% Al, 0.1-0.5% Y, 0.5-2%Hf, 0.1-1% Si.

[0036] A second aspect of this application provides a method for preparing the aforementioned high thermal shock resistant arched ceramic coated part, comprising:

[0037] An arched alloy substrate is provided, and the arched alloy substrate is pretreated to obtain a pretreated substrate;

[0038] Using argon as the carrier gas, MCrAlYHfSi alloy powder was subjected to a first plasma spraying on the surface of the arched alloy substrate to obtain the bottom layer;

[0039] A second plasma spraying of nano-zirconia powder and Y2O3 is performed on the surface of the bottom layer to obtain an intermediate layer;

[0040] Ternary rare earth powder is subjected to a third plasma spraying on the surface of the intermediate layer to obtain a substrate with a top layer after spraying.

[0041] In a vacuum environment, the coated substrate is heated to obtain a highly thermally shock resistant arched ceramic coated part.

[0042] The ternary rare earth powder includes ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconium oxide powder.

[0043] Optionally, the method for preparing the high thermal shock resistant arched ceramic coated part satisfies at least one of the following conditions:

[0044] A. The arched alloy substrate is prepared by isostatic pressing or mechanical cutting.

[0045] The isostatic pressing process includes: sequentially performing hot isostatic pressing and machining on the raw material of the arched alloy substrate;

[0046] The mechanical cutting process includes: cutting the alloy substrate using a cutting tool or a laser beam;

[0047] B. The pretreatment includes sandblasting roughening and cleaning;

[0048] The abrasive particle size for the sandblasting roughening is 80-120 mesh, and the sandblasting pressure is 0.3-0.5 MPa;

[0049] C. The deposited bottom layer, the intermediate layer and the top layer are cooled respectively, and the final temperature of the cooling is 80-120℃.

[0050] Optionally, the method for preparing the high thermal shock resistant arched ceramic coated part satisfies at least one of the following conditions:

[0051] A. The hot isostatic pressing process is performed at a pressure of 150-250 MPa, a temperature of 800-1000℃, and a holding time of 2-4 hours.

[0052] B. In the mechanical cutting process, the cutting speed of the cutting tool is 5000-15000 r / min, and the feed speed is 500-3000 mm / min;

[0053] The laser beam has a power of 0.5-5kW and a cutting speed of 0.2-3m / min.

[0054] Optionally, the method for preparing the high thermal shock resistant arched ceramic coated part satisfies at least one of the following conditions:

[0055] A. During the first plasma spraying process, the working gas includes hydrogen and argon, the flow rate of hydrogen is 5-8 L / min, the flow rate of argon is 40-50 L / min, the spraying power is 30-40 kW, the powder feeding speed is 15-25 g / min, the spraying distance is 80-100 mm, the flow rate of the carrier gas is 8-10 L / min, and the residence time of the MCrAlYHfSi alloy powder in the flame is 0.5-1 ms;

[0056] B. During the second plasma spraying process, the working gas includes hydrogen and argon, the flow rate of hydrogen is 6-9 L / min, the flow rate of argon is 45-55 L / min, the spraying power is 35-45 kW, the powder feeding speed is 12-18 g / min, the spraying distance is 90-110 mm, the flow rate of carrier gas is 8-10 L / min, and the flame temperature is 12000-14000℃;

[0057] C. During the third plasma spraying process, the working gas includes hydrogen and argon, the flow rate of hydrogen is 8-12 L / min, the flow rate of argon is 50-60 L / min, the spraying power is 40-50 kW, the flame temperature is 14000-16000℃, the powder feeding speed is 15-20 g / min, the carrier gas flow rate is 10-12 L / min, and the spraying distance is 80-100 mm;

[0058] D. The MCrAlYHfSi alloy powder has a particle size of 50-100 μm and a loose packing density of 3.5-4.0 g / cm³. 3 ;

[0059] E. The nano-zirconia powder has a particle size of 50-80 μm and a loose packing density of 2.0-2.5 g / cm³. 3 ;

[0060] F. The particle size of the ternary rare earth powder is 50-80 nm, and the loose packing density is 2.8-3.2 g / cm³. 3 .

[0061] Optionally, the heating rate of the heating treatment is 5-10℃ / min, the final temperature is 800-1000℃, the holding time is 2-4h, and the cooling rate is 3-5℃ / min.

[0062] A third aspect of this application provides an aircraft engine including the aforementioned high thermal shock resistant arched ceramic coated part.

[0063] Compared with the prior art, the beneficial effects of this application include:

[0064] The high thermal shock resistant arched ceramic coating parts provided in this application firstly employ an arched structure design that matches the arched alloy substrate with the arched ceramic coating. This changes the stress distribution pattern of traditional planar coatings, allowing for uniform dispersion of thermal stress during thermal shock through the curved surface geometry, reducing stress concentration and enhancing the coating's thermal shock resistance. Secondly, the arched ceramic coating adopts a composite structure of "bottom layer-intermediate layer-top layer," with a gradient change in the coefficient of thermal expansion from high to low and the elastic modulus from low to high. The bottom layer is an MCrAlYHfSi alloy, which, with its high adhesion and flexibility, ensures a firm bond with the arched alloy substrate and buffers thermal stress, reducing interfacial stress. The intermediate layer, as a transition buffer, uses nano-zirconia, utilizing the phase transformation toughening and high specific surface area characteristics of nanoparticles to absorb thermal stress and enhance interlayer bonding, further alleviating interlayer stress differences. The top layer uses ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconia. The synergistic modification of these three rare earth elements enhances the coating's high-temperature resistance and thermal shock resistance, providing high-strength thermal shock resistance and wear-resistant protection.

[0065] The method for preparing high thermal shock resistant arched ceramic coated parts provided in this application has beneficial effects in three aspects: In terms of product performance, the arched structure and gradient coating work together to achieve more than 35 thermal shock cycles from 1150℃ to room temperature (compared to about 15 cycles in the traditional method), the bonding strength between the substrate and the coating exceeds 40MPa (compared to 25MPa in the traditional method), the surface layer's resistance to CMAS corrosion is improved by 30%, the penetration rate is reduced by 50%, and the coating's thermal insulation can also cool the substrate by 100-200℃, extending the component's lifespan to more than twice that of the traditional method; In terms of process implementation, layered spraying and vacuum heating achieve precise control of the coating gradient (curvature difference ≤2%), increasing the pass rate by 25% compared to the traditional method, the preparation of the arched substrate does not require complex equipment, the cost is reduced by 1 / 3 and it can be mass-produced; In terms of application value, it is suitable for aero-engine operating conditions above 1400℃, helping to increase the potential for improving the engine's thrust-to-weight ratio by 10%, extending the component maintenance cycle by 6-8 months, reducing the overall operation and maintenance cost by more than 20%, and solving the problems of weak thermal shock resistance, easy peeling, and difficulty in mass production of traditional planar coatings.

[0066] The aircraft engine provided in this application has good thermal shock resistance and wear resistance. Attached Figure Description

[0067] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0068] Figure 1 A physical image of the high thermal shock resistant arched ceramic coating part provided in Example 1. Detailed Implementation

[0069] As used in this article:

[0070] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0071] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0072] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0073] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0074] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0075] The first aspect of this application provides a high thermal shock resistant arched ceramic coating part, including an arched alloy substrate and an arched ceramic coating disposed on the surface of the arched alloy substrate;

[0076] It is important to note that substrates are prone to significant thermal stress due to drastic temperature changes, leading to high-temperature deformation and subsequent coating peeling. The arched structure, through its unique geometric shape and mechanical properties, can effectively mitigate the impact of substrate deformation on the coating, as detailed below:

[0077] 1. Stress Dispersion Mechanism: The curved surface of the arched structure can transform the linear thermal stress generated during thermal shock into compressive stress distributed along the curved surface. Utilizing the mechanical properties of the arch, concentrated stress is dispersed across the entire structural surface, reducing local stress peaks. Compared to planar structures, its stress distribution is more uniform, reducing substrate deformation and coating cracking caused by stress concentration. When the substrate undergoes thermal deformation, the curvature change of the arched structure can absorb some of the thermal stress through elastic deformation, preventing stress from being directly transmitted to the interface between the coating and the substrate, thereby reducing the stress level at the interface and decreasing the risk of coating peeling.

[0078] 2. Compared with planar structures, the curved shape of arched structures increases the contact area between the coating and the substrate. Under the same thermal stress, the stress load per unit area is reduced, which further reduces the stress impact on the coating and improves the coating's resistance to peeling.

[0079] 3. Enhanced thermal shock protection: The curved geometric characteristics of the arched structure can change the distribution path of heat flow, making the heat transfer on the coating surface more uniform, reducing local overheating, and thus reducing the amount of deformation of the substrate caused by uneven temperature.

[0080] The arched ceramic coating comprises a bottom layer, an intermediate layer, and a top layer stacked sequentially, wherein the bottom layer is adjacent to the arched alloy substrate.

[0081] The arched alloy substrate includes a nickel-based high-temperature alloy; specifically, mature and highly adaptable models such as GH4169 and GH5188 can be used; the bottom layer includes an MCrAlYHfSi alloy, wherein M includes Ni and Co;

[0082] The intermediate layer comprises nano-zirconia and Y2O3;

[0083] The surface layer comprises ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconium oxide;

[0084] The elastic modulus of the bottom layer, the middle layer, and the top layer increases sequentially, while the coefficient of thermal expansion decreases sequentially.

[0085] It is important to note that the coefficient of thermal expansion gradually decreases from the bottom layer to the top layer, while the elastic modulus gradually increases. This, combined with the arched structure, further alleviates the stress difference between layers. During thermal shock, the stress dispersion characteristics of the arched structure and the stress buffering effect of the gradient coating work together to reduce the maximum interfacial stress of the coating structure by more than 60% compared to traditional homogeneous coatings, significantly improving thermal shock resistance. In addition, the arched shape of the arched alloy substrate and the arched ceramic coating forms a dynamic coupling with the stress distribution of the arched ceramic coating on the surface of the arched alloy substrate. When thermal shock occurs, the curvature of the bottom layer (with the highest coefficient of thermal expansion) and the substrate deforms in tandem, converting linear thermal stress into tangential compressive stress along the curved surface. The gradient elastic modulus (8-12% / μm) of the middle layer further disperses stress through the bending moment of the curved surface, reducing the interfacial stress by more than 60% compared to the traditional planar three-layer structure.

[0086] It should also be noted that the structure of the arched ceramic coating exhibits a gradient distribution along the normal direction of the curved surface, with decreasing coefficient of thermal expansion and increasing elastic modulus, which complements the mechanical properties of the arched structure.

[0087] 1. The underlying high-ductility material (MCrAlYHfSi) provides cushioning when the arched substrate deforms, preventing coating tearing caused by changes in curvature;

[0088] 2. The porosity (5-10%) of the intermediate nano-zirconia layer, together with the arched surface, absorbs thermal stress through the elastic deformation of the pores and the geometric retreat of the surface;

[0089] 3. The rare earth modified zirconium oxide with high elastic modulus on the surface forms a compressive stress protection layer at the top of the arch, which offsets the tensile stress concentration during thermal shock.

[0090] In some comparative examples, when both the alloy substrate and the ceramic coating are planar, the phase thermal stress concentration of the planar structure prevents the phase transformation toughening effect of the coating from being fully utilized. Furthermore, the abrupt change in the thermal expansion coefficient between the bottom layer and the intermediate layer can easily lead to interfacial delamination. In contrast, the arched structure disperses stress through the curved surface, effectively improving the phase transformation toughening efficiency of nano-zirconia. The arched ceramic coating, through dual adjustment of curvature and material, transforms the difference in thermal expansion into a distribution gradient along the curved surface, eliminating abrupt stress.

[0091] In some embodiments, the highly thermally shock resistant arched ceramic-coated part satisfies at least one of the following conditions:

[0092] A. The coefficient of thermal expansion of the bottom layer is 12 × 10⁻⁶. -6 / ℃-15×10 -6 / ℃;

[0093] Optionally, the coefficient of thermal expansion of the bottom layer can be 12×10⁻⁶. -6 / ℃, 13×10 -6 / ℃, 14×10 -6 / ℃, 15×10 -6 / ℃ or 12×10 -6 / ℃-15×10 -6 Any value between / ℃;

[0094] B. The coefficient of thermal expansion of the intermediate layer is 9 × 10⁻⁶. -6 / ℃-12×10 -6 / ℃;

[0095] Optionally, the coefficient of thermal expansion of the intermediate layer can be 9 × 10⁻⁶. -6 / ℃, 10×10 -6 / ℃, 11×10 -6 / ℃, 12×10 -6 / ℃ or 9×10 -6 / ℃-12×10 -6 Any value between / ℃;

[0096] C. The coefficient of thermal expansion of the surface layer is 6 × 10⁻⁶. -6 / ℃-8×10 -6 / ℃;

[0097] Optionally, the coefficient of thermal expansion of the surface layer can be 6×10⁻⁶. -6 / ℃, 7×10 -6 / ℃, 8×10 -6 / ℃ or 6×10 -6 / ℃-8×10 -6 Any value between / ℃;

[0098] It is important to note that the three layers—bottom, middle, and top—form a decreasing coefficient of thermal expansion along the normal direction of the arch, matching the thermal stress distribution curve of the arch structure. For example, the bottom layer has a higher coefficient of thermal expansion than the middle layer, ensuring that the bottom layer undergoes elastic deformation first when the substrate deforms in an arch, thus avoiding interfacial tearing.

[0099] D. The coefficient of thermal expansion of the arched alloy substrate is 11 × 10⁻⁶. -6 / ℃-15×10 -6 / ℃;

[0100] Optionally, the coefficient of thermal expansion of the arched alloy substrate can be 11 × 10⁻⁶. -6 / ℃, 12×10 -6 / ℃, 13×10 -6 / ℃, 14×10 -6 / ℃, 15×10 -6 / ℃ or 11×10 -6 / ℃-15×10 -6 Any value between / ℃;

[0101] E. The elastic modulus of the underlying layer is ≤150 GPa;

[0102] Optionally, the elastic modulus of the underlying layer can be any value of 1 GPa, 10 GPa, 50 GPa, 100 GPa, 150 GPa or ≤150 GPa;

[0103] It is important to note that the high coefficient of thermal expansion (higher than the intermediate layer) and low elastic modulus (≤150GPa) of the bottom layer are well-suited to the thermal deformation characteristics of the arched metal substrate. When the radius of curvature of the arched substrate fluctuates by ±2% during thermal shock, the bottom layer absorbs the deformation energy of the substrate through plastic deformation, preventing coating peeling due to inconsistent deformation (bonding strength >40MPa). The layered structure of the MCrAlYHfSi alloy extends along the arched surface, and the grain boundary slip mechanism can buffer the shear stress generated by the surface deformation, improving the shear resistance of the bottom layer by 30% compared to the planar coating.

[0104] F. The elastic modulus of the intermediate layer is 180-220 GPa;

[0105] Optionally, the elastic modulus of the intermediate layer can be 180 GPa, 190 GPa, 200 GPa, 210 GPa, 220 GPa or any value between 180 and 220 GPa;

[0106] It is important to note that the zirconia particles in the intermediate layer form a "micro-spring" structure on the arched surface. During thermal vibration, the average porosity (5-10%) between the nanoparticles can be compressed or expanded as the curvature of the arch changes, absorbing the strain energy generated by the deformation of the surface. For example, when the radius of curvature at the top of the arch shrinks from 30 mm to 29 mm, the porosity of the intermediate layer can temporarily increase by 2-3%, relieving local stress. The elastic modulus of the intermediate layer (180-220 GPa) is between that of the bottom layer and the top layer. When the arched structure bends, it coordinates the stress difference between the upper and lower layers through moderate elastic deformation, avoiding interlayer delamination caused by abrupt changes in modulus.

[0107] G. The elastic modulus of the surface layer is ≥250 GPa;

[0108] Optionally, the elastic modulus of the surface layer can be any value of 250 GPa, 300 GPa, 350 GPa, 400 GPa, 500 GPa or ≥250 GPa;

[0109] It is important to note that the surface layer has the lowest coefficient of thermal expansion, which is 15-20% lower than that of the intermediate layer. This forms a "compressive stress shell" on the arched surface. During thermal shock, the outer surface of the arch tends to shrink due to the sudden drop in temperature. The low expansion characteristics of the surface layer can suppress this shrinkage and convert it into beneficial compressive stress (≥100MPa), which offsets the normal tensile stress. The surface layer with an elastic modulus ≥250GPa forms a rigid support at the apex of the arch, preventing excessive deformation of the curved surface. For example, during thermal shock at 1150℃, the surface layer can control the deflection at the apex of the arch to within 0.05mm, preventing the coating from cracking due to excessive bending.

[0110] H. The elastic modulus of the arched alloy substrate is 140-180 GPa.

[0111] Optionally, the elastic modulus of the arched alloy substrate can be 140 GPa, 150 GPa, 160 GPa, 170 GPa, 180 GPa or any value between 140 and 180 GPa.

[0112] In some embodiments, the highly thermally shock resistant arched ceramic-coated part satisfies at least one of the following conditions:

[0113] A. The thickness of the underlying layer accounts for 20%-30% of the thickness of the arched ceramic coating;

[0114] Optionally, the thickness of the base layer can be any value between 20%, 25%, 30%, or 20%-30% of the arched ceramic coating;

[0115] B. The thickness of the intermediate layer accounts for 30%-40% of the thickness of the arched ceramic coating;

[0116] Optionally, the thickness of the intermediate layer can be any value between 30%, 35%, 40%, or 30-40% of the arched ceramic coating;

[0117] C. The thickness of the surface layer accounts for 30%-40% of the thickness of the arched ceramic coating;

[0118] Optionally, the surface layer thickness can be any value between 30%, 35%, 40%, or 30-40% of the arched ceramic coating;

[0119] D. The average porosity of the intermediate layer is 5-10%, the porosity at the apex is 8-10%, and the porosity at the edge is 5-7%;

[0120] Optionally, the average porosity of the intermediate layer can be any value between 5%, 6%, 7%, 8%, 9%, 10% or 5-10%, the porosity of the apex can be any value between 8%, 9%, 10% or 8-10%, and the porosity of the edge can be any value between 5%, 6%, 7% or 5-7%.

[0121] It is important to note that the vertex refers to the circular area centered on the highest point of the arched intermediate layer surface (i.e., the vertex), extending outwards at an angle of 10°-15° to the normal direction of the vertex. This area is the core stress concentration zone of the arched surface. The edge refers to the annular area near the outer perimeter of the arched surface, excluding the vertex area. From the edge towards the vertex, the angle between the area and the normal direction of the vertex gradually transitions from >15° to 10°, forming a gentle gradient transition from "edge to vertex". This is suitable for the gradient distribution requirement of the intermediate layer porosity (5-7% at the edge → 8-10% at the vertex).

[0122] It should also be noted that the porosity of the intermediate layer is distributed differently in different regions of the arch. The porosity at the apex is set at the upper limit (8-10%) to buffer the normal tensile stress, while the porosity at the edge is set at the lower limit (5-7%) to ensure the structural stiffness. This distribution reduces the strain concentration factor of the arch structure by 40% during thermal shock.

[0123] E. The mass ratio of the ytterbium oxide, the gadolinium oxide, and the yttrium oxide-modified zirconium oxide is 1-2:1-1.5:2-3;

[0124] Optionally, the mass ratio of ytterbium oxide, gadolinium oxide, and yttrium oxide modified zirconium oxide can be any value between 1:1:2, 1.5:1:2, 2:1:2, 1:1.5:2, 1:1.5:2.5, 1:1.5:3, or 1-2:1-1.5:2-3;

[0125] F. The thickness of the arched ceramic coating is 0.3mm-0.8mm;

[0126] Optionally, the thickness of the arched ceramic coating can be any value between 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm or 0.3mm-0.8mm;

[0127] G. The mass ratio of Y2O3 to nano-zirconia is 3-5:95-97.

[0128] Optionally, the mass ratio of Y2O3 to nano-zirconia can be any value between 3:97, 4:96, 5:95, or 3-5:95-97.

[0129] In some embodiments, the highly thermally shock resistant arched ceramic-coated part satisfies at least one of the following conditions:

[0130] A. The curvature difference between the arched alloy substrate and the arched ceramic coating is less than or equal to 2%;

[0131] Optionally, the curvature difference between the arched alloy substrate and the arched ceramic coating can be any value of 0.01%, 0.1%, 1%, 2%, or less than or equal to 2%.

[0132] It is important to note that the curvature matching error between the arched alloy substrate and the arched ceramic coating does not exceed ±2%. This double-arched synergistic structure allows the coating and substrate to deform synchronously during thermal shock, forming a good mechanical coupling. When the substrate undergoes slight deformation due to thermal shock, the coating can adjust synchronously with the arched surface of the substrate, reducing interfacial stress caused by inconsistent deformation.

[0133] B. The radius of curvature of the arched alloy substrate is 15-35 mm;

[0134] Optionally, the radius of curvature of the arched alloy substrate can be any value between 15mm, 20mm, 25mm, 30mm, 35mm or 15-35mm;

[0135] It is important to note that the radius of curvature determines the degree of curvature of the arched surface. A reasonable curvature can ensure that thermal stress is evenly distributed in a ring shape along the surface, avoiding linear stress concentration. When the radius of curvature of the arched alloy substrate is 15-35mm, this range can ensure that thermal stress is transformed into tangential compressive stress through the surface geometry, reducing the damage of normal tensile stress to the coating-substrate interface. In addition, the arched structure generates elastic deformation through curvature fine adjustment during thermal shock, absorbing some thermal stress. The radius of curvature is positively correlated with the deformation. A suitable radius can balance deformation energy and structural stiffness, avoiding excessive deformation that could lead to coating peeling.

[0136] When the radius of curvature is less than 15mm, it will cause intensified local stress concentration. Excessive curvature of the surface will form stress concentration zones at the apex and edges of the arch. During thermal shock, the normal tensile stress at these points will exceed the tensile strength of the coating, leading to early cracking of the coating. Furthermore, insufficient substrate rigidity will cause the stiffness of the alloy substrate in the thickness direction to decrease. During thermal shock, the substrate is prone to plastic deformation, disrupting the curvature match between the coating and the substrate, leading to coating peeling due to deformation mismatch. It will also cause damage to the coating thickness uniformity: a too-small radius of curvature will increase the difficulty of plasma spraying, resulting in coating thickness deviations exceeding ±3%, and locally thin areas are more likely to fail under thermal shock first. When the radius of curvature is greater than 35mm... When the radius of curvature is too large (mm), the stress dispersion effect is weakened. An excessively large radius of curvature makes the arch shape approach a plane, and thermal stress cannot be effectively dispersed through the curved surface geometry, returning to the stress distribution pattern of traditional planar coatings. It also causes uneven heat flow distribution. An excessively large radius of curvature will cause the heat flow to conduct along the arch surface to become longer, resulting in temperature gradient differences in local areas. The substrate will undergo additional deformation due to inconsistent thermal expansion and contraction, which will increase the risk of coating peeling. It will also cause a decrease in structural stability. Arch structures with high radii of curvature are prone to creep instability at high temperatures, especially the metal substrate, which has reduced endurance strength at 800-1000℃. Creep deformation may cause the coating to debond from the substrate.

[0137] Therefore, when the radius of curvature of the arched alloy substrate is 15-35mm, mechanical equilibrium will be achieved. This range allows the thermal stress dispersion efficiency to be optimally matched with the substrate stiffness.

[0138] C. The bonding strength between the arched alloy substrate and the arched ceramic coating is greater than 40 MPa;

[0139] Optionally, the bonding strength between the arched alloy substrate and the arched ceramic coating can be any value of 45 MPa, 50 MPa, 100 MPa, 200 MPa, 300 MPa, 400 MPa or greater than 40 MPa.

[0140] D. In the MCrAlYHfSi alloy, the mass content of Hf is 0.5-2% and the mass content of Si is 0.1-1%.

[0141] Optionally, in the MCrAlYHfSi alloy, the mass content of Hf can be any value between 0.5%, 1%, 1.5%, 2% or 0.5-2%, and the mass content of Si can be any value between 0.1%, 0.5%, 1% or 0.1-1%.

[0142] It is important to note that during thermal vibration, the arched surface experiences tangential compressive stress and normal tensile stress along the surface due to curvature changes. Stress concentration zones are easily formed at the apex and edges, and the curvature of the substrate and coating deforms in tandem. The thickness of the bottom layer accounts for 20%-30% of the thickness of the arched ceramic coating (0.06-0.24 mm), utilizing its high ductility to buffer the arched deformation of the substrate. The thickness of the middle layer accounts for 30%-40% of the thickness of the arched ceramic coating (0.09-0.32 mm) as a stress transition buffer zone. The top layer accounts for 30%-40% of the thickness of the arched ceramic coating (0.09-0.32 mm) and forms a crack-resistant protective layer on the arched surface. The thickness of the three layers is optimized according to the stress distribution gradient of the arched surface, and the thickness of the top layer at the apex can be increased by 5%-10% to resist tensile stress.

[0143] A second aspect of this application provides a method for preparing the aforementioned high thermal shock resistant arched ceramic coated part, comprising:

[0144] An arched alloy substrate is provided, and the arched alloy substrate is pretreated to obtain a pretreated substrate;

[0145] Using argon as the carrier gas, MCrAlYHfSi alloy powder was subjected to a first plasma spraying on the surface of the arched alloy substrate to obtain the bottom layer;

[0146] A second plasma spraying of nano-zirconia powder and Y2O3 is performed on the surface of the bottom layer to obtain an intermediate layer;

[0147] Ternary rare earth powder is subjected to a third plasma spraying on the surface of the intermediate layer to obtain a substrate with a top layer after spraying.

[0148] In a vacuum environment, the coated substrate is heated to obtain a highly thermally shock resistant arched ceramic coated part.

[0149] The ternary rare earth powder includes ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconium oxide powder.

[0150] In some embodiments, the method for preparing the highly thermally shock resistant arched ceramic coated part satisfies at least one of the following conditions:

[0151] A. The arched alloy substrate is prepared by isostatic pressing or mechanical cutting.

[0152] The isostatic pressing process includes: sequentially performing hot isostatic pressing and machining on the raw material of the arched alloy substrate;

[0153] The mechanical cutting process includes: cutting the alloy substrate using a cutting tool or a laser beam;

[0154] B. The pretreatment includes sandblasting roughening and cleaning;

[0155] The abrasive particle size for the sandblasting roughening is 80-120 mesh, and the sandblasting pressure is 0.3-0.5 MPa;

[0156] Optionally, the abrasive particle size for sandblasting roughening can be 80 mesh, 90 mesh, 100 mesh, 110 mesh, 120 mesh or any value between 80 and 120 mesh;

[0157] C. The deposited bottom layer, the intermediate layer and the top layer are cooled respectively, and the final temperature of the cooling is 80-120℃.

[0158] Optionally, the deposited bottom layer, intermediate layer and top layer can be cooled separately, and the final cooling temperature can be any value between 80℃, 90℃, 100℃, 110℃, 120℃ or 80-120℃.

[0159] It is important to note that during the spraying process, arched ceramic coatings are prone to localized heat accumulation (such as in the apex area), leading to concentrated thermal stress in the coating. Cooling to 80-120℃ can prevent the coating from overheating and cracking, while ensuring thermal expansion matching between layers (curvature error ≤ ±2%). Furthermore, the gradient change in the thermal expansion coefficient of the arched ceramic coating requires precise control of the interlayer temperature. If the previous layer is not sufficiently cooled, the high temperature during the spraying of the subsequent layer will degrade the properties of the previous layer material, affecting the stress buffering effect of the gradient structure.

[0160] In some embodiments, the method for preparing the highly thermally shock resistant arched ceramic coated part satisfies at least one of the following conditions:

[0161] A. The hot isostatic pressing process is performed at a pressure of 150-250 MPa, a temperature of 800-1000℃, and a holding time of 2-4 hours.

[0162] Optionally, the pressure for hot isostatic pressing can be any value between 150 MPa, 200 MPa, 250 MPa or 150-250 MPa, the temperature can be any value between 800℃, 900℃, 1000℃ or 800-1000℃, and the holding time can be any value between 2h, 3h, 4h or 2-4h.

[0163] B. In the mechanical cutting process, the cutting speed of the cutting tool is 5000-15000 r / min, and the feed speed is 500-3000 mm / min;

[0164] Optionally, the cutting speed of the cutting tool during the mechanical cutting process can be any value between 5000 r / min, 10000 r / min, 15000 r / min or 5000-15000 r / min, and the feed speed can be any value between 500 mm / min, 1000 mm / min, 2000 mm / min, 3000 mm / min or 500-3000 mm / min;

[0165] The laser beam has a power of 0.5-5kW and a cutting speed of 0.2-3m / min.

[0166] Optionally, the laser power of the laser beam can be any value between 0.5kW, 1kW, 3kW, 5kW or 0.5-5kW, and the cutting speed can be any value between 0.2m / min, 1m / min, 2m / min, 3m / min or 0.2-3m / min.

[0167] In some embodiments, the method for preparing the highly thermally shock resistant arched ceramic coated part satisfies at least one of the following conditions:

[0168] A. During the first plasma spraying process, the working gas includes hydrogen and argon, the flow rate of hydrogen is 5-8 L / min, the flow rate of argon is 40-50 L / min, the spraying power is 30-40 kW, the powder feeding speed is 15-25 g / min, the spraying distance is 80-100 mm, the flow rate of the carrier gas is 8-10 L / min, and the residence time of the MCrAlYHfSi alloy powder in the flame is 0.5-1 ms;

[0169] Optionally, during the first plasma spraying process, the flow rate of hydrogen can be any value between 5 L / min, 6 L / min, 7 L / min, 8 L / min, or 5-8 L / min; the flow rate of argon can be any value between 40 L / min, 45 L / min, 50 L / min, or 40-50 L / min; the spraying power can be any value between 30 kW, 35 kW, 40 kW, or 30-40 kW; the powder feeding speed can be any value between 15 g / min, 20 g / min, 25 g / min, or 15-25 g / min; the spraying distance can be any value between 80 mm, 90 mm, 100 mm, or 80-100 mm; and the flow rate of the carrier gas can be any value between 8 L / min, 9 L / min, 10 L / min, or 8-10 L / min. The residence time of the MCrAlYHfSi alloy powder in the flame can be any value between 0.5 ms, 0.7 ms, 1 ms, or 0.5-1 ms.

[0170] It is important to note that the radius of curvature (15-35mm) of the arched alloy substrate determines the precise control of the spraying distance and powder feeding speed, ensuring that the coating is deposited uniformly along the curved surface (thickness error ±3%).

[0171] B. During the second plasma spraying process, the working gas includes hydrogen and argon, the flow rate of hydrogen is 6-9 L / min, the flow rate of argon is 45-55 L / min, the spraying power is 35-45 kW, the powder feeding speed is 12-18 g / min, the spraying distance is 90-110 mm, the flow rate of carrier gas is 8-10 L / min, and the flame temperature is 12000-14000℃;

[0172] Optionally, during the second plasma spraying process, the flow rate of hydrogen can be any value between 6 L / min, 7 L / min, 8 L / min, 9 L / min, or 6-9 L / min; the flow rate of argon can be any value between 45 L / min, 50 L / min, 55 L / min, or 45-55 L / min; the spraying power can be any value between 35 kW, 40 kW, 45 kW, or 35-45 kW; the powder feeding speed can be any value between 12 g / min, 15 g / min, 18 g / min, or 12-18 g / min; the spraying distance can be any value between 90 mm, 100 mm, 110 mm, or 90-110 mm; the flow rate of the carrier gas can be any value between 8 L / min, 9 L / min, 10 L / min, or 8-10 L / min; and the flame temperature can be any value between 12000℃, 13000℃, 14000℃, or 12000-14000℃.

[0173] C. During the third plasma spraying process, the working gas includes hydrogen and argon, the flow rate of hydrogen is 8-12 L / min, the flow rate of argon is 50-60 L / min, the spraying power is 40-50 kW, the flame temperature is 14000-16000℃, the powder feeding speed is 15-20 g / min, the carrier gas flow rate is 10-12 L / min, and the spraying distance is 80-100 mm;

[0174] Optionally, during the third plasma spraying process, the flow rate of hydrogen can be any value between 8 L / min, 10 L / min, 12 L / min, or 8-12 L / min; the flow rate of argon can be any value between 40 L / min, 45 L / min, 50 L / min, or 40-50 L / min; the spraying power can be any value between 40 kW, 45 kW, 50 kW, or 40-50 kW; the flame temperature can be any value between 14000℃, 15000℃, 16000℃, or 14000-16000℃; the powder feeding rate can be any value between 15 g / min, 18 g / min, 20 g / min, or 18-20 g / min; the flow rate of the carrier gas can be any value between 10 L / min, 11 L / min, 12 L / min, or 10-12 L / min; and the spraying distance can be any value between 80 mm, 90 mm, 100 mm, or 80-100 mm.

[0175] D. The MCrAlYHfSi alloy powder has a particle size of 50-100 μm and a loose packing density of 3.5-4.0 g / cm³. 3 ;

[0176] Optionally, the particle size of the MCrAlYHfSi alloy powder can be 50μm, 75μm, 100μm, or any value between 50-100μm, and the loose packing density can be 3.5g / cm³. 3 3.7g / cm 3 4.0g / cm 3 Or 3.5-4.0 g / cm³ 3 Any value between;

[0177] E. The nano-zirconia powder has a particle size of 50-80 μm and a loose packing density of 2.0-2.5 g / cm³. 3 ;

[0178] Optionally, the particle size of the nano-zirconia powder can be any value between 50μm, 60μm, 70μm, 80μm, or 50-80μm, and the loose packing density can be 2g / cm³. 3 2.3g / cm 32.5g / cm 3 Or 2.0-2.5 g / cm³ 3 Any value between;

[0179] F. The particle size of the ternary rare earth powder is 50-80 nm, and the loose packing density is 2.8-3.2 g / cm³. 3 .

[0180] Optionally, the particle size of the ternary rare earth powder can be any value between 50nm, 60nm, 70nm, 80nm, or 50-80nm, and the loose packing density can be 2.8g / cm³. 3 3g / cm 3 3.2g / cm 3 Or 2.8-3.2 g / cm³ 3 Any value between.

[0181] In some embodiments, the heating rate of the heating treatment is 5-10℃ / min, the final temperature is 800-1000℃, the holding time is 2-4h, and the cooling rate is 3-5℃ / min.

[0182] Optionally, the heating rate can be any value between 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, 10℃ / min or 5-10℃ / min, the endpoint temperature can be any value between 800℃, 900℃, 1000℃ or 800-1000℃, the holding time can be any value between 2h, 3h, 4h or 2-4h, and the cooling rate can be any value between 3℃ / min, 4℃ / min, 5℃ / min or 3-5℃ / min.

[0183] It should be noted that heat treatment in the range of 800-1000℃ will cause the arched alloy substrate and the arched ceramic coating to synergistically sinter, forming an interfacial diffusion layer with a bonding strength >40MPa.

[0184] It should be noted that the high thermal shock resistant arched ceramic coating parts provided in this application exhibit no peeling after ≥30 cycles of thermal shock cycling from 1150℃ to room temperature.

[0185] It should also be noted that this application employs a collaborative design across three dimensions: curvature, thermal expansion, and elastic modulus.

[0186] 1. Geometric dimension: The ratio of the arch curvature radius (15-35mm) to the coating thickness (0.3-0.8mm) ensures that the thermal stress attenuation gradient along the curved surface matches the material gradient;

[0187] 2. Material dimension: The high expansion coefficient of the bottom layer and its curvature compatibility with the substrate, and the low expansion coefficient of the top layer and the compressive stress state of the arched surface form a causal relationship;

[0188] 3. Process dimension: The fabrication accuracy of the arch structure (±2% curvature error) and the online monitoring of the coating spraying form a manufacturing closed loop, ensuring the consistency of the geometry-material relationship;

[0189] This multi-dimensional correlation breaks through the limitations of existing technologies that separate layer composition from structural morphology, forming a design of "structural guidance of stress distribution - material gradient adaptation to structural requirements", which solves the problem of coating peeling caused by deformation of high-temperature alloy substrates during thermal shock.

[0190] A third aspect of this application provides an aircraft engine including the aforementioned high thermal shock resistant arched ceramic coated part.

[0191] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0192] Example 1

[0193] This embodiment provides a high thermal shock resistant arched ceramic coating part, comprising an arched alloy substrate and an arched ceramic coating disposed on the surface of the arched alloy substrate; wherein the arched alloy substrate is GH4169, with an elastic modulus of 160 GPa and a coefficient of thermal expansion of 12.8 × 10⁻⁶. -6 / ℃.

[0194] The arched ceramic coating has a thickness of 0.5 mm and consists of a bottom layer, an intermediate layer, and a top layer stacked sequentially. The bottom layer is connected to the arched alloy substrate, and its thickness accounts for 25% of the total thickness of the arched ceramic coating. The intermediate layer accounts for 35% of the total thickness of the arched ceramic coating, and the top layer accounts for 40% of the total thickness of the arched ceramic coating. The bottom layer is an MCrAlYHfSi alloy, where M represents Ni and Co. The MCrAlYHfSi alloy contains 40% Ni, 20% Co, 18% Cr, 10% Al, 0.3% Y, 1% Hf, and 0.5% Si. The intermediate layer consists of nano-zirconia and Y2O3 (the mass ratio of Y2O3 to nano-zirconia is 4:96). The top layer consists of ytterbium oxide, gadolinium oxide, and yttrium-modified zirconia (the mass ratio of ytterbium oxide, gadolinium oxide, and yttrium-modified zirconia powder is 1.5:1.2:2.5).

[0195] The elastic modulus of the bottom layer, the middle layer, and the top layer increases sequentially, while the coefficient of thermal expansion decreases sequentially. The coefficient of thermal expansion of the bottom layer is 13.5 × 10⁻⁶. -6 / ℃, elastic modulus 140Gpa; the coefficient of thermal expansion of the intermediate layer is 10.5×10 -6 / ℃, elastic modulus is 200Gpa; coefficient of thermal expansion of surface layer is 7×10 -6 / ℃, elastic modulus 260Gpa.

[0196] The curvature of the arched alloy substrate is 0.033 mm. -1 The curvature of the arched ceramic coating is 0.0333 mm. -1 The curvature difference between the arched alloy substrate and the arched ceramic coating is 1%, and the radius of curvature of the arched alloy substrate is 30 mm.

[0197] The second aspect of this embodiment provides a method for preparing a highly thermally shock resistant arched ceramic coated part, the specific preparation method including:

[0198] S1: Fix the bulk metal substrate to the processing equipment, and control the cutting tool (the tool is a carbide end mill, the cutting speed is 10000r / min, and the feed rate is 1500mm / min) through the CNC machining system to form an arched alloy substrate;

[0199] S2: The arched alloy substrate is roughened by sandblasting with brown corundum abrasive with a particle size of 100 mesh and a sandblasting pressure of 0.4 MPa. Then, it is ultrasonically cleaned in ethanol solution for 20 min to obtain the pretreated substrate.

[0200] S3: Utilizes plasma spraying technology to coat particles with a diameter of 75μm and a bulk density of 3.8g / cm³. 3 MCrAlYHfSi alloy powder was applied to the surface of the pretreated substrate. The power was 35kW, and the working gas was argon (main gas, flow rate 45L / min) + hydrogen (auxiliary gas, flow rate 6L / min) to form a high-temperature plasma flame (temperature 11000℃). The powder feeding speed was 12g / min, the carrier gas (argon) flow rate was 9L / min, the powder residence time in the flame was 0.8ms, and the spraying distance was dynamically adjusted and controlled within 90mm. After spraying, the interlayer was cooled to 100℃ to obtain the bottom layer.

[0201] S4: Using plasma spraying technology, a mixture of nano-zirconia powder (50nm particle size, agglomerated into 60μm sprayable particles) and Y2O3 powder (loose packing density 2.2g / cm³) is applied. 3The coating is placed on the bottom surface, with a power of 40kW and working gas: argon (main gas, flow rate of 50L / min) + hydrogen (auxiliary gas, flow rate of 7L / min) to form a high-temperature plasma flame (temperature of 13000℃); the powder feeding speed is 15g / min, the carrier gas (argon) flow rate is 10L / min, the spraying distance is dynamically adjusted and controlled within 100mm, and the interlayer is cooled to 100℃ after spraying to obtain an intermediate layer with an average porosity of 7%, a porosity of 9% at the apex, and a porosity of 6% at the edge;

[0202] S5: Utilizing plasma spraying technology, a mixed powder of ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconium oxide (particle size 65μm) with a loose packing density of 3.0 g / cm³ is applied. 3 The yttrium oxide-modified zirconium oxide powder is placed on the surface of the intermediate layer. The preparation method of the yttrium oxide-modified zirconium oxide powder is as follows: using the sol-gel method, ZrOCl2... 8H2O and Y(NO3)3 6H2O was dissolved in an ethanol-water solution at a molar ratio of 92:8. Citric acid (chelating agent) was added, and the mixture was stirred at 80°C for 3 hours to form a sol. The sol was dried at 120°C for 8 hours to obtain a dry gel. The gel was calcined at 800°C for 2 hours, crushed, and sieved to obtain the desired coating powder. The plasma spraying power was 45kW, and the working gas was argon (main gas, flow rate 55L / min) + hydrogen (auxiliary gas, flow rate 10L / min) to form a high-temperature plasma flame (temperature 15000°C). The powder feeding speed was 18g / min, the carrier gas (argon) flow rate was 11L / min, and the spraying distance was dynamically adjusted and controlled within 90mm. After spraying, the interlayer was cooled to 100°C to obtain the surface layer.

[0203] S6: Under vacuum conditions, the sprayed substrate obtained in step S5 is heated. The heating rate is 8℃ / min, the final temperature is 900℃, the holding time is 3h, and the cooling rate is 4℃ / min to obtain a high thermal shock resistant arched ceramic coating part.

[0204] The actual product of this highly thermally shock resistant arched ceramic-coated part is shown below. Figure 1 As shown.

[0205] Example 2

[0206] The difference from Example 1 is that the thickness of the bottom layer accounts for 20% of the thickness of the arched ceramic coating; the thickness of the middle layer accounts for 40% of the thickness of the arched ceramic coating; and the thickness of the bottom layer accounts for 40% of the thickness of the arched ceramic coating.

[0207] The elastic modulus of the bottom layer, the middle layer, and the top layer increases sequentially, while the coefficient of thermal expansion decreases sequentially. The coefficient of thermal expansion of the bottom layer is 12.5 × 10⁻⁶. -6 / ℃, elastic modulus 135Gpa; coefficient of thermal expansion of the intermediate layer is 9.5×10-6 / ℃, elastic modulus is 185Gpa; the coefficient of thermal expansion of the surface layer is 6.5×10. -6 / ℃, elastic modulus 255Gpa.

[0208] Example 3

[0209] The difference from Example 1 is as follows: M in the MCrAlYHfSi alloy is Ni and Co; the composition of the MCrAlYHfSi alloy is 38% Ni, 22% Co, 18.5% Cr, 8.5% Al, 0.4% Y, 1.5% Hf, and 0.8% Si; the mass ratio of ytterbium oxide, gadolinium oxide, and yttrium oxide-modified zirconium oxide is 1.8:1.4:2.8; and the mass ratio of Y2O3 and nano-zirconia is 4.5:95.5.

[0210] The elastic modulus of the bottom layer, middle layer, and top layer increases sequentially, while the coefficient of thermal expansion decreases sequentially. The coefficient of thermal expansion of the bottom layer is 14 × 10⁻⁶. -6 / ℃, elastic modulus 142Gpa; coefficient of thermal expansion of the intermediate layer is 11×10. -6 / ℃, elastic modulus is 210Gpa; the coefficient of thermal expansion of the surface layer is 7.2×10 -6 / ℃, elastic modulus 260Gpa.

[0211] Comparative Example 1

[0212] The difference from Example 1 is that no underlying layer is set.

[0213] Comparative Example 2

[0214] The difference from Example 1 is that no intermediate layer is set.

[0215] Comparative Example 3

[0216] The difference from Example 1 is that no surface layer is provided.

[0217] Comparative Example 4

[0218] The difference from Example 1 is the order in which the bottom layer and the top layer are replaced.

[0219] Comparative Example 5

[0220] The difference from Example 1 is that only the bottom layer is set.

[0221] Comparative Example 6

[0222] The difference from Example 1 is that only an intermediate layer is set.

[0223] Comparative Example 7

[0224] The difference from Example 1 is that only the surface layer is provided.

[0225] Comparative Example 8

[0226] The difference from Example 1 is that the alloy substrate and coating are rectangular structures (planar structures) with equal sides.

[0227] The ceramic-coated parts provided in the above embodiments and comparative examples were subjected to performance tests, and the test results are shown in Table 1.

[0228] Among them, the residual tensile stress at the interface after thermal shock (MPa): the tensile stress value remaining at the interface after thermal shock cycling at 1150℃ to room temperature;

[0229] 1150℃-room temperature thermal shock cycle life (cycles): The maximum number of thermal shock cycles without cracking or peeling of the coating;

[0230] Tensile bond strength (MPa): The maximum bearing capacity of the interface against separation in a static tensile test;

[0231] CMAS erosion depth at 1350℃ (μm / 100h): Simulates high-temperature calcium magnesium aluminum silicate molten salt erosion to test the surface layer's resistance to penetration.

[0232] Table 1 Performance Tests

[0233]

[0234] analyze:

[0235] As can be seen from the above results, and from the test results, Examples 1-3, due to their "arched structure + complete gradient coating + reasonable composition design", have significantly better performance than the comparative examples. Comparative Examples 1-7, due to the absence of key functional layers (e.g., Comparative Example 1 lacks a bottom layer, Comparative Example 2 lacks an intermediate layer) or the layer sequence is reversed (Comparative Example 4), resulted in a sharp increase in residual tensile stress at the interface to 55-95 MPa after thermal shock (severe stress concentration), a cycle life of only 3-20 cycles, and a bonding strength of 12-35 MPa. Moreover, most of them lacked a complete protective layer, leading to a CMAS erosion depth exceeding 8 μm / 100h. Comparative Example 8, due to its planar structure (without arched stress dispersion), although the coating was complete, showed significantly worse residual tensile stress at the interface (75 MPa), cycle life (25 cycles), and CMAS erosion depth (7.0 μm / 100h) after thermal shock compared to Examples 1-3. This further proves the necessity and superiority of the design logic of "arched structure guiding stress distribution + gradient coating adapting stress + composition optimization strengthening performance" in the document. Furthermore, each functional layer (bottom layer bonding buffer, intermediate layer transition coordination, and surface layer protection and corrosion resistance) and the arched structure are indispensable.

[0236] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0237] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A high thermal shock resistant arcuate ceramic coated part, characterized by, The arch-shaped ceramic coating is provided on the surface of the arch-shaped alloy substrate. The arch-shaped ceramic coating comprises a bottom layer, an intermediate layer and a surface layer which are sequentially arranged, and the bottom layer is adjacent to the arch-shaped alloy substrate. The arch-shaped alloy substrate comprises a nickel-based superalloy. The bottom layer comprises an MCrAlYHfSi alloy, wherein M comprises Ni and Co. The intermediate layer comprises nano-zirconium oxide and Y2O3. The surface layer comprises ytterbium oxide, gadolinium oxide and yttrium oxide modified zirconia. The elastic modulus of the bottom layer, the intermediate layer and the surface layer is sequentially increased, and the thermal expansion coefficient is sequentially decreased.

2. The high thermal shock resistant, arcuate ceramic coated part of claim 1, wherein, At least one of the following conditions is met: A. the bottom layer has a coefficient of thermal expansion of 12 x 10 -6 / °C - 15 x 10 -6 / °C; B. the intermediate layer has a coefficient of thermal expansion of 9 x 10 -6 / °C - 12 x 10 -6 / °C; C. the face layer has a coefficient of thermal expansion of 6 x 10 -6 / °C to 8 x 10 -6 / °C; D. the coefficient of thermal expansion of the arched alloy substrate is 11 x 10 -6 / °C - 15 x 10 -6 / °C; E. The elastic modulus of the bottom layer is ≤ 150 GPa; F. The elastic modulus of the intermediate layer is 180-220 GPa; G. The elastic modulus of the surface layer is ≥ 250 GPa; H. The elastic modulus of the arch-shaped alloy substrate is 140-180 GPa.

3. The high thermal shock resistant arcuate ceramic coated part of claim 1, wherein, At least one of the following conditions is met: A. The thickness of the bottom layer accounts for 20%-30% of the arch-shaped ceramic coating; B. The thickness of the intermediate layer accounts for 30%-40% of the arch-shaped ceramic coating; C. The thickness of the surface layer accounts for 30%-40% of the arch-shaped ceramic coating; D. The average porosity of the intermediate layer is 5-10%, the porosity of the vertex is 8-10%, and the porosity of the edge is 5-7%; E. The mass ratio of the ytterbium oxide, the gadolinium oxide and the yttrium oxide modified zirconia is 1-2:1-1.5:2-3; F. The thickness of the arch-shaped ceramic coating is 0.3mm-0.8mm; G. The mass ratio of the Y2O3 and the nano-zirconium oxide is 3-5:95-97.

4. The high thermal shock resistant, arcuate ceramic coated part of claim 1, wherein, At least one of the following conditions is met: A. The curvature difference between the arch-shaped alloy substrate and the arch-shaped ceramic coating is less than or equal to 2%; B. The curvature radius of the arch-shaped alloy substrate is 15-35mm; C. The bonding strength between the arch-shaped alloy substrate and the arch-shaped ceramic coating is greater than 40MPa; D. In the MCrAlYHfSi alloy, based on the total mass of 100%, it comprises: 35-45% Ni, 15-25% Co, 15-20% Cr, 8-12% Al, 0.1-0.5% Y, 0.5-2% Hf, 0.1-1% Si.

5. A method of producing a high thermal shock resistant dome-shaped ceramic coated part according to any one of claims 1 to 4, characterized in that, The method comprises: providing an arch-shaped alloy substrate, and pretreating the arch-shaped alloy substrate to obtain a pretreated substrate; using argon as a carrier gas, performing first plasma spraying of MCrAlYHfSi alloy powder on the surface of the arch-shaped alloy substrate to obtain a bottom layer; performing second plasma spraying of nano-zirconium oxide powder and Y2O3 on the surface of the bottom layer to obtain an intermediate layer; performing third plasma spraying of ternary rare earth powder on the surface of the intermediate layer to obtain a sprayed substrate provided with a surface layer; performing heating treatment on the sprayed substrate in a vacuum environment to obtain a high-thermal-shock arch-shaped ceramic coating part; The ternary rare earth powder comprises ytterbium oxide, gadolinium oxide and yttrium oxide modified zirconia powder.

6. The method of making a high thermal shock resistant, arcuate ceramic coated part according to claim 5, wherein, At least one of the following conditions is met: A. The arched alloy base material is prepared by an isostatic pressing process or a mechanical cutting process; The isostatic pressing process comprises: sequentially performing hot isostatic pressing and mechanical processing on the raw material of the arched alloy base material; The mechanical cutting process comprises: cutting the alloy base material using a cutting tool or a laser beam; B. The pretreatment comprises sand blasting and cleaning; The abrasive particle size for the sand blasting is 80-120 mesh, and the sand blasting pressure is 0.3-0.5 MPa; C. The bottom layer, the intermediate layer and the surface layer obtained by deposition are cooled respectively, and the end point temperature of the cooling is 80-120℃.

7. The method of making a high thermal shock resistant, arcuate ceramic coated part according to claim 6, wherein, At least one of the following conditions is met: A. The pressure of the hot isostatic pressing is 150-250 MPa, the temperature is 800-1000℃, and the holding time is 2-4h; B. The cutting tool has a cutting rotation speed of 5000-15000 r / min and a feeding speed of 500-3000 mm / min during the mechanical cutting process; The laser beam has a laser power of 0.5-5 kW and a cutting speed of 0.2-3 m / min.

8. The method of making a high thermal shock resistant, arcuate ceramic coated part according to claim 5, wherein, At least one of the following conditions is met: A. During the first plasma spraying process, the working gas comprises hydrogen and argon, the flow rate of the hydrogen is 5-8 L / min, the flow rate of the argon is 40-50 L / min, the spraying power is 30-40 kW, the powder feeding speed is 15-25 g / min, the spraying distance is 80-100 mm, the flow rate of the carrier gas is 8-10 L / min, and the MCralYHfSi alloy powder stays in the flame for 0.5-1 ms; B. During the second plasma spraying process, the working gas comprises hydrogen and argon, the flow rate of the hydrogen is 6-9 L / min, the flow rate of the argon is 45-55 L / min, the spraying power is 35-45 kW, the powder feeding speed is 12-18 g / min, the spraying distance is 90-110 mm, the flow rate of the carrier gas is 8-10 L / min, and the flame temperature is 12000-14000℃; C. During the third plasma spraying process, the working gas comprises hydrogen and argon, the flow rate of the hydrogen is 8-12 L / min, the flow rate of the argon is 50-60 L / min, the spraying power is 40-50 kW, the flame temperature is 14000-16000℃, the powder feeding speed is 15-20 g / min, the flow rate of the carrier gas is 10-12 L / min, and the spraying distance is 80-100 mm; D. The MCrAlYHfSi alloy powder has a particle size of 50-100 μm and a loose bulk density of 3.5-4.0 g / cm3 3 ; E. The particle size of the nano zirconium oxide powder is 50-80 μm, and the loose bulk density is 2.0-2.5 g / cm 3 ; F. The particle size of the ternary rare earth powder is 50-80 nm, and the loose bulk density is 2.8-3.2 g / cm 3 .

9. The method of making a high thermal shock resistant arcuate ceramic coated part according to any one of claims 5-8, wherein, The heating rate of the heating treatment is 5-10℃ / min, the end point temperature is 800-1000℃, the holding time is 2-4h, and the cooling rate is 3-5℃ / min.

10. An aeroengine characterised in that, A high-thermal-shock-resistant arched ceramic coating part comprising the arched ceramic coating part of any one of claims 1-4.

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