Temperature sensing array based on fabric type flexibility, preparation method and spinning solvent

Abstract

The invention belongs to the technical field of thermal protection materials, and provides a temperature sensing array based on fabric type flexibility, a preparation method and a spinning solvent. The preparation method comprises the following steps: S1, forming a polymer precursor through a spinning forming process to obtain an initial fiber; s2, performing twisting forming on the initial fibers to form twisted fibers; s3, the twisted fibers are subjected to curing treatment and pyrolysis treatment, and sensing yarn is obtained; s4, the sensing yarn is integrated on the flexible ceramic fiber cloth, and the flexible ceramic fiber cloth with the sensing array ceramic temperature-sensitive yarn is obtained; s5, performing laser local heating on the wire connection position of the sensing array to prepare a conductive electrode; and S6, selecting a wiring mode according to the conductivity and the target test temperature, and identifying a real-time temperature field according to the temperature resistance characteristic. Array integration of the woven thermal protection material can be realized through a weaving process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of thermal protection materials, and particularly relates to a fabric-type flexible temperature sensing array, a preparation method and a spinning solvent. BACKGROUND

[0002] The flexible thermal protection material based on ceramic fiber fabric has great application potential in the thermal protection system of a high-speed variable geometry aircraft. In the intelligent flight process with continuous change of the high-speed aircraft configuration, the coupling constraint conditions of high-temperature environment and large deformation of the aircraft put forward urgent demands for a new concept of flexible temperature sensor. The temperature sensors used in the existing hypersonic aircraft are all rigid structures with large volume and embedded type, which cannot meet the structural integrity and reliability requirements of the flexible thermal protection system. The temperature-sensitive material based on special polymers can meet the large deformation conditions, but cannot withstand the extreme thermal load environment in the high-speed flight process. Therefore, it is urgent to develop a new concept of flexible temperature sensing material and integrated method suitable for high-speed flight environment. SUMMARY

[0003] The application aims to solve the technical problems in the prior art, and provides a fabric-type flexible temperature sensing array, a preparation method and a spinning solvent. The preparation method obtains a flexible sensing yarn that can be woven by combining a spinning forming process and a twisting forming process, and realizes array integration of the woven thermal protection material through a weaving process.

[0004] To achieve the above technical purposes, the application adopts the following technical solutions: A preparation method of a fabric-type flexible temperature sensing array, comprising the following steps: S1, forming a polymer precursor through a spinning forming process to obtain an initial fiber; S2, twisting the initial fiber to form a twisted fiber; S3, sequentially performing solidification treatment and pyrolysis treatment on the twisted fiber to obtain a sensing yarn; S4, integrating the sensing yarn on a flexible ceramic fiber cloth according to a preset weaving distance and a preset yarn distance to obtain a flexible ceramic fiber cloth with sensing array ceramic temperature-sensitive yarns; S5, laser local heating is performed on the lead connection position of the sensing array to prepare a conductive electrode; S6, according to the electrical conductivity of the ceramic temperature-sensitive yarn and the target test temperature, a wiring mode is selected, and the real-time temperature field can be tested according to the temperature-resistance characteristics of the ceramic temperature-sensitive yarn.

[0005] Optionally, before step S1, a spinning solvent is prepared, and the spinning solvent is added when the polymer precursor is formed through the spinning forming process.

[0006] Optionally, in step S1, the polymer precursor is one of polycarbosilane, polysilazane and polyborosilazane.

[0007] Optionally, in step S1, the spinning forming process is one of air flow spinning, electrospinning and conjugate spinning.

[0008] Optionally, the spinning forming process is electrospinning, and the specific parameters include: the voltage is a kilovolt, the spinning distance ranges from [b, c], and vacuum drying treatment is performed at d degrees Celsius after spinning is completed.

[0009] Optionally, in step S3, the treatment mode for curing treatment is curing the polymer precursor, removing the spinning solvent, and the curing temperature ranges from [alpha, beta] degrees Celsius, and the curing temperature holding time ranges from [gamma, mu].

[0010] Optionally, in step S3, the pyrolysis treatment mode is pyrolysis twisting fiber, and the treatment parameters include: the pyrolysis temperature ranges from g degrees Celsius to k degrees Celsius, and the pyrolysis temperature gradient is at least one of g degrees Celsius, h degrees Celsius, i degrees Celsius, j degrees Celsius and k degrees Celsius in sequence, wherein g < h < i < j < k.

[0011] Optionally, in step S4, the weaving distance is p millimeters, and the yarn distance is q millimeters.

[0012] Optionally, in step S6, the wiring mode is one of 2-wire system or 4-wire system.

[0013] The application further provides a fabric-type flexible temperature sensing array prepared by the fabric-type flexible temperature sensing array preparation method as described above, which comprises ceramic temperature sensitive yarn and flexible ceramic fiber cloth, and the ceramic temperature sensitive yarn is obtained by weaving the sensing yarn array on the flexible ceramic fiber cloth. The sensing yarn is made by a spinning forming process and a twisting forming process, and comprises a sensing area arranged in the middle and a conductive area arranged at both ends.

[0014] The application further provides a spinning solvent suitable for the fabric-type flexible temperature sensing array preparation method as described above, and the preparation process of the spinning solvent specifically comprises: Trichloromethane and N,N-dimethylformamide are prepared into a mixed solvent in a mass ratio of 1:3, 10% by mass of polyvinylpyrrolidone, 20% by mass of polysilazane and 70% by mass of the mixed solvent are mixed, and magnetic stirring is performed for 5 hours to obtain the spinning solvent.

[0015] Compared with the prior art, the application has the following beneficial effects: (1) The application obtains flexible sensing yarn that can be woven by combining a spinning forming process and a twisting forming process; (2) The flexible sensing yarn obtained by the application can realize array integration of the woven type heat protection material through the weaving process, realize the close combination of the flexible sensing array and the heat protection material through the preset weaving distance and the preset yarn distance, realize the array integration of the sensing, expand from a single temperature point to a temperature field, and ensure the integrity and reliability of the heat protection system; (3) The application combines the polymer precursor with the high-temperature pyrolysis process, so that the sensing yarn can withstand the extreme thermal load environment in the high-speed flight process, overcoming the defects that the traditional temperature sensor cannot meet the flexible heat protection, and overcoming the defect that the temperature-sensitive material based on the special polymer cannot withstand the extreme thermal load environment in the high-speed flight process; (4) The application heats the wire connection position of the sensing array by laser local heating technology to prepare the wire electrode, overcomes the thermal damage of the traditional welding process to the flexible ceramic fiber, and at the same time adapts to different conductivity yarns by using different wiring methods, improves the stability and precision of signal acquisition in high temperature environment; (5) The application can fully exert the excellent formability of the flexible ceramic, has the characteristics of high temperature resistance, oxidation resistance, high temperature sensing, etc., realizes the preparation of the temperature-sensitive yarn by combining the spinning forming process and the twisting forming process, and obtains the fabric type flexible heat protection material with the sensing array by using the weaving process; (6) The application can realize the effective mixing of polysilazane and polyvinylpyrrolidone by using the mixed solvent prepared from chloroform and N,N-dimethylformamide, and further improve the spinning forming capacity. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The flow chart of the fabric type flexible temperature sensing array preparation method of the embodiment of the application; Figure 2 The micro-morphology of the ceramic temperature-sensitive yarn of the embodiment of the application; Figure 3 The high temperature conductivity test curve of the ceramic temperature-sensitive yarn of the embodiment of the application; Figure 4 The laser local heating schematic diagram of the ceramic temperature-sensitive yarn of the embodiment of the application; Figure 5 The flexible ceramic fiber cloth schematic diagram with the sensing array ceramic temperature-sensitive yarn of the embodiment of the application.

[0017] Explanation of the attached drawings: 1, ceramic temperature-sensitive yarn; 11, sensing area; 12, conductive area; 2, flexible ceramic fiber cloth; 3, wire. DETAILED DESCRIPTION

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 Combination Figure 1 As shown, this embodiment of the invention provides a method for fabricating a flexible temperature sensing array based on fabric, including the following steps: S1. The polymer precursor is shaped into initial fibers through a spinning process; S2. Twist the initial fibers to form twisted fibers; S3. The twisted fibers are sequentially subjected to curing and pyrolysis treatments to obtain the sensing yarn; S4. Integrate the sensing yarns on the flexible ceramic fiber cloth according to the preset weaving distance and preset yarn distance to obtain a flexible ceramic fiber cloth with sensing array ceramic temperature-sensitive yarns. S5. Locally heat the wire connection points of the sensor array with laser to prepare conductive electrodes; S6. Select the wiring method according to the conductivity of the ceramic temperature-sensitive yarn and the target test temperature. The real-time temperature field can be tested based on the temperature resistance characteristics of the ceramic temperature-sensitive yarn.

[0020] Example 2 Combination Figure 1 As shown, this embodiment of the invention provides a method for fabricating a flexible temperature sensing array based on fabric, including the following steps: S1. The polymer precursor is shaped into initial fibers through a spinning process; S2. Twist the initial fibers to form twisted fibers; S3. The twisted fibers are sequentially subjected to curing and pyrolysis treatments to obtain the sensing yarn; S4. Integrate the sensing yarns on the flexible ceramic fiber cloth according to the preset weaving distance and preset yarn distance to obtain a flexible ceramic fiber cloth with sensing array ceramic temperature-sensitive yarns. S5. Locally heat the wire connection points of the sensor array with laser to prepare conductive electrodes; S6. Select the wiring method according to the conductivity of the ceramic temperature-sensitive yarn and the target test temperature. The real-time temperature field can be tested based on the temperature resistance characteristics of the ceramic temperature-sensitive yarn. Specifically, testing the conductivity and thermal resistance characteristics of ceramic temperature-sensitive yarns is an existing technology, which will not be elaborated on here. The target test temperature can be set based on expert experience.

[0021] Further, before step S1, a spinning solvent is prepared, and the spinning solvent is added when the polymer precursor is subjected to the spinning forming process.

[0022] Embodiment 3 In this embodiment, on the basis of embodiment 2, the polymer precursor in step S1 is one of polycarbosilane, polysilazane and polyborosilazane. Specifically, the polymer precursor can also be modified, for example, polysilazane can be further modified by molecular design, such as adding Zr source, and the system changes from SiCN to SiCNZrO after cracking; the modified polymer precursor is mainly a polymer precursor containing Zr and Al elements, as long as it can meet the characteristics of high temperature resistance and sensing; The spinning forming process in step S1 is selected from one of air spinning, electrospinning and conjugate spinning. Specifically, the air spinning and electrospinning can be first used for spinning film forming, and then further twisted into a shape, and the conjugate spinning can be directly twisted into a shape. As a preferred mode, the spinning forming process is electrospinning, and the specific parameters include: the voltage is a kilovolts, the spinning distance range is [b, c], and the vacuum drying treatment is carried out at d degrees Celsius after spinning is completed. Specifically, the voltage value is a=15kV, the spinning distance range [b, c] is [10, 20] cm, and the vacuum drying treatment temperature value is d=80℃.

[0023] Embodiment 4 In this embodiment, on the basis of embodiment 2, in step S3, the treatment mode for curing treatment is to cure the polymer precursor and remove the spinning solvent, and the curing temperature range is [α, β] degrees Celsius, and the curing temperature holding time is [γ, μ]; specifically, the curing temperature range [α, β] is [150, 350] degrees Celsius, and the curing temperature is preferably 350℃, and the curing temperature holding time range [γ, μ] is [1, 3] hours, and the curing temperature holding time is preferably 2 hours. As a preferred mode, in step S3, the pyrolysis treatment mode is pyrolysis twisted fiber, and the treatment parameters include: the pyrolysis temperature range is g degrees Celsius to k degrees Celsius, and the pyrolysis temperature gradient is set to at least one of g degrees Celsius, h degrees Celsius, i degrees Celsius, j degrees Celsius and k degrees Celsius in turn, wherein g Specifically, g=1000℃, h=1100℃, i=1200℃, j=1300℃, k=1400℃; different pyrolysis temperatures correspond to different conductivities, which affect the final sensitivity (i.e. the conductivity response per unit temperature), and when the temperature exceeds 1450℃, the material begins to decompose, so the above pyrolysis temperature gradient is selected, and by setting the pyrolysis temperature gradient, the temperature sensing array can meet the demand of different conductivities, and has stronger adaptability.

[0024] Embodiment 5 In this embodiment, based on embodiment 2, in step S4, the weaving distance is p millimeters, and the yarn distance is q millimeters. Specifically, the weaving distance is p=5mm, and the yarn distance is q=10mm. The flexible ceramic fiber cloth can be selected from an alumina fiber cloth or a SiC fiber cloth (silicon carbide fiber cloth); the ceramic temperature-sensitive yarn obtained from the SiC fiber cloth is a SiCN ceramic temperature-sensitive yarn. Figure 2 As shown in the microstructure of the ceramic temperature-sensitive yarn, as shown in the microstructure of the ceramic temperature-sensitive yarn, Figure 3 As shown in the microstructure of the ceramic temperature-sensitive yarn, as shown in the microstructure of the ceramic temperature-sensitive yarn,

[0025] In step S5, after the laser local heating of the lead connection position of the sensing array, the prepared conductive electrode has high conductivity. As a preferred mode, in step S6, the wiring mode is one of 2-wire system or 4-wire system; specifically, when the conductivity of the ceramic temperature-sensitive yarn is low, the 2-wire system can be selected for wiring to facilitate wiring; when the conductivity of the ceramic temperature-sensitive yarn is high, the 4-wire system is selected for wiring to improve the precision. Embodiment 6 As shown in the microstructure of the ceramic temperature-sensitive yarn, as shown in the microstructure of the ceramic temperature-sensitive yarn, Figures 4-5 As shown in the microstructure of the ceramic temperature-sensitive yarn, as shown in the microstructure of the ceramic temperature-sensitive yarn, The sensing yarn is made by a spinning forming process and a twisting forming process, and includes a sensing area 11 arranged in the middle and a conductive area 12 arranged at both ends; specifically, the sensing area 11 is used for monitoring the temperature, and the conductive area 12 is used for connecting with the lead 3.

[0026] Embodiment 7 The spinning solvent is suitable for the preparation method of the fabric-type flexible temperature sensing array, and the preparation process of the spinning solvent specifically includes: The chloroform and N,N-dimethylformamide are prepared into a mixed solvent with a mass ratio of 1:3, 10% by mass of polyvinylpyrrolidone, 20% by mass of polysilazane, and 70% by mass of the mixed solvent are mixed, and magnetic stirring is performed for 5 hours to obtain a spinning solvent; By using chloroform and N,N-dimethylformamide to prepare a mixed solvent, the effective mixing of polysilazane and polyvinylpyrrolidone can be achieved, and the spinning forming capacity is improved.

[0027] The following is an example: Example 1 The chloroform and DMF (N,N-dimethylformamide) are prepared into a mixed solvent with a mass ratio of 1:3, the mixed solvent, polysilazane, and polyvinylpyrrolidone (PVP) are mixed, and magnetic stirring is performed for 5 hours to obtain a spinning solvent; the mass fraction of the mixed solvent accounts for 70%; the mass fraction of polysilazane accounts for 20%, and the mass fraction of polyvinylpyrrolidone (PVP) accounts for 10%; Example 2 The chloroform and DMF (N,N-dimethylformamide) are prepared into a mixed solvent with a mass ratio of 1:3, the mixed solvent, polysilazane, and polyvinylpyrrolidone (PVP) are mixed, and magnetic stirring is performed for 5 hours to obtain a spinning solvent; the mass fraction of the mixed solvent accounts for 52%; the mass fraction of polysilazane accounts for 32%, and the mass fraction of polyvinylpyrrolidone (PVP) accounts for 16%; Example 3 The chloroform and DMF (N,N-dimethylformamide) are prepared into a mixed solvent with a mass ratio of 1:3, the mixed solvent, polysilazane, and polyvinylpyrrolidone (PVP) are mixed, and magnetic stirring is performed for 5 hours to obtain a spinning solvent; the mass fraction of the mixed solvent accounts for 73%; the mass fraction of polysilazane accounts for 18%, and the mass fraction of polyvinylpyrrolidone (PVP) accounts for 9%; The final result is that the fiber quality obtained in Example 1 is the best, is more dense, and has higher fiber uniformity; in Example 2, the high content of PVP leads to poorer fiber integrity and more surface pores after pyrolysis treatment; and in Example 3, the low content of PVP is not conducive to the formation of fibers.

[0028] The above only describes the embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, and improvement within the scope of the present application should be included in the protection scope of the present application.

Claims

1. A method for fabric-based flexible temperature sensor array fabrication, comprising: The method comprises the following steps: S1, forming a polymer precursor by a spinning forming process to obtain an initial fiber; S2, twisting the initial fiber to form a twisted fiber; S3, sequentially performing solidification treatment and pyrolysis treatment on the twisted fiber to obtain a sensing yarn; S4, integrating the sensing yarn on a flexible ceramic fiber cloth according to a preset weaving distance and a preset yarn distance to obtain a flexible ceramic fiber cloth with a sensing array ceramic temperature-sensitive yarn; S5, laser local heating is performed on the lead connection position of the sensing array to prepare a conductive electrode; S6, according to the electrical conductivity of the ceramic temperature-sensitive yarn and the target test temperature, the wiring mode is selected, and according to the temperature resistance characteristics of the ceramic temperature-sensitive yarn, the real-time temperature field can be tested.

2. The fabric-based flexible temperature sensing array preparation method of claim 1, wherein, Before step S1, a spinning solvent is prepared, and the spinning solvent is added when the polymer precursor is formed by the spinning forming process.

3. The fabric-based flexible temperature sensing array preparation method of claim 2, wherein, In step S1, the polymer precursor is one of polycarbosilane, polysilazane and polyborosilazane.

4. The fabric-based flexible temperature sensing array preparation method of claim 2, wherein, In step S1, the spinning forming process selects one of air flow spinning, electrospinning and conjugate spinning.

5. The fabric-based flexible temperature sensing array preparation method of claim 4, wherein, The spinning forming process is electrospinning, and the specific parameters include: the voltage is a kilovolt, the spinning distance range is [b, c], and the spinning is completed, and then vacuum drying treatment is performed at d degrees Celsius.

6. The fabric-based flexible temperature sensing array preparation method of claim 2, wherein, In step S3, the solidification treatment is performed by solidifying the polymer precursor and removing the spinning solvent, and the solidification temperature range is [α, β] degrees Celsius, and the solidification temperature holding time range is [γ, μ].

7. The fabric-based flexible temperature sensing array preparation method of claim 2, wherein, In step S3, the pyrolysis treatment is performed by pyrolyzing the twisted fiber, and the treatment parameters include: the pyrolysis temperature range is g degrees Celsius to k degrees Celsius, and the pyrolysis temperature gradient is sequentially set to at least one of g degrees Celsius, h degrees Celsius, i degrees Celsius, j degrees Celsius and k degrees Celsius, wherein g 8. The fabric-based flexible temperature sensing array preparation method of claim 2, wherein, In step S4, the weaving distance is p millimeters, and the yarn distance is q millimeters.

9. The fabric-based flexible temperature sensing array preparation method of claim 8, wherein, In step S6, the wiring mode is one of 2-wire system or 4-wire system.

10. A fabric-based flexible temperature sensing array, characterized by, Prepared by the fabric-based flexible temperature sensing array preparation method according to any one of claims 1-9, comprising a ceramic temperature-sensitive yarn and a flexible ceramic fiber cloth, the ceramic temperature-sensitive yarn is woven on the flexible ceramic fiber cloth through a sensing yarn array; The sensing yarn is made by a spinning forming process and a twisting forming process, comprising a sensing area arranged in the middle and a conductive area arranged at both ends.

11. A spinning solvent, characterized in that, The spinning solvent preparation process is suitable for the fabric-based flexible temperature sensing array preparation method according to any one of claims 2-9, and the spinning solvent preparation process specifically comprises: A mixed solvent is prepared by mixing chloroform and N,N-dimethylformamide in a mass ratio of 1:3, 10% by mass of polyvinylpyrrolidone, 20% by mass of polysilazane and 70% by mass of the mixed solvent are mixed, and magnetic stirring is performed for 5 hours to obtain the spinning solvent.

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