High-temperature sensitive film, preparation method and sensor preparation process based on high-temperature sensitive film

Abstract

The invention belongs to the technical field of high-temperature film sensors, and discloses a high-temperature sensitive film, a preparation method and a sensor preparation process based on the high-temperature sensitive film. The preparation method comprises the following steps: preparing an initial-state ABO film on the surface of a substrate by adopting a film preparation technology; and carrying out heat treatment on the initial-state ABO thin film at high temperature to obtain a final-state thin film with single-phase composition, preferred crystal orientation, refined grains, compactness and no pore. The high-temperature ABO ceramic sensing film integrates the temperature sensing function, the strain sensing function, the heat flow sensing function and the pressure sensing function, the temperature measurement upper limit of the high-temperature ABO ceramic sensing film can reach 1600 DEG C, no packaging protection layer is needed, the process steps are simplified, the preparation cost of the multifunctional film sensor is reduced, the high-temperature film sensor can be further integrated and miniaturized according to the design requirements, and the high-temperature ABO ceramic sensing film has good application prospects. The product can meet long-term real-time on-line measurement of temperature, strain, heat flow and pressure signals of a high-temperature end above 1400 DEG C.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature thin-film sensors, and relates to a high-temperature sensitive thin film with multiple sensing functions of temperature, strain, pressure, and heat flux, and a preparation process of a high-temperature multifunctional sensor based on the sensitive thin film. Background Art

[0002] In the aerospace field, high-temperature thin-film sensors with sensing functions such as temperature, strain, heat flux, and pressure can realize in-situ real-time monitoring of various signals of high-temperature hot-end components and evaluation of service states in extreme environments. This helps to feedback the design and manufacturing of key components of aircraft and prevent potential major accidents. However, the sensitive materials used in traditional high-temperature thin-film sensors face a series of problems, including limited temperature range, low sensitivity coefficient, and the need for complex and expensive process flows to integrate single-function thin films for multifunctional measurement due to different self-properties and preparation processes. Chinese invention patent CN114910185A prepares a high-temperature thin-film temperature sensor based on indium tin oxide sensitive thin film by laser pyrolysis direct writing method, which can only work stably at 800°C. Chinese invention patent CN116734720A prepares a high-temperature thin-film strain gauge with PdCr as the sensitive thin film combined with optimized insulation layer and protective layer preparation processes, which can also only work within the range of 900°C. In addition, a strain-temperature dual-parameter high-temperature thin-film sensor disclosed in Chinese invention patent CN116399398A uses a PtW-PtRh thin-film combination to achieve dual detection of strain and temperature. Specifically, the PtW thin film forms a serpentine structure thin-film strain gauge, and the PtW thin film and the PtRh thin film partially overlap to form a thin-film thermocouple. It not only has a complex structure and uses sputtering coating process multiple times, but also uses noble metal thin films, resulting in high costs.

[0003] With the development of new-generation aerospace technologies, the temperature in the key hot-end component areas of aerospace can reach as high as 1500°C to 2000°C, and the requirements for the performance and integrated measurement of high-temperature thin-film sensors in high-temperature extreme environments are further improved. In the design of multifunctional high-temperature thin-film sensors, how to achieve multiple signal monitoring based on only one sensing material while having excellent high-temperature resistance and sensitivity is a key difficulty. However, the current commonly used high-temperature sensing functional thin films have a maximum temperature resistance of 1200°C and do not have multifunctional sensing performance, making it difficult to meet the real-time signal detection at higher temperatures. Summary of the Invention

[0004] The purpose of the present invention is to address the above problems by providing a new type of multifunctional high-temperature sensing thin-film material and preparing a multifunctional high-temperature thin-film sensor based on this single sensing material, so as to solve the problems of low upper limit of working temperature, small sensitivity, poor linearity, and difficulty in multifunctional sensing integration and integration of existing high-temperature thin-film sensors.

[0005] Technical solution of the present invention:

[0006] A high-temperature sensitive film, which is a novel multifunctional high-temperature ceramic sensitive film ABO; wherein, A represents one of the trivalent elements Sc and Y in Group III, B represents one of the tetravalent elements Ti, Zr, and Hf in Group IV, and O represents oxygen element; in the novel multifunctional high-temperature ceramic sensitive film ABO, the oxide A x O 1.5x and the oxide B y O 2y The total composition of is 100%, wherein the content of the oxide A x O 1.5x is between 1% and 10%, and the content of the oxide B y O 2y is between 90% and 99%; in addition, the multifunctional high-temperature ceramic sensing film contains but is not limited to only the three elements ABO, and on the basis of the three elements ABO, other element C is doped to form an ABCO film; wherein, C is one or more of the elements La, Ce, Sm, Gd, Sr, Ca, Mg, Al, and Ga.

[0007] A preparation method of a high-temperature sensitive film, comprising the following steps:

[0008] Using a film-making technique to prepare the film on the surface of the substrate to obtain an initial-state film;

[0009] Heat-treating the initial-state film at a high temperature to obtain a final-state film with a single-phase composition, preferred crystal orientation, refined grains and uniform size, and dense and pore-free;

[0010] The film-making technique includes one of the methods of sol-gel, spray pyrolysis, electrospinning, chemical vapor deposition, atomic layer deposition, electron beam evaporation, pulsed laser deposition, and magnetron sputtering;

[0011] The substrate is one of oxide ceramics, nitride ceramics, boride ceramics, and carbide ceramics;

[0012] The temperature of the heat treatment is 1000°C to 2000°C;

[0013] The heating rate of the heat treatment is 1°C to 20°C / min;

[0014] The time of the heat treatment is 1 h to 10 h;

[0015] The single phase formed after the heat treatment of the high-temperature sensitive film includes one of monoclinic phase, tetragonal phase, cubic phase, and orthorhombic phase;

[0016] The preferred crystal orientations formed after heat treatment of the high-temperature sensitive film include one of the directions of (001), (110), (101), (111), (-111), (200), and (220);

[0017] The thickness of the high-temperature sensitive film is 1 nm to 1 mm.

[0018] A preparation process for a sensor based on a high-temperature sensitive film includes the following steps:

[0019] Connect leads to the high-temperature sensitive film to obtain a sensor based on the high-temperature sensitive film.

[0020] The shape of the high-temperature sensitive film in the sensor based on the high-temperature sensitive film is one or a combination of two or more of a grid wire shape, an S shape, and a straight line shape;

[0021] The lead is a high-temperature wire with a diameter of 0.1 mm to 0.3 mm. High-temperature conductive paste is coated at the connection, and the paste is preliminarily cured at 50°C to 200°C.

[0022] The beneficial effects of the present invention:

[0023] A high-temperature sensitive film and a preparation method for a sensor based on the film according to the present invention propose an ABO ceramic sensing film material that simultaneously has multiple sensing functions of temperature, strain, pressure, and heat flux. In addition to being an oxide material that can resist high-temperature oxidation itself, the ABO sensitive film prepared by the film-making technology can also suppress the generation of cracks due to the expansion stress generated during the transformation from the initial multi-phase composition to the final single-phase structure during the heat treatment process, thereby achieving the purpose of toughening. In addition, the dense, uniform, grain-refined, and pore-free defect structure formed after high-temperature heat treatment further enables the film to maintain stable performance at high temperatures. Most importantly, while obtaining a stable structure at high temperatures, the film also simultaneously has temperature, strain, heat flux, and pressure sensing functions, which provides a basis for designing a multifunctional film sensor based on a single sensing material and applied at high temperatures.

[0024] The high-temperature multifunctional thin-film sensor based on the ABO sensing thin film integrates temperature, strain, heat flux, and pressure sensing functions, solving the problem of realizing multiple sensing functions based on a single sensitive material under high-temperature conditions. Its upper temperature measurement limit can reach 1600 °C without any encapsulation protective layer. Compared with existing high-temperature thin-film sensors with an average operating temperature of 1000 °C, it has increased by 600 °C; compared with the preparation process of existing high-temperature thin-film sensors, the process of preparing the protective layer is reduced, and the technological steps are simplified; compared with the preparation process of existing integrated high-temperature thin-film sensors, which require a mixture of multiple sensitive materials, the process is complex, the cost is high, and the performance parameters between multiple sensitive materials do not match easily, making it difficult to achieve further miniaturization and integration. The present invention uses only a single sensing material to achieve multiple signal detections, without the problem of mismatched performance of sensitive materials, and the process is simple, the cost is low, and it can be further integrated and miniaturized according to design requirements. Description of the Drawings

[0025] Figure 1(a) is a scanning electron microscope image of the prepared initial-state ABO thin film in an embodiment of the present invention;

[0026] Figure 1(b) is a scanning electron microscope image of the final state of the prepared ABO thin film after high-temperature heat treatment in an embodiment of the present invention;

[0027] Figure 1(c) is an X-ray diffraction pattern of the prepared initial-state and final-state ABO thin films after high-temperature heat treatment in an embodiment of the present invention;

[0028] Figure 2(a) is a schematic structural diagram of a high-temperature multifunctional thin-film sensor based on the ABO sensing thin film in an embodiment of the present invention;

[0029] Figure 2(b) is a resistance-temperature test curve of a high-temperature multifunctional thin-film sensor based on the ABO sensing thin film from 700 °C to 1600 °C in an embodiment of the present invention;

[0030] Figure 2(c) is a resistance-strain test curve of a high-temperature multifunctional thin-film sensor based on the ABO sensing thin film at 1475 °C in an embodiment of the present invention;

[0031] Figure 2(d) is a resistance drift curve of a high-temperature multifunctional thin-film sensor based on the ABO sensing thin film at 1500 °C in an embodiment of the present invention;

[0032] In the figure: 1 - alumina ceramic substrate, 2 - ABO sensitive thin film, 3 - lead wire. Detailed Embodiments

[0033] The following details the specific embodiments of the present invention in conjunction with the technical solutions and drawings.

[0034] Embodiment

[0035] A high-temperature ceramic sensitive thin film material with temperature, strain, pressure, and heat transfer sensing functions simultaneously, and a preparation method of a high-temperature multifunctional thin film sensor based on this thin film.

[0036] The high-temperature ceramic sensitive thin film includes two metal elements A and B and oxygen element O, simply referred to as ABO. Among them, A represents one of the trivalent elements Sc and Y in Group III, and B represents one of the tetravalent elements Ti, Zr, and Hf in Group IV; in the ABO thin film, oxide A x O 1.5x and oxide B y O 2y The total composition of is 100%, and the content of oxide A x O 1.5x is one of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and the content of oxide B y O 2y is one of 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%. In addition, this multifunctional high-temperature ceramic sensing thin film contains but is not limited to three elements of ABO. On the basis of the three elements of ABO, other elements C can also be doped to form an ABCO thin film. Among them, C is a representative of one or more elements, specifically including one or more of the elements La, Ce, Sm, Gd, Sr, Ca, Mg, and Al. The preparation process of this thin film includes the following steps:

[0037] Step 1: Soak the alumina ceramic substrate in acetone, ethanol, and deionized water in sequence, while performing ultrasonic treatment, and then heat and dry it on a hot plate;

[0038] Step 2: Use a film-making technology to sputter an initial-state ABO thin film in the shape of a grid wire on the alumina ceramic substrate using a mask plate. The preparation conditions are: prepared by radio frequency magnetron sputtering method, the constant power set for magnetron sputtering is one of 50W, 100W, 150W, 200W, 250W, 300W, the sputtering gas pressure is one of 0.3Pa, 0.5Pa, 0.7Pa, 0.9Pa, the vacuum environment is 3.0×10 -3 Pa, the sample stage rotation speed is one of 5rpm, 7rpm, 10rpm, and the target-substrate distance is one of 7cm, 9cm, 10cm, 11cm, 12cm, 13cm;

[0039] Step 3: Heat-treat the prepared initial-state ABO thin film at high temperature to form the final-state ABO sensitive thin film. The specific heat-treatment process is as follows: the heating rate of the heat treatment is one of 1 °C / min, 5 °C / min, 10 °C / min, 15 °C / min, and 20 °C / min; the heat-treatment temperature is one of 1000 °C, 1200 °C, 1400 °C, 1600 °C, 1800 °C, and 2000 °C; the heat-treatment time is one of 1 h, 3 h, 5 h, 7 h, and 10 h; the single phase formed after the heat treatment of the final-state ABO sensitive thin film includes one of monoclinic phase, tetragonal phase, cubic phase, and orthorhombic phase; the preferred crystal orientation formed after the heat treatment of the final-state ABO sensitive thin film includes one of the directions of (001), (110), (101), (111), (-111), (200), and (220); the thickness of the ABO sensitive thin film is one of 100 nm, 300 nm, 500 nm, 700 nm, 1 μm, 3 μm, 5 μm, 7 μm, 10 μm, 100 μm, 300 μm, 500 μm, and 1 mm. The initial-state ABO sensitive thin film has a multi-phase composition. After high-temperature annealing, it will form a single-phase structure, as well as a preferred crystal orientation and uniform grain size. The single-phase structure and the preferred crystal orientation will, on the one hand, reduce the porosity in the thin film, thereby improving the overall density of the thin film, and toughen the thin film during the phase transition process, thereby enhancing the thermal stability of the sensitive thin film at high temperature; on the other hand, under the single-phase composition and the preferred crystal orientation structure, the thin film has the optimal high-temperature carrier mobility and signal detection sensitivity, and the uniform grain size further enhances the conductivity of the thin film.

[0040] The preparation process of the high-temperature multifunctional thin-film sensor includes the following steps:

[0041] Step 4: Connect leads to the final-state ABO sensitive thin film prepared by using the above preparation method; the leads are high-temperature wires with a diameter of 0.1 mm, and high-temperature conductive paste is used to coat the connection, and the paste is preliminarily cured at 200 °C.

[0042] Figures 1(a), (b), and (c) are respectively the scanning electron microscope images and X-ray diffraction patterns of the initial-state ABO thin film and the final-state ABO thin film after high-temperature heat treatment prepared in the embodiments of the present invention. It can be clearly seen from the comparison between Figure 1(a) and Figure 1(b) that the pore defects of the final-state ABO thin film after high-temperature heat treatment are significantly reduced, the thin film becomes dense, and the grain size is significantly reduced and evenly distributed, which reduces the obstacles for carriers to transfer in the thin film and enhances the conductivity of the thin film. It can be seen from Figure 1(c) that the final-state ABO thin film after high-temperature heat treatment has an obvious single-phase structure and a preferred crystal orientation, and this structure enables the thin film to have the optimal high-temperature carrier mobility and signal detection sensitivity at high temperature.

[0043] Figure 2(a) is a schematic structural diagram of the high-temperature multifunctional thin-film sensor prepared based on the ABO-sensitive thin film in the embodiment of the present invention.

[0044] Figure 2(b), (c), and (d) are respectively the resistance-temperature test curve of the high-temperature multifunctional thin-film sensor of the present invention from 700 °C to 1600 °C, the resistance-strain test curve at 1475 °C, and the resistance drift curve at 1500 °C.

[0045] It can be seen from Figure 2(b) that the resistance-temperature curve of the high-temperature multifunctional thin-film sensor from 700 °C to 1600 °C shows a linear relationship after logarithmic processing, which demonstrates its excellent temperature and heat flux detection performance; it can be seen from Figure 2(c) that at a temperature as high as 1475 °C, the high-temperature multifunctional thin-film sensor still has an excellent resistance-strain response relationship and excellent sensitivity, which demonstrates its excellent strain and pressure detection performance; it can be seen from Figure 2(d) that the high-temperature multifunctional thin-film sensor has excellent stability in a high-temperature environment of 1500 °C.

[0046] The high-temperature ceramic sensitive thin-film material of the present invention that simultaneously has temperature, strain, pressure, and heat flux sensing functions and the high-temperature multifunctional thin-film sensor prepared based on this thin film can reach a temperature resistance upper limit of 1600 °C. Compared with the general working temperature upper limit of 1000 °C of the current high-temperature thin-film sensors, it has increased by 600 °C. At the same time, it realizes multiple-function sensing of the thin-film sensor based on a single sensing material in a high-temperature environment, and also has excellent high-temperature stability and sensitivity. The multifunctional high-temperature thin-film sensor prepared by the present invention can meet the real-time in-situ online measurement of temperature, strain, pressure, and heat flux signals at high-temperature ends above 1400 °C, providing a new technical method for reliable and accurate measurement of high-temperature hot-end components in the field of aerospace technology.

Claims

1. A high-temperature sensitive film, characterized in that, The high-temperature sensitive thin film is a novel multifunctional high-temperature ceramic sensitive thin film ABO; wherein, A represents one of the trivalent elements Sc and Y in Group III, B represents one of the tetravalent elements Ti, Zr, and Hf in Group IV, and O represents oxygen element.

2. The high-temperature sensitive film according to claim 1, wherein In the new multifunctional high-temperature ceramic sensitive film ABO, oxide A x O 1.5x and oxide B y O 2y have a total composition of 100%, where the content of oxide A x O 1.5x is between 1% and 10%, and the content of oxide B y O 2y is between 90% and 99%.

3. The high-temperature sensitive film according to claim 1, characterized in that The high-temperature sensitive thin film is further doped with other element C to form an ABCO thin film; wherein, C is one or more of the elements La, Ce, Sm, Gd, Sr, Ca, Mg, Al, and Ga.

4. A method for preparing the high-temperature sensitive thin film according to any one of claims 1-3, characterized in that, It includes the following steps: The thin film is prepared on the substrate surface by a film preparation technique to obtain an initial-state thin film. The initial-state thin film is heat-treated at a high temperature to obtain a final-state high-temperature sensitive thin film with a single-phase composition, preferred crystal orientation, refined grains with uniform size, and being dense and pore-free.

5. The preparation method according to claim 4, characterized in that, The film preparation technique includes one of sol-gel, spray pyrolysis, electrospinning, chemical vapor deposition, atomic layer deposition, electron beam evaporation, pulsed laser deposition, and magnetron sputtering methods.

6. The preparation method according to claim 4, characterized in that, The substrate is one of oxide ceramics, nitride ceramics, boride ceramics, and carbide ceramics.

7. According to the preparation method described in claim 4, characterized in that The temperature of the heat treatment is 1000°C to 2000°C; The heating rate of the heat treatment is 1°C to 20°C / min; The time of the heat treatment is 1 h to 10 h.

8. According to the preparation method described in claim 4, characterized in that The single phase formed after the heat treatment of the high-temperature sensitive thin film includes one of monoclinic phase, tetragonal phase, cubic phase, and orthorhombic phase; The preferred crystal orientation formed after the heat treatment of the high-temperature sensitive thin film includes one of the directions (001), (110), (101), (111), (-111), (200), and (220); The thickness of the high-temperature sensitive thin film is 1 nm to 1 mm.

9. A preparation process of a sensor based on the high-temperature sensitive film described in claims 1-3, characterized in that, It includes the following steps: Leads are connected to the high-temperature sensitive thin film to obtain a sensor based on the high-temperature sensitive thin film.

10. According to the sensor preparation method described in claim 9, characterized in that The shape of the high-temperature sensitive thin film in the sensor based on the high-temperature sensitive thin film is one or a combination of two or more of grid wire shape, S shape, and straight shape; The leads are high-temperature wires with a diameter of 0.1 mm to 0.3 mm. High-temperature conductive paste is coated at the connection, and the paste is preliminarily cured at 50°C to 200°C.

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