A thin film temperature sensor, a method of manufacturing the same, and a temperature field measurement method

Abstract

The application relates to a thin film temperature sensor and a preparation method and a temperature field measurement method thereof, and belongs to the technical field of temperature sensors. The thin film temperature sensor has semiconductor characteristics. The thin film temperature sensor comprises SiBCN ceramics and fillers. The thin film temperature sensor provided by the application has high compactness, good surface quality, strong bonding capacity with a substrate, and is not easy to fall off. The thin film temperature sensor has obvious semiconductor characteristics in the range of 0-800 DEG C, and can meet the temperature field measurement requirements of workpiece surfaces of different materials, planes, curved surfaces and special-shaped structures under high-temperature working conditions.

Description

Technical Field

[0001] This invention relates to the field of temperature sensor technology, and in particular to a thin-film temperature sensor, its fabrication method, and a temperature field measurement method. Background Technology

[0002] Equipment such as aero-engines, large gas turbines, hypersonic vehicles, and rocket propulsion systems often operate in "extreme environments" characterized by high temperatures, high corrosion, high airflow impact, and high loads. Abnormally elevated temperatures on the surfaces of high-temperature hot-end components can easily cause irreversible damage to these equipment. Therefore, monitoring the temperature field distribution on the surfaces of these components is of great significance.

[0003] However, traditional temperature sensors often require drilling holes in the workpiece surface, which not only causes irreversible intrusion damage to its structure, but also makes it difficult to fully fit the workpiece surface, resulting in low temperature measurement accuracy. More importantly, traditional temperature sensors can only achieve one-dimensional point temperature measurement and cannot achieve temperature field distribution measurement at two or more levels.

[0004] Therefore, there is an urgent need to provide a temperature sensor that can measure the surface temperature field of a high-temperature hot end. Summary of the Invention

[0005] To address one or more technical problems existing in the prior art, the present invention provides a thin-film temperature sensor, its preparation method, and a temperature field measurement method. The thin-film temperature sensor provided by the present invention has high density, good surface quality, strong adhesion to the substrate, and is not easy to fall off. It exhibits obvious semiconductor characteristics in the range of 0 to 800°C, and can meet the temperature field measurement needs of planar, curved, and irregularly shaped workpiece surfaces of different materials under high-temperature conditions.

[0006] The present invention provides a thin-film temperature sensor in a first aspect, the thin-film temperature sensor having semiconductor properties; the thin-film temperature sensor includes SiBCN ceramic and filler.

[0007] The present invention provides a method for fabricating the thin-film temperature sensor described in the first aspect in a second aspect, the method comprising:

[0008] S1. Mix polyborosilazane, filler and organic solvent to obtain film slurry;

[0009] S2. The thin film slurry is sprayed onto a preheated substrate, cured, and pyrolyzed to obtain a thin film temperature sensor.

[0010] Preferably, based on the total mass of the polyborosilazane and the filler, the polyborosilazane accounts for 50-70 wt%, and the active filler accounts for 30-50 wt%.

[0011] Preferably, the organic solvent accounts for 40-60% of the total mass of the polyborosilazane and the filler.

[0012] Preferably, the filler is selected from at least one of active fillers and inert fillers; the active filler is preferably at least one of Al, B, Cr, W, Nb, Mo, Si, Ti, V, CrSi2, MoSi2, TiSi2, and TiB2; the inert filler is preferably at least one of SiO2, Al2O3, Zr2O3, Y2O3, SiC, B4C, Si3N4, and BN; and / or

[0013] The organic solvent is xylene.

[0014] Preferably, the temperature of the preheating treatment is 80–100°C.

[0015] Preferably, the curing is carried out under a flowing argon atmosphere at a curing temperature of 300–400°C; and / or

[0016] The pyrolysis was carried out in a flowing argon atmosphere at a temperature of 1000–1200°C.

[0017] The present invention provides a temperature field measurement method in a third aspect, implemented using the thin-film temperature sensor described in the first aspect, comprising the following steps:

[0018] A thin-film temperature sensor is fabricated on the surface of the workpiece to be tested, and multiple electrodes are connected at the boundary position of the thin-film temperature sensor to obtain the voltage distribution at the boundary of the thin-film temperature sensor under a preset current.

[0019] Based on the voltage distribution at the boundary of the thin-film temperature sensor under a preset current, the resistance distribution of each region of the thin-film temperature sensor is obtained.

[0020] Based on the resistance distribution of each region of the thin-film temperature sensor, the temperature field distribution on the surface of the workpiece under test is obtained.

[0021] Preferably, the resistance distribution of each region of the thin-film temperature sensor is obtained based on the voltage distribution at the boundary of the thin-film temperature sensor under a preset current, including:

[0022] Based on the voltage distribution at the boundary of the thin-film temperature sensor under a preset current, the voltage distribution of each region of the thin-film temperature sensor is obtained.

[0023] Based on the voltage distribution in each region of the thin-film temperature sensor, the resistance distribution in each region of the thin-film temperature sensor is obtained.

[0024] Preferably, obtaining the temperature field distribution on the surface of the workpiece under test based on the resistance distribution of each region of the thin-film temperature sensor includes:

[0025] Based on the resistance distribution of each region of the thin-film temperature sensor and the reference resistance of the thin-film temperature sensor, and combined with the RT characteristic curve of the thin-film temperature sensor, the temperature field distribution of the surface of the workpiece to be tested is obtained; the reference resistance is the resistance of the thin-film temperature sensor at the reference temperature.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] The thin-film temperature sensor provided by this invention has high density, good surface quality, strong adhesion to the substrate, and is not easy to fall off. It also exhibits obvious semiconductor characteristics in the range of 0 to 800°C.

[0028] This invention, by adding fillers to the ceramic precursor polyborosilicate, can suppress and compensate for the volume shrinkage of the ceramic precursor during the pyrolysis process, significantly improving the density and surface quality of the material. Preheating and insulating the substrate before spraying the slurry allows the slurry to quickly adhere to the substrate surface after spraying, enabling rapid solvent evaporation. This allows the thin film precursor to quickly and firmly bond with the heterogeneous substrate. After curing and pyrolysis, a high-quality thin-film temperature sensor is obtained, solving the problem of weak bonding and cracking at the interface caused by differences between the thin film and the substrate.

[0029] This invention first fabricates a thin-film temperature sensor on the surface of the workpiece to be tested. By connecting multiple electrodes to different regions of the thin-film temperature sensor surface, the voltage distribution in different regions of the thin-film temperature sensor surface is obtained under a preset current, thus yielding the resistance distribution in the same region. Finally, combining the semiconductor characteristics of the thin-film temperature sensor with its RT characteristic curve, the temperature distribution in different regions of the thin-film temperature sensor surface can be obtained, thereby obtaining the temperature field distribution on the surface of the workpiece to be tested. The temperature field measurement method provided by this invention is based on the semiconductor characteristics of the thin-film temperature sensor. It has no requirements on the material or shape of the workpiece; it only requires fabricating the thin-film temperature sensor on the surface of the workpiece to be tested to measure the temperature field distribution (surface temperature measurement) in real time. This method can meet the temperature field measurement needs of planar, curved, and irregularly shaped workpieces of different materials under high-temperature conditions, providing a highly promising means and method for in-situ online monitoring of the temperature field of high-temperature hot-end components such as aero-engines, large gas turbines, hypersonic vehicles, and rocket propulsion systems. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a physical image of the thin-film temperature sensor provided in Embodiment 1 of the present invention;

[0032] Figure 2 This is the XRD pattern of the thin-film temperature sensor provided in Embodiment 1 of the present invention;

[0033] Figure 3 This is a graph showing the resistance of the thin-film temperature sensor provided in Embodiment 1 of the present invention as a function of temperature.

[0034] Figure 4 This is a physical diagram of the surface electrode distribution of a thin-film temperature sensor provided by the present invention;

[0035] Figure 5 This invention provides a test diagram of the surface electrode distribution and output voltage between electrodes of a thin-film temperature sensor.

[0036] Figure 6 This is a diagram showing the output voltage distribution of the thin-film temperature sensor provided in Embodiment 1 of the present invention at different temperatures;

[0037] Figure 7 This is a resistance distribution cloud map of the thin-film temperature sensor provided in Embodiment 1 of the present invention at different temperatures;

[0038] Figure 8 This is a microscopic image of the thin-film temperature sensor prepared on a SiBCN ceramic substrate according to the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0040] The present invention provides a thin-film temperature sensor in a first aspect, the thin-film temperature sensor having semiconductor properties; the thin-film temperature sensor includes SiBCN ceramic and filler.

[0041] The thin-film temperature sensor provided by this invention has high density, good surface quality, strong adhesion to the substrate, and is not easy to fall off. It also exhibits obvious semiconductor characteristics in the range of 0 to 800°C.

[0042] The present invention provides a second aspect a method for fabricating the thin-film temperature sensor described in the first aspect, the method comprising:

[0043] S1. Mix polyborosilazane, filler and organic solvent to obtain film slurry;

[0044] S2. The thin film slurry is sprayed onto a preheated substrate, cured, and pyrolyzed to obtain a thin film temperature sensor.

[0045] This invention, by adding fillers to the ceramic precursor polyborosilicate, can suppress and compensate for the volume shrinkage of the ceramic precursor during the pyrolysis process, significantly improving the material's density and surface quality. Preheating the substrate before spraying the slurry allows the slurry to quickly adhere to the substrate surface after spraying, enabling rapid solvent evaporation and rapid, firm bonding of the thin-film precursor to the heterogeneous substrate. After curing and pyrolysis, a high-quality thin-film temperature sensor is obtained, solving the problem of weak bonding and cracking at the interface caused by differences between the film and the substrate. Furthermore, the inventors discovered that without the addition of active fillers, the prepared film is prone to cracking during pyrolysis, and the excessively high initial resistance of the material results in no response when current is applied, failing to meet temperature measurement requirements.

[0046] According to some preferred embodiments, the polyborosilazane comprises 50-70 wt% (e.g., 50 wt%, 55 wt%, 60 wt%, 65 wt%, or 70 wt%) and the active filler comprises 30-50 wt% (e.g., 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%) based on the total mass of the polyborosilazane and the filler.

[0047] According to some preferred embodiments, the organic solvent accounts for 40-60% of the total mass of the polyborosilazane and filler (e.g., 40%, 45%, 50%, 55% or 60%).

[0048] The inventors discovered that if the amount of active filler is too small, the viscosity of the slurry is too low, and it cannot form effective adhesion to the substrate surface after spraying. If the amount of active filler is too large, it will lead to uneven filler dispersion, easily clogging the nozzle. Even if it can be sprayed, due to the excessive filler, some small particles will remain on the film surface after curing, becoming crack initiation sources and leading to film cracking and peeling. In addition, if the amount of organic solvent is too small, it will lead to uneven filler dispersion and excessively high slurry viscosity, making it difficult to spray. If the amount of organic solvent is too large, the slurry is too thin and the viscosity is too low, making it difficult to form a dense film. Therefore, this invention controls the amount of polyborosilazane, active filler, and organic solvent within the above ranges to ensure the obtaining of a high-performance thin-film sensor.

[0049] According to some preferred embodiments, the filler is selected from at least one of active fillers and inert fillers; the active filler is preferably at least one of Al, B, Cr, W, Nb, Mo, Si, Ti, V, CrSi2, MoSi2, TiSi2, and TiB2; the inert filler is preferably at least one of SiO2, Al2O3, Zr2O3, Y2O3, SiC, B4C, Si3N4, and BN. The present invention allows for selection of filler types according to requirements.

[0050] According to some preferred embodiments, the organic solvent is xylene.

[0051] According to some preferred embodiments, the preheating temperature is 80–100°C (e.g., 80°C, 85°C, 90°C, 95°C, or 100°C). This invention preheats and insulates the substrate before spraying, allowing the slurry to adhere quickly to the substrate surface after spraying, enabling rapid solvent evaporation, and resulting in a high-quality film that is less prone to cracking after curing and pyrolysis. The inventors found that direct spraying onto a substrate at room temperature (without preheating) resulted in significant film detachment after pyrolysis. Therefore, the process of preheating and insulating the substrate before spraying effectively overcomes the problem of poor interfacial bonding between the film and the substrate.

[0052] According to some preferred embodiments, the curing is carried out in a flowing argon atmosphere at a curing temperature of 300–400°C; and / or

[0053] According to some preferred embodiments, the pyrolysis is carried out in a flowing argon atmosphere at a pyrolysis temperature of 1000–1200°C (e.g., 800°C, 850°C, 900°C, 950°C, or 1000°C). The present invention allows for selection of the pyrolysis temperature to obtain SiBCN ceramic thin films based on the required initial resistance; the lower the pyrolysis temperature, the higher the initial resistance value of the obtained thin film.

[0054] In a second aspect, the present invention provides a method for measuring a temperature field, implemented using the thin-film temperature sensor described in the first aspect, comprising the following steps:

[0055] A thin-film temperature sensor is fabricated on the surface of the workpiece to be tested, and multiple electrodes are connected to the boundary positions of the thin-film temperature sensor to obtain the voltage distribution at the boundary of the thin-film temperature sensor under a preset current. Specifically: First, a thin-film temperature sensor is fabricated on the surface of the workpiece to be tested. Then, according to the shape of the workpiece, multiple electrodes are set at the boundary positions of the thin-film temperature sensor. Using ERT technology, based on the adjacent excitation-relative measurement mode, a preset constant current is applied, and the output voltage data between each pair of electrodes is obtained, thus obtaining the voltage distribution at the boundary of the thin-film temperature sensor under the preset current. It should be noted that the boundary position of the thin-film temperature sensor refers to the edge position of the thin-film temperature sensor. If the workpiece to be tested has a planar structure (e.g., square, circular, other polygonal, etc.), then the boundary position of the thin-film temperature sensor is the boundary position (edge ​​position) of the planar structure. If the thin-film temperature sensor has a curved surface structure (e.g., hemispherical, other irregular curved surface, etc.), then the boundary position of the thin-film temperature sensor is the boundary position (edge ​​position) of the curved surface structure.

[0056] Based on the voltage distribution at the boundary of the thin-film temperature sensor under a preset current, the resistance distribution of each region of the thin-film temperature sensor is obtained; including: (1) Based on the voltage distribution at the boundary of the thin-film temperature sensor under a preset current, the voltage distribution of each region of the thin-film temperature sensor is obtained; specifically: based on the voltage distribution data at the boundary of the thin-film temperature sensor under a preset current, the voltage distribution in the middle of the thin-film temperature sensor can be obtained, and then the voltage distribution of each region of the thin-film temperature sensor can be obtained. (2) Based on the voltage distribution of each region of the thin-film temperature sensor, the resistance distribution of each region of the thin-film temperature sensor is obtained; specifically: based on the preset relationship between constant current, voltage and resistance, the resistance distribution of each region of the thin-film temperature sensor can be obtained from the voltage distribution of each region of the thin-film temperature sensor.

[0057] It should be noted that for the workpiece under test with a curved surface structure, the geometry of the bonding interface between the thin film temperature sensor and the curved surface structure is mapped to a two-dimensional plane. Using the voltage distribution (voltage data) of the thin film temperature sensor boundary under the preset current, the resistance tomography algorithm is used to reconstruct the resistance distribution after the curved surface interface is mapped to a two-dimensional plane. The reconstructed resistance distribution is then mapped back to the curved surface structure to obtain the resistance distribution of each region of the thin film temperature sensor on the surface of the curved surface structure.

[0058] Based on the resistance distribution of each region of the thin-film temperature sensor, the temperature field distribution of the workpiece surface is obtained. This includes: obtaining the temperature field distribution of the workpiece surface based on the resistance distribution of each region of the thin-film temperature sensor and the reference resistance of the thin-film temperature sensor, combined with the RT characteristic curve of the thin-film temperature sensor; the reference resistance is the resistance of the thin-film temperature sensor at a reference temperature, preferably 100℃. Because the thin-film temperature sensor has semiconductor characteristics, the relationship between resistance and temperature can be obtained according to the RT characteristic curve of the thin-film temperature sensor. The temperature of different regions of the thin-film temperature sensor can be obtained from the resistance values ​​of different regions of the thin-film temperature sensor, and thus the temperature distribution of each region of the thin-film temperature sensor can be obtained, thereby obtaining the temperature field distribution of the workpiece surface.

[0059] The temperature field measurement method provided by this invention is based on the semiconductor characteristics of thin-film temperature sensors. It has no requirements regarding the material and shape of the workpiece; it only requires fabricating the thin-film temperature sensor on the surface of the workpiece to measure the temperature field distribution on the workpiece surface in real time (surface temperature measurement). This method can meet the temperature field measurement needs of planar, curved, and irregularly shaped workpieces of different materials under high-temperature conditions, providing a highly promising means and method for in-situ online monitoring of the temperature field of high-temperature hot-end components such as aero-engines, large gas turbines, hypersonic vehicles, and rocket propulsion systems. By measuring the temperature field distribution in real time, abnormal local temperatures can be located promptly, and corresponding countermeasures can be taken. Furthermore, this temperature field measurement method can also be applied to the research and development design stage of high-temperature hot-end components, allowing for structural design based on the temperature field distribution on the surface of the component to avoid localized temperature anomalies; or it can be used to verify the rationality of the component's structural design.

[0060] To more clearly illustrate the technical solution and advantages of the present invention, the present invention will be further described below with reference to embodiments. The present invention does not specifically limit the source of the reagents used in the embodiments and comparative examples; they can be directly purchased or synthesized in-house.

[0061] Example 1

[0062] S1. Mix the polyborosilazane precursor liquid, active filler TiB2, and organic solvent (xylene) in a mass ratio of 3:2:3, and stir with a magnetic stirrer for 90 min to obtain a thin film slurry;

[0063] S2. The substrate (Al2O3 substrate) was preheated at 100℃ for 3 min. Then, the thin film slurry was sprayed onto the preheated substrate using a spray gun with an electrically controlled air pump. After spraying, it was cured at 350℃ for 2 h and finally pyrolyzed at 1000℃ for 6 h. Both curing and pyrolysis were carried out under a flowing argon atmosphere to obtain a high-quality thin film temperature sensor.

[0064] Example 2

[0065] S1. Mix the polyborosilazane precursor liquid, active filler TiB2, and organic solvent (xylene) in a mass ratio of 1:1:1, and stir with a magnetic stirrer for 90 min to obtain a thin film slurry;

[0066] S2. The substrate (Al2O3 substrate) was preheated at 80℃ for 6 minutes. Then, the thin film slurry was sprayed onto the preheated substrate using a spray gun with an electrically controlled air pump. After spraying, it was cured at 350℃ for 2 hours and finally pyrolyzed at 1100℃ for 6 hours. Both curing and pyrolysis were carried out in a flowing argon atmosphere to obtain a high-quality thin film temperature sensor.

[0067] Example 3

[0068] S1. Mix the polyborosilazane precursor liquid, active filler TiB2, and organic solvent (xylene) in a mass ratio of 7:3:4, and stir with a magnetic stirrer for 90 min to obtain a thin film slurry;

[0069] S2. The substrate (Al2O3 substrate) was preheated at 90℃ for 4 min. Then, the thin film slurry was sprayed onto the preheated substrate using a spray gun with an electrically controlled air pump. After spraying, it was cured at 350℃ for 2 h and finally pyrolyzed at 1200℃ for 6 h. Both curing and pyrolysis were carried out under a flowing argon atmosphere to obtain a high-quality thin film temperature sensor.

[0070] It should be noted that the thin-film temperature sensors obtained in Examples 1-3 of the present invention are similar in appearance and performance, and will not be described in detail here. The technical solution of the present invention will be further explained below using Example 1 as an example.

[0071] A physical image of the thin-film temperature sensor prepared in Embodiment 1 of the present invention is shown below. Figure 1 As shown, the surface of the thin-film temperature sensor is flat and the thickness is uniform. It should be noted that the present invention also uses the above method to fabricate a thin-film temperature sensor on the curved surface of an Al2O3 ceramic cylinder, which also yields a high-quality thin-film temperature sensor.

[0072] The XRD pattern of the thin-film temperature sensor prepared in Example 1 of this invention is shown below. Figure 2 As shown, the SiBCN ceramic film without the addition of active filler TiB2 is a typical amorphous SiBCN ceramic. In the thin film temperature sensor prepared by this invention, TiB2 exists in the thin film in a crystalline state.

[0073] This invention investigated the relationship between the resistance of the thin-film temperature sensor prepared in Example 1 and temperature. It was found that the resistance of the thin-film temperature sensor decreases as the ambient temperature increases, exhibiting semiconductor characteristics. Its RT characteristic curve is shown below. Figure 3 As shown.

[0074] This invention utilizes the large-area, high-temperature semiconductor characteristics of the fabricated thin-film temperature sensor. The thin-film temperature sensor exhibits different resistivities at different temperatures (100℃, 200℃, 300℃). The ERT method is employed to arrange electrodes at the geometric boundaries of the fabricated thin-film temperature sensor, apply current excitation to the electrodes, and measure the corresponding voltage signals. Simultaneously, an optimization method is used to reconstruct the resistance distribution, thereby measuring the relative resistance values ​​(resistance distribution) of different regions on the thin-film surface. It should be noted that the electrodes (platinum wire or nickel wire) on the surface of the thin-film temperature sensor can be bonded to the film surface after the film has cured using the slurry used to prepare the thin-film temperature sensor as an adhesive, and then pyrolyze together with the film. Alternatively, the electrodes (platinum wire or nickel wire) can be bonded to the film surface after the thin-film temperature sensor is fabricated. The adhesive material used for bonding the electrodes is selected according to the test temperature; the adhesive material can be graphite conductive adhesive or high-temperature resistant tape. The specific method for testing the resistance distribution of a thin-film temperature sensor in different regions at each temperature (100℃, 200℃, 300℃) is as follows: An ERT method is used to arrange 16 electrodes at the boundary of the thin-film temperature sensor, resulting in a wire layout that can be used for ERT inversion of the temperature field (see the physical diagram of the electrode distribution). Figure 4 Select the measurement mode for adjacent excitation-relative measurement: In the first group of operations, press... Figure 5 As shown, a constant DC current I (0.1mA) is applied to the object under test through adjacent electrodes 1 and 2. Electrode 2 is the input current, and electrode 1 is the output current and grounded. Voltage data (U3-4, U3-5, U3-6, U3-7, U3-8, U3-9, U3-10, U3-11, U3-12, U3-13, U3-14, U3-15, U3-16) are collected between electrodes 3 and 4, 3 and 5, ..., and 3 and 16, for a total of 13 data points. In the second group of operations, a constant DC current I, the same as in the first group, is applied to the object under test through adjacent electrodes 2 and 3. Electrode 3 receives the input current, and electrode 2 outputs the current and is grounded. Following a similar sequence to the first group of operations, 13 data points are obtained. Finally, by traversing all 16 electrodes, a total of 13*16=208 sets of output voltage data can be obtained. The output voltage distribution of the thin-film temperature sensor at different temperatures (100℃, 200℃, 300℃) is shown below. Figure 6 As shown. By Figure 6It can be seen that under different constant temperatures, the output voltage distribution patterns (shapes) of each region are similar, differing only in the magnitude of the voltage values. This means that if, for the same thin-film temperature sensor, the output voltage distribution pattern of a certain region changes, it can be assumed that the change is caused by the temperature of that region, indicating that the temperature of that region is abnormal compared to other regions. Furthermore, based on the output voltage data and constant DC current, the resistance distribution of each region of the thin-film temperature sensor can be obtained, forming a resistance distribution cloud map (e.g., ...). Figure 7 (where (a) corresponds to 100℃, (b) corresponds to 200℃, and (c) corresponds to 300℃). Figure 7 It can be seen that the color of the central region of the thin-film temperature sensor is similar and relatively uniform, meaning that the resistance values ​​in the central region of the thin-film temperature sensor do not differ significantly. This indicates that the thin-film temperature sensor prepared by this invention has good uniformity. It should be noted that... Figure 7 The color difference at the edge is significant compared to the center area. The large difference in resistance is due to the electrodes being placed at the boundary of the thin-film temperature sensor. Electrodes placed at the boundary are susceptible to the influence of "contact resistance" and the technical limitations of the ERT method itself. The resistance image fluctuates significantly at the boundary of the electrode connection. It is generally believed that the error in the boundary area is large and is usually not considered.

[0075] This invention measures the surface temperature field of a workpiece by using a fabricated thin-film temperature sensor, and includes the following steps:

[0076] (1) First, a thin film temperature sensor is prepared on the surface of the workpiece to be tested. Then, according to the shape of the workpiece to be tested, multiple electrodes are set at the boundary position of the thin film temperature sensor. Then, a constant current is passed through, and the output voltage data between the two electrodes is obtained respectively, that is, the voltage distribution of the thin film temperature sensor boundary under the preset current is obtained.

[0077] (2) Based on the voltage distribution at the boundary of the thin film temperature sensor under the preset current, the voltage distribution of each region of the thin film temperature sensor is obtained; based on the voltage distribution of each region of the thin film temperature sensor, the resistance distribution of each region of the thin film temperature sensor is obtained.

[0078] (3) Based on the resistance distribution of each region of the thin film temperature sensor and the reference resistance of the thin film temperature sensor, and combined with the RT characteristic curve of the thin film temperature sensor, the temperature field distribution of the surface of the workpiece to be tested is obtained; the reference resistance is the resistance of the thin film temperature sensor at the reference temperature.

[0079] This invention also fabricated a thin-film temperature sensor on a SiBCN ceramic substrate (homogeneous substrate). The fabrication method was the same as in Example 1, and high-quality thin-film temperature sensors were obtained in both cases. Figure 8 As shown. From Figure 8As can be seen in (a), the surface of the SiBCN ceramic matrix exhibits numerous small particles and an uneven texture under an optical microscope. The surface of the material actually contains many micro-cracks and pores, indicating that the surface quality of the SiBCN ceramic matrix after pyrolysis is not very good. Figure 8 As can be seen in (b), the surface of the thin film temperature sensor prepared by spraying, curing and pyrolysis of thin film slurry is relatively uniform and no cracks occur. The unevenness and excessive particle feel of the material surface are greatly improved, which preliminarily verifies that the prepared film has good density.

[0080] In summary, the method for fabricating thin-film temperature sensors provided by this invention can produce high-quality thin-film temperature sensors on both homogeneous and heterogeneous substrates. Using the thin-film temperature sensor provided by this invention, temperature field measurement of workpieces made of different materials can be realized under high-temperature conditions, meeting the application needs of temperature field measurement in different fields.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of making a thin film temperature sensor, characterized by, The preparation method comprises: S1. mixing polysilazane, fillers and an organic solvent to obtain a thin film slurry; S2. spraying the thin film slurry on a substrate after preheating treatment, and curing and cracking to obtain a thin film temperature sensor; The polysilazane accounts for 50-70 wt% and the fillers account for 30-50 wt% based on the total mass of the polysilazane and the fillers; The organic solvent accounts for 40-60% of the total mass of the polysilazane and the fillers; The fillers are active fillers and comprise at least one of Al, B, Cr, W, Nb, Mo, Si, Ti, V, CrSi2, MoSi2, TiSi2 and TiB2; The organic solvent is dimethylbenzene; The preheating treatment temperature is 80-100℃; The curing is performed under a flowing argon atmosphere, and the curing temperature is 300-400℃; The cracking is performed under a flowing argon atmosphere, and the cracking temperature is 1000-1200℃.

2. A thin film temperature sensor characterized by, The thin film temperature sensor is prepared by the preparation method of claim 1.

3. A method of temperature field measurement, characterized by, The thin film temperature sensor of claim 2 is achieved by comprising the following steps: Preparation of a thin film temperature sensor on the surface of a workpiece to be measured, and connection of multiple electrodes at the boundary position of the thin film temperature sensor to obtain the voltage distribution of the boundary of the thin film temperature sensor under a preset current; Based on the voltage distribution of the boundary of the thin film temperature sensor under the preset current, the resistance distribution of each region of the thin film temperature sensor is obtained; Based on the resistance distribution of each region of the thin film temperature sensor, the temperature field distribution of the surface of the workpiece to be measured is obtained.

4. The temperature field measurement method according to claim 3, characterized in that, Based on the voltage distribution of the boundary of the thin film temperature sensor under the preset current, the resistance distribution of each region of the thin film temperature sensor is obtained, comprising: Based on the voltage distribution of the boundary of the thin film temperature sensor under the preset current, the voltage distribution of each region of the thin film temperature sensor is obtained; Based on the voltage distribution of each region of the thin film temperature sensor, the resistance distribution of each region of the thin film temperature sensor is obtained.

5. The temperature field measurement method according to claim 3, characterized by, Based on the resistance distribution of each region of the thin film temperature sensor, the temperature field distribution of the surface of the workpiece to be measured is obtained, comprising: Based on the resistance distribution of each region of the thin film temperature sensor and the reference resistance of the thin film temperature sensor, and in combination with the R-T characteristic curve of the thin film temperature sensor, the temperature field distribution of the surface of the workpiece to be measured is obtained; the reference resistance is the resistance of the thin film temperature sensor at a reference temperature.

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