Temperature sensing and thermal barrier integrated a2b2o7 ceramic material, preparation method and application thereof

Abstract

This application provides an integrated temperature-sensitive thermal barrier protection A2B2O7 ceramic material, its preparation method, and its application, which possesses A... 2‑ a The B2O7:aX material has a general structural formula and a crystal structure that is defective fluorite, pyrochlore, or a mixed two-phase structure. Doping with two or more types of luminescent ions allows for temperature measurement based on the fluorescence intensity ratio of non-thermally coupled energy levels, overcoming the limitations of relative sensitivity in traditional thermally coupled energy level temperature measurement. It utilizes the anti-thermal quenching or low-thermal quenching effects of the luminescent ions to extend the upper limit of temperature measurement, and the different temperature response characteristics of different luminescent ions enhance relative sensitivity. This material can be directly used to prepare a dual-function integrated coating for temperature sensing and thermal barrier protection, eliminating the difficulties of externally mounted sensors, avoiding damage to the coating integrity, and simplifying the complex layout of functional layers. It achieves the integration of thermal barrier protection and high-temperature sensing functions, providing a forward-looking solution for the safety assurance and condition monitoring of components operating in extreme high-temperature environments such as aero-engines and gas turbines.

Description

Technical Field

[0001] This application belongs to the fields of thermal barrier materials and optical temperature sensing technology, and particularly relates to an integrated A2B2O7 ceramic material for temperature sensing and thermal barrier protection, its preparation method and application. Background Technology

[0002] The ultra-high temperature operating environment poses a significant challenge to the long-term use of hot-end components such as turbine blades in aero-engines. To address this challenge, thermal barrier materials are typically coated onto the blade surface to reduce surface temperature and extend its service life. Simultaneously, real-time three-dimensional temperature monitoring of hot-end components can prevent a series of catastrophic consequences caused by uneven temperature distribution and large thermal gradients. Traditional thermocouple contact temperature measurement cannot achieve intelligent three-dimensional temperature monitoring of blades, and its invasive installation increases blade weight and the risk of detachment. Fluorescent thermometry has attracted considerable attention due to its non-contact nature, fast response speed, and strong anti-interference capabilities, and its application to the temperature measurement of thermal barrier coatings on aero-engine blades shows great promise.

[0003] Patent GB2595866A proposes a material that uses a high-temperature phase transition to permanently alter luminescence properties, thus inferring temperature. This material can be sprayed onto a thermal barrier coating for temperature measurement; however, it can only record the highest historical temperature and cannot provide real-time monitoring. Patent GB2439389A achieves thermal barrier protection and temperature monitoring through a multi-layered structure of a fluorescent thermometric layer and a thermal barrier coating. Specifically, YSZ material serves as the thermal protection layer, while YAG-doped rare-earth luminescent material acts as the luminescent thermometric layer. However, the incompatibility between the different materials in the multi-layered structure makes it prone to detachment and failure. To avoid this multi-layered design, US20090202864A1 integrates thermal barrier protection and temperature measurement functions by adding luminescent YAG particles to the YSZ thermal barrier coating material using multi-phase composite technology. To further avoid compatibility issues between multiple materials, the patent with publication number US20230175139A1 directly co-doped rare earth elements Er and Eu into YSZ material to achieve temperature measurement. The trace amount of rare earth element doping did not change the thermal barrier performance of YSZ and could achieve real-time temperature monitoring.

[0004] However, as the operating temperature of turbine blades continues to rise, the development of integrated temperature sensing and thermal barrier protection materials has been limited by both thermal barrier and temperature measurement functions. Regarding the thermal barrier, the commonly used main material, YSZ, suffers from high-temperature phase transitions that cause volume expansion leading to detachment and failure, and its resistance to sintering at high temperatures deteriorates, no longer meeting requirements. In terms of temperature measurement, the thermal quenching behavior of rare-earth luminescence results in a low upper limit for temperature measurement, and the high-temperature temperature measurement sensitivity based on thermally coupled energy levels has an insurmountable theoretical upper limit, preventing the realization of three-dimensional real-time temperature detection for turbine blades.

[0005] A2B2O7 material possesses low thermal conductivity, excellent phase stability, good sintering resistance, and high hardness, making it a promising thermal barrier material. Patents CN102515717B and CN119118687A, respectively, have both modified A2B2O7 material to achieve relatively superior thermal barrier properties. However, neither patent investigated the luminescence characteristics or temperature sensing performance of this material as a luminescent matrix material; therefore, it remains unsuitable for use as an integrated temperature-sensing and thermal barrier protection material.

[0006] In summary, studying both the thermal barrier properties and the luminescent thermometric properties of A2B2O7 materials simultaneously is the preferred approach for developing novel materials that integrate temperature sensing and thermal barrier protection. Summary of the Invention

[0007] This application is made in view of the above-mentioned issues, and its purpose is to provide an A2B2O7 ceramic material with integrated temperature sensing and thermal barrier protection functions, as well as its preparation method and application.

[0008] The first aspect of this application provides an integrated A2B2O7 ceramic material for temperature sensing and thermal barrier protection. The material is obtained by doping the thermal barrier material A2B2O7 with rare earth ions, and its crystal structure can be defective fluorite type, pyrochlore type or mixed two-phase, thereby obtaining a material with light-emitting temperature sensing function and thermal barrier protection function.

[0009] In any embodiment, the general chemical formula of the material is A. 2-a B2O7:aX, wherein element A includes at least one of La, Y, Lu, Gd, Sc, and Yb, element B includes at least one of Zr, Hf, Sn, and Ti, and X is at least two doped luminescent ions, which can be rare earth ions, transition metal ions, other main group metal ions, or combinations thereof.

[0010] In any embodiment, the doped luminescent ions can produce obvious light emission after entering the crystal lattice. The excitation spectra of different doped luminescent ions have overlapping regions, can be excited by a common excitation wavelength, and the light emission has temperature-dependent characteristics.

[0011] In any embodiment, the thermal conductivity of the selected A2B2O7 material is ≤2.8 W·m. -1 ·K -1 Coefficient of thermal expansion ≥ 8.5 10 -6 K -1 Fracture toughness ≥ 0.75 MPa·m 1 / 2 Vickers hardness ≥ 8.5 GPa.

[0012] In any embodiment, the main emission peaks of the two or more doped luminescent ions do not overlap, and the energy level difference between the luminescent ions is ≥2000 cm⁻¹. -1 This method can be used for thermometry based on the fluorescence intensity ratio of non-thermally coupled energy levels, overcoming the limitations of relative sensitivity in traditional thermally coupled energy level thermometry. The luminescent ions possess different thermal quenching characteristics, which can extend the upper limit of temperature measurement (≥800K) and the relative sensitivity (≥0.3%K). -1 ).

[0013] Secondly, this invention provides a method for preparing an integrated temperature-sensitive thermal barrier protection A2B2O7 ceramic material, comprising the following steps: S1. Weigh at least one high-purity (≥99.99%) element A oxide raw material, at least one high-purity (≥99.99%) element B oxide raw material, and at least two luminescent ion oxide raw materials according to the stoichiometric ratio. At the same time, add dispersant, sintering aid, ball milling dispersion medium, and ball milling pellets in a certain proportion. Transfer all raw materials to a ball milling jar and ball mill them at a rotation speed of 200-500 r / min for 28-45 h using an all-round planetary ball mill. S2, After ball milling, remove the slurry and dry it in an oven at 80-150℃ for 12-20 hours; then place the dried powder in an agate mortar and grind it for 30-45 minutes, and then sieve it through a 150-300 mesh sieve to obtain fine powder. S3 uses a tableting mold to dry press the powder into shape. After pressing, it is placed in a corundum boat and the glue is removed in a muffle furnace. After being taken out and sealed, it is subjected to isotropic high pressure by a cold isostatic press to achieve uniform densification. S4. The green body is placed in a vacuum pulse Joule heating sintering furnace for high-temperature rapid sintering to obtain an integrated A2B2O7 ceramic material with temperature-sensitive thermal barrier protection.

[0014] In one embodiment, the oxide of element A is lanthanum oxide, yttrium oxide, scandium oxide, gadolinium oxide, ytterbium oxide, or lutetium oxide; the oxide of element B is zirconium oxide, hafnium oxide, titanium oxide, or tin oxide; and the luminescent ion oxide is a rare earth ion, a transition metal ion, or an oxide of another main group metal ion.

[0015] In one embodiment, the dispersant is ammonium citrate (C6H4O). 17 The addition ratio of N3O7 is 0.1-5% of the total mass of the raw materials; the sintering aid is tetraethyl orthosilicate (Si(OC2H5)4), and the addition ratio is 0.5-5% of the total mass of the raw materials; the ball milling dispersion medium is ethanol or water, and its mass ratio with the total mass of the raw materials is 0.7-1.2:1; the ball milling machine is an agate ball milling machine or a zirconia ball milling machine, and the total mass ratio of the ball milling machine to the total mass of the raw materials is 9-18:1.

[0016] In one embodiment, the ball milling particles are a mixture of different sizes, with diameters of 4-8 mm and 1-3 mm, respectively.

[0017] In one embodiment, the dry pressing pressure is 200-700 MPa, and the holding time is 2-5 min; the glue discharge temperature is 500-800℃, and the glue discharge time is 5-10 h; the cold isostatic press pressure is 200-300 GPa, and the holding time is 100-200 s.

[0018] In one embodiment, the vacuum pulse Joule heating sintering furnace heats the temperature from room temperature to 1550-1850°C in 2-5 seconds, and the sintering time is 20-45 seconds.

[0019] Thirdly, this invention provides a temperature measurement application of an integrated temperature-sensing thermal barrier protection A2B2O7 ceramic material in aero-engine turbine blades and related hot-end components, realizing three-dimensional real-time temperature measurement of turbine blades. The advantages and beneficial effects of this invention compared to the prior art are as follows: This invention extends the mainstream thermal barrier coating material A2B2O7 to high-temperature temperature measurement applications, creating an integrated A2B2O7 ceramic material with both temperature sensing and thermal barrier functions. It proposes a single-layer structure design that combines ultra-high temperature sensing and excellent thermal barrier performance, simplifying the traditional multi-layer structure, reducing the weight of the blades, and solving the incompatibility problem between the traditional contact temperature measurement functional layer and the thermal barrier coating.

[0020] The material of this invention has A 2-a B2O7:aX exhibits a general structural formula and a defective fluorite, pyrochlore, or mixed two-phase crystal structure, demonstrating superior thermal barrier protection performance. Furthermore, the addition of two or more luminescent ions allows for temperature measurement based on the fluorescence intensity ratio of non-thermally coupled energy levels, overcoming the limitations of relative sensitivity in traditional thermally coupled energy level temperature measurement. This is achieved by utilizing the anti-thermal quenching or low-thermal quenching effects of the luminescent ions to extend the upper limit of temperature measurement, and by enhancing relative sensitivity based on the different temperature response characteristics of different luminescent ions. Finally, its application to turbine blades successfully enabled three-dimensional dynamic high-temperature imaging and real-time temperature monitoring of the turbine blade surface. The material presented in this application can be directly used to prepare a dual-function integrated coating for thermal barrier protection and temperature sensing. Compared to the existing "thermal barrier coating" + "external thin-film thermocouple temperature sensor" approach, this eliminates the difficulties of external sensor attachment, avoids damage to the coating integrity, simplifies the complex layout of functional layers, and integrates thermal barrier protection and high-temperature sensing functions. This provides a forward-looking solution for the safety assurance and condition monitoring of components operating in extreme high-temperature environments, such as aero-engines and gas turbines.

[0021] This invention uses multiple luminescent ions as luminescent centers in an A2B2O7 matrix, among which Tm was discovered.3+ Based on [high temperature] 1 G4; 3 F4]→[ 1 D2; 3 A novel mechanism for reverse thermal quenching is achieved through the self-cross-relaxation process of the H6 channel. By utilizing the different temperature response characteristics of different luminescent centers at high temperatures, a thermometry based on the fluorescence intensity ratio of non-thermally coupled energy levels was designed, achieving a relative sensitivity ≥0.3%K in the high-temperature region. -1 Temperature detection limit ≥600K, temperature measurement range ≥300K.

[0022] This invention extends three-dimensional dynamic high-temperature real-time imaging technology to the aerospace industry. Based on the non-thermal coupled energy level fluorescence intensity ratio method for temperature measurement, it realizes three-dimensional dynamic high-temperature imaging and real-time temperature monitoring of the surface of engine turbine blades. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a single-layer structure design of an integrated temperature-sensitive thermal barrier protection A2B2O7 ceramic material disclosed in this invention; Figure 2 This is a schematic diagram of the light-emitting ion design principle of the present invention; Figure 3 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 XRD pattern of A2B2O7 ceramic material with integrated thermal barrier protection; Figure 4 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Excitation spectra of ceramic materials at 454 nm and 579 nm; Figure 5 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Emission spectrum of ceramic materials under 365nm excitation; Figure 6 In Embodiment 1 of the present invention (Y) 0.25 Gd0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The trend of the integrated intensity of the 454nm and 579nm emission peaks of ceramic materials as a function of temperature; Figure 7 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The integral intensity ratio (I) of the 454 nm emission peak and the 579 nm emission peak of the ceramic material 454 nm / I 579 Fitted curve of nm as a function of temperature; Figure 8 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 S of ceramic materials r Graph showing the change with temperature; Figure 9 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Thermal conductivity of ceramic materials as a function of temperature; Figure 10 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Curve of thermal expansion coefficient of ceramic materials as a function of temperature; Figure 11 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01Grain size changes of ceramic materials after being held at 1723K for different times; Figure 12 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Scanning electron microscope image of a cross section of a ceramic material after being etched by alkali metal CMAS at 1623K for 7 hours; Figure 13 In Embodiment 1 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Scanning electron microscope image of Vickers hardness indentation on the surface of ceramic material; Figure 14 La in Embodiment 2 of the present invention 1.95 Zr2O7:Tm 0.04 Dy 0.01 XRD pattern of A2B2O7 ceramic material with integrated thermal barrier protection; Figure 15 In embodiment 4 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Surface morphology image of the powder; Figure 16 In embodiment 4 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 A photograph of powder coating applied to turbine blades; Figure 17 In embodiment 4 of the present invention (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 A three-dimensional temperature measurement effect of powder on the surface of a turbine blade. Detailed Implementation

[0024] The following detailed description, with appropriate reference to the accompanying drawings, discloses an embodiment of the A2B2O7 ceramic material integrating temperature sensing and thermal barrier protection functions, its preparation method, and its application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0025] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0026] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0027] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0028] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0029] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0030] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0031] To achieve fluorescence temperature sensing, an A2B2O7 matrix is ​​doped with luminescent ions to produce emission that varies with temperature. Since turbine blades typically operate at very high temperatures, and thermal barrier coatings usually operate above these temperatures, stringent requirements are placed on the upper limit of temperature sensing. Luminescent materials often exhibit severe thermal quenching, which is detrimental to high-temperature measurement. Studies on suppressing luminescence thermal quenching have utilized the negative thermal expansion properties of materials or introduced defect energy levels as luminescence centers to compensate for energy loss and achieve reverse thermal quenching. However, these methods are not applicable to thermal barrier materials such as A2B2O7. Furthermore, the thermometry strategy based on thermally coupled energy level fluorescence intensity ratio is limited by the energy level spacing, which is detrimental to improving temperature sensitivity. Therefore, this invention selects to dope the A2B2O7 matrix with two or more luminescent ions that can produce significant emission, utilizing different combinations of luminescence centers to form a non-thermally coupled energy level fluorescence intensity ratio thermometry, thus overcoming the limitations of the energy level spacing. Meanwhile, by utilizing the cross-relaxation of the energy levels within the luminescent centers or the energy transfer process between luminescent centers, the thermal quenching effect of the luminescent centers is effectively improved, achieving reverse thermal quenching luminescence or low thermal quenching luminescence. Furthermore, based on the different temperature response characteristics among different luminescent ions, a synergistic improvement in both the upper limit of temperature measurement and the temperature measurement sensitivity is achieved. The design principle of the luminescent ion is as follows: Figure 2As shown. It must be noted that the co-doped luminescent ions include, but are not limited to, rare earth ions, transition metal ions, other main group metal ions, and combinations thereof. Multiple doped luminescent centers can all be excited by a common excitation source, and the emission peaks of different luminescent centers will not overlap.

[0032] In one embodiment of this application, an A2B2O7 ceramic material integrating temperature sensing and thermal barrier protection is proposed. This material achieves luminescence by doping a thermal barrier material A2B2O7 matrix with luminescent ions, and the luminescence exhibits temperature-dependent properties, thereby simultaneously realizing thermal barrier protection and luminescent temperature measurement. A schematic diagram of this structure in a turbine blade is shown below. Figure 1 As shown. This material has the general chemical formula A. 2-a B2O7:aX has a crystal structure that can be defect fluorite, pyrochlore, or a mixed two-phase structure. In the formula, element A includes at least one of La, Y, Lu, Gd, Sc, and Yb; element B includes at least one of Zr, Hf, Sn, and Ti; and X, as the doped luminescent ion, includes at least two elements, which can be rare earth ions, transition metal ions, other main group metal ions, or combinations thereof.

[0033] Secondly, the present invention provides a method for preparing an A2B2O7 ceramic material with integrated temperature sensing and thermal barrier protection functions, comprising the following steps: The first step involves weighing at least one type of element A oxide raw material (such as lanthanum oxide, yttrium oxide, scandium oxide, gadolinium oxide, lutetium oxide, ytterbium oxide, etc.), at least one type of element B oxide raw material with high purity (≥99.99%) (such as zirconium oxide, hafnium oxide, titanium oxide, tin oxide, etc.), and at least two types of luminescent oxide raw materials (such as dysprosium oxide, thulium oxide, europium oxide, manganese oxide, etc.) according to stoichiometric ratios. These raw materials are then transferred to a ball mill jar, and dispersant, sintering aid, dispersion medium, and ball milling pellets are added together. The ball mill jar is then placed in an all-around planetary ball mill and ball milled at a speed of 200-500 r / min for 28-45 h. The second step is to remove the slurry after ball milling and dry it in an oven at 80-150℃ for 12-20 hours. The dried powder is then placed in an agate mortar and ground for 30-45 minutes, followed by sieving through a 150-300 mesh sieve to obtain fine powder. The third step involves using a mold with a diameter of 10-20mm to dry press the powder into shape. After pressing, the powder is placed in a corundum boat and debinded in a muffle furnace. After being removed and sealed, it is then subjected to isotropic high pressure using a cold isostatic press to achieve uniform densification. The fourth step is to place the green body into a vacuum pulse Joule heating sintering furnace for high-temperature rapid sintering to obtain A2B2O7 ceramic material with integrated temperature sensing and thermal barrier protection functions.

[0034] The dispersant added in the first step is ammonium citrate (C6H4O). 17 N3O7 (N3O7) is used to promote uniform dispersion of powder and prevent agglomeration. Its proportion is 0.1-5% of the total mass of raw materials. If the content of dispersant is too low, it may not be able to fully adsorb on the powder surface to promote dispersion. If the content is too high, it may hinder the close contact of powder, affect the subsequent sintering process, and bring organic residues.

[0035] The sintering aid is tetraethyl orthosilicate (Si(OC2H5)4), which functions to form a liquid phase to promote sintering and lower the sintering temperature. Its proportion is 0.5-5% of the total mass of raw materials. If the content of the sintering aid is too low, the liquid phase may be insufficient and it will not be able to promote sintering. If the content is too high, the ceramic grain boundaries may be damaged and weakened, affecting the ceramic properties.

[0036] The added ball milling dispersion medium is ethanol or water, with a total mass ratio to raw materials of 0.7-1.2:1. If the proportion of dispersion medium is too low, the powder dispersibility is poor, easily agglomerating and sticking to the walls, resulting in decreased grinding efficiency. Simultaneously, insufficient heat dissipation can lead to localized overheating, potentially causing material oxidation or phase transformation and exacerbating equipment wear. If the content is too high, the medium will buffer the impact energy of the grinding balls, weakening the collision force, leading to reduced grinding efficiency, increased energy consumption, and possibly a wider particle size distribution of the product. Furthermore, excessively high media content will increase the cost of subsequent drying or processing. A 1:1 ratio is preferred.

[0037] The grinding balls used are either agate grinding balls or zirconia grinding balls, with a mix of different sizes, 4-8 mm and 1-3 mm in diameter, respectively. The ratio of the total mass of the grinding balls to the total mass of the raw material is 9-18:1. The preferred grinding ball sizes are 5 mm and 2 mm, with a ratio of 4:1.

[0038] The choice of material type for the grinding balls is crucial. This invention focuses on A2B2O7 material, which contains zirconium oxide. Therefore, to avoid introducing other impurities, zirconium oxide grinding balls were chosen. The mass ratio of grinding balls to raw materials (ball-to-material ratio) is a key parameter. If the ratio is too low, insufficient grinding energy input leads to low efficiency, uneven grinding, and easy product agglomeration. If the ratio is too high, a large amount of energy will be wasted on ineffective collisions between the grinding balls, resulting in poor economic efficiency, severe product contamination due to intense wear, and even over-pulverization of the material. The optimal ball-to-material ratio is 12:1.

[0039] Furthermore, in order to obtain a dense and crack-free green body, the dry pressing in the third step uses a pressure of 200-700 MPa, a holding time of 2-5 min, a glue discharge temperature of 500-800℃, a glue discharge time of 5-10 h, and a cold isostatic pressing pressure of 200-300 GPa, with a holding time of 100-200 s.

[0040] The purpose of debinding is to remove residual organic materials added during ball milling, thus preventing them from affecting the subsequent sintering process. If the debinding temperature is too low, the organic matter may not volatilize, resulting in residue. If the debinding temperature is too high, it may cause pre-sintering of the green body, leading to grain growth, etc.

[0041] When using a mold to dry press powder into shape, it is important to note that if the pressure is too low, the green body will not have a high density, resulting in a porous and loose ceramic after sintering. If the pressure is too high, the green body will crack.

[0042] The vacuum pulse Joule heating sintering furnace is a sintering device that can achieve rapid heating and cooling.

[0043] During the sintering process of ceramics, both sintering temperature and holding time have a significant impact on the luminescent properties and thermal barrier properties of ceramics.

[0044] Thirdly, this invention provides an A2B2O7 ceramic material with integrated temperature sensing and thermal barrier protection functions for temperature measurement in aero-engine turbine blades and related hot-end components, realizing three-dimensional real-time temperature measurement of turbine blades.

[0045] This invention involves spraying fluorescent powder of the same composition onto turbine blades to form a coating, thereby enabling temperature measurement.

[0046] Example The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0047] Example 1 A method for preparing an A2B2O7 ceramic material with integrated temperature sensing and thermal barrier protection functions includes: The first step is to follow (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Tm 0.04 Dy 0.01 The chemical structure of Zr2O7 is determined by stoichiometry. 10g of high-purity (≥99.99%) Y2O3, Gd2O3, Lu2O3, Sc2O3, Tm2O3, Dy2O3, and ZrO2 raw materials were weighed and transferred to a 250mL nylon ball mill jar. Simultaneously, 1%wt and 0.5%wt of C6H were added, respectively. 17N3O7 and Si(OC2H5)4 were used as dispersants and sintering aids. Zirconia ball milling mills with diameters of 5 mm and 2 mm were then added, with a mass ratio of large to small milling mills of 4:1. Anhydrous ethanol was added as the milling medium, with a mass consistent with that of the powder mixture. The milling jar was then placed in an omnidirectional planetary ball mill and milled at 400 rpm for 33 hours to obtain a slurry. The second step involves filtering the mixture in the milling jar using a filter screen after ball milling to obtain a slurry. This slurry is then dried in a 100°C forced-air drying oven for 10 hours. The dried powder is then removed, ground in an agate mortar for 30 minutes, and sieved through a 250-mesh screen to obtain a fine powder. The third step involves weighing an appropriate amount of fine powder (0.17~0.23g) and placing it into a 10mm diameter tableting mold. The powder is then held under 400MPa pressure for 3 minutes, and demolded to obtain a green compact. The green compact is then placed in a corundum boat and placed in a muffle furnace at 800℃ for 8 hours to remove the binder. To further densify the green compact, it is sealed in a plastic bag and then placed in a cold isostatic press under 250MPa pressure for 3 minutes.

[0048] The fourth step involves cutting two 2*5cm sheets of carbon cloth and placing the green blank between them. After clamping with copper sheets, it is fixed in a vacuum pulse Joule heating furnace and then rapidly sintered at 1700℃ for 30 seconds under a vacuum of 1.7 Pa to obtain (Y). 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 A2B2O7 ceramic material integrating temperature sensing and thermal barrier protection functions, its XRD pattern is as follows: Figure 3 As shown.

[0049] Figure 4 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The excitation spectra of the ceramic material at 454 nm and 579 nm. The two different emission peaks in the spectrum show a common excitation band in the 355-370 nm range. The 365 nm light source is the most readily available, which is convenient for subsequent testing and application. Therefore, this invention selects 365 nm as the excitation wavelength.

[0050] Figure 5 In this example (Y) 0.25 Gd0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The emission spectrum of the ceramic material under 365nm excitation shows that the ceramic exhibits multiple emission peaks, with the strongest at 454nm and 579nm, which are attributed to Tm. 3+ and Dy 3+ The energy level transition launch.

[0051] Figure 6 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The graph shows the trend of the integrated intensity of the 454nm and 579nm emission peaks of the ceramic material as a function of temperature. It can be seen that as the temperature increases, the intensity of the 454nm emission peak first increases and then decreases, while the intensity of the 579nm emission peak gradually weakens. Both emission peaks still have a certain luminescence intensity at 1300K, which indicates that the material can achieve an ultra-high temperature detection limit.

[0052] Figure 7 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The integral intensity ratio (I) of the 454 nm emission peak and the 579 nm emission peak of the ceramic material 454 nm / I 579 The fitted curve of the integral intensity ratio (nm) versus temperature shows that the integral intensity ratio exhibits a good parabolic relationship with temperature in the two temperature ranges (300K-800K; 800K-1300K), and can be used as a temperature sensing parameter.

[0053] Figure 8 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The graph shows the Sr content of ceramic materials as a function of temperature. It can be seen that S... r It reaches its maximum value of 0.74%K in the high-temperature region. -1 .

[0054] Figure 9 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The thermal conductivity of the ceramic material varies with temperature. It can be seen that in the temperature range of 298-800 K, the thermal conductivity decreases with increasing temperature; however, when the temperature exceeds 800 K, the thermal conductivity increases with increasing temperature. The lowest thermal conductivity, only 1.77 W·m, is observed at 773 K. -1 ·K -1 When the temperature exceeds 800 K, the thermal conductivity of the sample increases relatively slowly, reaching 1.97 W·m at 1273 K. -1 ·K -1 .

[0055] Figure 10 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The curve showing the change in the coefficient of thermal expansion of ceramic materials with temperature. It can be seen that the coefficient of thermal expansion of ceramic materials gradually increases with temperature, reaching a maximum value of 11.38 × 10⁻⁶ K at 1473 K. -6 K -1 .

[0056] Figure 11 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The grain size variation of the ceramic material after holding at 1723 K for different times is shown. It can be seen that a small grain size contributes to achieving low thermal conductivity and excellent mechanical properties. Meanwhile, as the holding time increases from 1 h to 16 h, the median grain size (D...)... 50 The grain size only increased from 1.49 μm to 1.77 μm, with a grain growth rate of only 19%, exhibiting excellent anti-sintering properties.

[0057] Figure 12 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm0.04 Dy 0.01 Scanning electron microscope (SEM) image of the cross-section of the ceramic material after corrosion by alkali metal CMAS at 1623 K for 7 hours. It can be seen that the corroded area is shallow, only about 36 μm, indicating good resistance to CMAS corrosion.

[0058] Figure 13 In this example (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 Scanning electron microscope images of Vickers hardness indentations on the surface of ceramic materials. It can be seen that the average diagonal of the indentation is short, indicating short cracks. Calculations show that the average hardness is 13.75 Pa and the average fracture toughness is 1.13 MPa·m. 1 / 2 It has good mechanical properties.

[0059] Example 2 The preparation method is the same as in Example 1, except that the chemical structural formula of this material is La. 1.95 Tm 0.04 Dy 0.01 Zr2O7 is made from La2O3, Tm2O3, Dy2O3 and ZrO2.

[0060] Figure 14 La in Embodiment 2 of the present invention 1.95 Zr2O7:Tm 0.04 Dy 0.01 XRD pattern of A2B2O7 ceramic material integrating temperature sensing and thermal barrier protection. Its upper temperature limit is 1300K, and its highest relative sensitivity is 0.65%K. -1 The material has a thermal conductivity of 2.39 W·m at 1273 K. -1 ·K -1 Its coefficient of thermal expansion at 1473 K is 9.58 × 10⁻⁶. -6 K -1 .

[0061] Example 3 The preparation method is the same as in Example 1, except that the chemical structural formula of this material is Gd. 1.95 Zr2O7:Tm 0.04 Dy 0.01 The raw materials are Gd2O3, Tm2O3, Dy2O3 and ZrO2.

[0062] Example 4 (Y 0.25 Gd 0.25 Lu0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The preparation method of the powder before sintering is the same as in Example 1, except that the powder sintering does not require pressing or subsequent steps. The sieved fine powder is placed in a muffle furnace and sintered at 1575℃ for 5 hours. The sintered powder is then ground in an agate mortar for 30 minutes and sieved through a 250-mesh sieve to obtain phosphor. This phosphor is then sprayed onto the turbine blade to form a coating approximately 50 μm thick. The application device consists of two high-speed cameras equipped with narrowband filters of 454 nm and 579 nm (20 nm bandwidth), located on the left and right sides of the blade, each operating at a frame rate of 20 fps. A 365 nm LED excitation light source is located in the middle of the blade; a 600K heat source is used to locally heat the blade to create a non-uniform temperature field, increasing the thermocouple contact with the blade surface for comparative temperature measurement. The cameras and LEDs are controlled by a signal generator. Finally, the imaging and temperature data are output through signal conversion to achieve temperature sensing of the turbine blade.

[0063] Figure 15 In Example 4 (Y) 0.25 Gd 0.25 Lu 0.25 Sc 0.25 ) 1.95 Zr2O7:Tm 0.04 Dy 0.01 The surface morphology image of the powder shows that the particle size is 1.09 μm.

[0064] Figure 16 This is a photograph of the powder coating applied to the turbine blades in Example 4.

[0065] Figure 17 This is a diagram illustrating the actual effect of 3D temperature measurement.

[0066] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A thermosensitive thermal barrier integrated A2B2O7 ceramic material, characterized in that, The material is obtained by doping rare earth ions into the thermal barrier material A2B2O7, and its crystal structure can be defective fluorite type, pyrochlore type or mixed dual phase, thus possessing luminescent temperature sensing function and thermal barrier protection function.

2. The integrated A2B2O7 ceramic material for temperature-sensing thermal barrier protection according to claim 1, characterized in that, The chemical formula of the material is A. 2-a B2O7:aX, wherein element A includes at least one of La, Y, Lu, Gd, Sc, and Yb, element B includes at least one of Zr, Hf, Sn, and Ti, and X is at least two doped luminescent ions, which can be rare earth ions, transition metal ions, other main group metal ions, or combinations thereof.

3. The integrated A2B2O7 ceramic material for temperature-sensing thermal barrier protection according to claim 2, characterized in that, The doped luminescent ions emit light after entering the crystal lattice. The excitation spectra of different doped luminescent ions overlap, allowing them to be excited by a common excitation wavelength. Furthermore, the luminescence exhibits temperature-dependent characteristics. The selected A₂B₂O₇ material has a thermal conductivity ≤2.8 W·m. -1 ·K -1 Coefficient of thermal expansion ≥ 8.5 10 -6 K -1 Fracture toughness ≥ 0.75 MPa·m 1 / 2 Vickers hardness ≥ 8.5 GPa.

4. The integrated A2B2O7 ceramic material for temperature-sensing thermal barrier protection according to claim 2 or 3, characterized in that, The main emission peaks of the two or more doped luminescent ions do not overlap, and the energy level difference between the luminescent ions is ≥2000 cm⁻¹. -1 This method can be used for thermometry based on the fluorescence intensity ratio of non-thermally coupled energy levels, overcoming the limitations of relative sensitivity in traditional thermally coupled energy level thermometry. The luminescent ions possess different thermal quenching characteristics, which can extend the upper limit of temperature measurement (≥800K) and the relative sensitivity (≥0.3%K). -1 ).

5. A method for preparing an integrated temperature-sensitive thermal barrier protection A2B2O7 ceramic material, characterized in that, Includes the following steps: S1. Weigh at least one high-purity (≥99.99%) element A oxide raw material, at least one high-purity (≥99.99%) element B oxide raw material, and at least two luminescent ion oxide raw materials according to the stoichiometric ratio. At the same time, add dispersant, sintering aid, ball milling dispersion medium, and ball milling pellets in a certain proportion. Transfer all raw materials to a ball milling jar and ball mill them at a rotation speed of 200-500 r / min for 28-45 h using an all-round planetary ball mill. S2, After ball milling, remove the slurry and dry it in an oven at 80-150℃ for 12-20 hours; then place the dried powder in an agate mortar and grind it for 30-45 minutes, and then sieve it through a 150-300 mesh sieve to obtain fine powder. S3 uses a tableting mold of a certain diameter to dry press the powder into shape. After pressing, it is placed in a corundum boat and debinded in a muffle furnace. After being taken out and sealed, it is subjected to isotropic high pressure by a cold isostatic press to achieve uniform densification. S4. The green body is placed in a vacuum pulse Joule heating sintering furnace for high-temperature rapid sintering to obtain an integrated A2B2O7 ceramic material with temperature-sensitive thermal barrier protection.

6. The preparation method of the integrated temperature-sensing thermal barrier protection A2B2O7 ceramic material according to claim 5, characterized in that, The oxide of element A is lanthanum oxide, yttrium oxide, scandium oxide, gadolinium oxide, ytterbium oxide, or lutetium oxide; the oxide of element B is zirconium oxide, hafnium oxide, titanium oxide, or tin oxide; and the luminescent ion oxide is a rare earth ion, a transition metal ion, or an oxide of another main group metal ion.

7. The preparation method of the integrated temperature-sensing thermal barrier protection A2B2O7 ceramic material according to claim 5, characterized in that, The dispersant is ammonium citrate (C6H4O). 17 The addition ratio of N3O7 is 0.1-5% of the total mass of the raw materials; the sintering aid is tetraethyl orthosilicate (Si(OC2H5)4), and the addition ratio is 0.5-5% of the total mass of the raw materials; the ball milling dispersion medium is ethanol or water, and its mass ratio with the total mass of the raw materials is 0.7-1.2:1; the ball milling particles are agate ball milling particles or zirconia ball milling particles, and the total mass ratio of the ball milling particles to the total mass of the raw materials is 9-18:1; the ball milling particles are mixed with different sizes, with diameters of 4-8 mm and 1-3 mm respectively.

8. The preparation method of the integrated temperature-sensing thermal barrier protection A2B2O7 ceramic material according to claim 5, characterized in that, The dry pressing pressure is 200-700MPa, and the holding time is 2-5min; the glue discharge temperature is 500-800℃, and the glue discharge time is 5-10h; the cold isostatic press pressure is 200-300GPa, and the holding time is 100-200s.

9. The preparation method of an integrated temperature-sensitive thermal barrier protection A2B2O7 ceramic material according to claim 6, characterized in that, The vacuum pulse Joule heating sintering furnace heats the temperature from room temperature to 1550-1850°C in 2-5 seconds, and the sintering time is 20-45 seconds.

10. An application of an integrated temperature-sensing thermal barrier protection A2B2O7 ceramic material, including the ceramic material described in any one of claims 1-4 or the ceramic material obtained by the preparation method described in any one of claims 5-9, for temperature measurement in aero-engine turbine blades and related hot-end components, realizing three-dimensional real-time temperature measurement of turbine blades.

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