A composite thermal insulation material with wave-absorbing performance, a multilayer phase interface structure comprising the composite thermal insulation material and a preparation method thereof

Abstract

The application discloses a composite heat insulation material with wave absorption performance, a multilayer phase interface structure containing the composite heat insulation material and a preparation method of the multilayer phase interface structure; the composite heat insulation material comprises: a heat insulation material and a wave absorber, wherein the heat insulation material is yttrium zirconium oxide YSZ powder; the wave absorber is samarium iron nitride SmFeN powder; the mass ratio of the heat insulation material to the wave absorber is 1:1; the multilayer phase interface structure containing the composite heat insulation material comprises: a YSZ / SmFeN uniform mixing structure, an interface structure parallel to incident electromagnetic waves, an interface structure vertical to the incident electromagnetic waves and a periodic arrangement interface structure containing both the interface vertical to the incident electromagnetic waves and the interface parallel to the incident electromagnetic waves.

Description

Technical Field

[0001] This invention relates to the field of microwave absorbing materials technology, and in particular to a composite thermal insulation material with microwave absorbing properties, a multilayer phase interface structure containing the composite thermal insulation material, and a method for preparing the same. Background Technology

[0002] With the rapid development of radar detection technology, the demand for radar stealth in hot components such as aircraft engines and military shells is becoming increasingly strong. Commonly used heat insulation materials, such as YSZ (YZrO yttrium zirconium oxide), have weak radar absorption properties. Although they can simultaneously possess heat insulation and radar absorption properties after being uniformly mixed with materials such as SmFeN, the reflectivity results still cannot achieve the performance of broadband and high strength.

[0003] Therefore, providing a method to enhance the wave absorption effect of thermal insulation materials is a problem that urgently needs to be solved. Summary of the Invention

[0004] In view of this, the present invention discloses a composite thermal insulation material with wave absorption properties, a multilayer phase interface structure containing the composite thermal insulation material, and a method for preparing the same.

[0005] The technical solution of the present invention includes: on the one hand, the present invention provides a composite thermal insulation material with wave-absorbing properties, comprising: a thermal insulation material and a wave-absorbing agent, wherein the thermal insulation material is yttrium zirconium oxide (YSZ) powder with a spherical structure having an average diameter of 1 nm-70 μm; the wave-absorbing agent is samarium iron nitrogen (SmFeN) powder with a sheet-like structure having an average particle size of 10 nm-70 μm; the mass ratio of the thermal insulation material to the wave-absorbing agent is 1:1.

[0006] Secondly, the present invention provides a multilayer phase interface structure comprising the composite thermal insulation material, including: a uniformly mixed YSZ / SmFeN structure, an interface structure parallel to the incident electromagnetic wave, an interface structure perpendicular to the incident electromagnetic wave, and a periodically arranged interface structure that simultaneously includes an interface perpendicular to the incident electromagnetic wave and an interface parallel to the incident electromagnetic wave.

[0007] Preferably, the interface structure parallel to the incident electromagnetic wave includes one YSZ / SmFeN parallel to the incident electromagnetic wave interface and two YSZ / SmFeN / YSZ parallel to the incident electromagnetic wave interface.

[0008] The interface structure perpendicular to the incident electromagnetic wave includes: one YSZ / SmFeN perpendicular to the incident electromagnetic wave interface; two YSZ / SmFeN / YSZ and SmFeN / YSZ / SmFeN perpendicular to the incident electromagnetic wave interface; three YSZ / SmFeN / YSZ / SmFe perpendicular to the incident electromagnetic wave interface; and four YSZ / SmFeN / YSZ / SmFeN / YSZ perpendicular to the incident electromagnetic wave interface.

[0009] The interface structure includes a periodic arrangement that is both perpendicular to and parallel to the incident electromagnetic wave interface.

[0010] Finally, the present invention also provides a method for preparing the multilayer phase interface structure, comprising: taking equal masses of YSZ powder and SmFeN powder, uniformly mixing them with paraffin on a heating stage at 80°C, and then pouring the mixture into a coaxial mold for extrusion molding to obtain a YSZ / SmFeN mixed coaxial ring structure, wherein the mass ratio of YSZ powder to SmFeN powder and the mass ratio of SmFeN powder to paraffin is 7:3.

[0011] Preferably, the method includes: taking equal masses of YSZ powder and SmFeN powder, mixing them uniformly with paraffin wax on a heating table at 80°C, and then pouring the mixture into a coaxial mold for extrusion molding to obtain YSZ coaxial ring structure and SmFeN coaxial ring structure respectively, wherein the mass ratio of YSZ powder and SmFeN powder to paraffin wax is 7:3.

[0012] The YSZ coaxial ring structure and the SmFeN coaxial ring structure are cut proportionally and spliced ​​together to form a complete coaxial ring structure. The structure is then placed in a coaxial mold and extruded to obtain a YSZ / SmFeN structure containing one parallel to the incident electromagnetic wave interface and a YSZ / SmFeN / YSZ structure containing two parallel to the incident electromagnetic wave interface.

[0013] The proportional cutting is to ensure that the mass of YSZ and SmFeN are equal.

[0014] Preferably, the method includes: taking equal masses of YSZ powder and SmFeN powder, mixing them uniformly with paraffin wax on a heating table at 80°C, and then pouring the mixture into a coaxial mold for extrusion molding to obtain YSZ coaxial ring structure and SmFeN coaxial ring structure respectively, wherein the mass ratio of YSZ powder and SmFeN powder to paraffin wax is 7:3.

[0015] The YSZ coaxial ring structure and the SmFeN coaxial ring structure are stacked layer by layer and placed in a coaxial mold for fixing and shaping, respectively forming YSZ / SmFeN with one perpendicular to the incident electromagnetic wave interface; YSZ / SmFeN / YSZ and SmFeN / YSZ / SmFeN with two perpendicular to the incident electromagnetic wave interface; YSZ / SmFeN / YSZ / SmFeN with three perpendicular to the incident electromagnetic wave interface; and YSZ / SmFeN / YSZ / SmFeN with four perpendicular to the incident electromagnetic wave interface.

[0016] Preferably, the method includes: taking equal masses of YSZ powder and SmFeN powder, mixing them uniformly with paraffin wax on a heating table at 80°C, and then pouring the mixture into a coaxial mold for extrusion molding to obtain YSZ coaxial ring structure and SmFeN coaxial ring structure respectively, wherein the mass ratio of YSZ powder and SmFeN powder to paraffin wax is 7:3.

[0017] The YSZ coaxial ring structure and the SmFeN coaxial ring structure are cut proportionally, spliced ​​left and right to form a complete coaxial sample, and then stacked top to bottom. The sample is then placed in a mold to form a periodically arranged interface structure that simultaneously includes interfaces perpendicular to and parallel to the incident electromagnetic wave interface.

[0018] This invention provides a method for preparing a multilayer phase interface structure with microwave absorption properties. The resulting material has good broadband microwave absorption properties, and the preparation method is low in cost, simple in structure, and easy in process.

[0019] Specifically, the present invention also includes the following beneficial effects;

[0020] 1. Wideband absorption performance: By designing different phase interfaces and relatively uniform mixing groups, the effective absorption bandwidth in the range of 2-18 GHz is significantly increased, with the widest effective absorption bandwidth reaching 8.54 GHz.

[0021] 2. Improved reflection loss: The reflection loss value can be effectively reduced by designing different phase interfaces, with the minimum reflection loss value being -53.244dB.

[0022] 3. Low manufacturing cost: Compared with other microwave absorbing materials, the manufacturing process of this composite thermal insulation material is relatively low, making large-scale manufacturing feasible.

[0023] 4. Versatility: The multi-layer phase interface structure of this material can be adjusted and optimized according to requirements, making it suitable for various application fields, including aerospace, military, and communications.

[0024] 5. Simple engineering: The preparation process is relatively simple and easy to expand and adapt to different application needs.

[0025] 6. Electromagnetic wave stealth: It can effectively reduce electromagnetic wave reflection and improve electromagnetic wave stealth performance, making it suitable for applications that require low observability.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the present invention. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 These are schematic diagrams of different phase interface structures provided in the embodiments of the present invention;

[0030] Figure 2 SEM image of SmFeN powder provided in the embodiments of the present invention;

[0031] Figure 3 SEM image of YSZ powder provided in the embodiments of the present invention;

[0032] Figure 4 Projection plots of reflection loss RL values ​​for different models provided in the embodiments of the present invention at 2-18 GHz. Detailed Implementation

[0033] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of systems consistent with some aspects of the invention as detailed in the appended claims.

[0034] This implementation scheme is based on the fact that at the interface of materials with different electromagnetic parameters, the polarization ability of the material itself can be enhanced under the presence of an electromagnetic field, thereby increasing dielectric polarization loss and thus strengthening electromagnetic absorption. Therefore, this implementation scheme enhances the wave absorption effect of the thermal insulation material by appropriately constructing the interface between the thermal insulation material and the wave absorber.

[0035] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0036] Example 1

[0037] The composite heat-insulating and microwave-absorbing material with a multi-layered phase interface structure and its preparation method provided by the present invention include the following steps:

[0038] Prepare the required materials: yttrium zirconium oxide (YSZ) powder and samarium iron nitrogen (SmFeN) powder. The specific compositions are shown in Tables 1 and 2, respectively. Figure 2 It can be seen that SmFeN has a sheet-like structure with an average size of 100 μm * 80 μm. (From...) Figure 3 It can be seen that YSZ has a spherical structure with an average diameter of 70 μm.

[0039] Table 1 SmFeN alloy content

[0040]

[0041] Table 2 YSZ ceramic powder content

[0042]

[0043] YSZ powder and SmFeN powder were mixed evenly at a mass ratio of 1:1.

[0044] The mixed powder of YSZ and SmFeN was mixed with paraffin wax at a mass ratio of 7:3 on a heating plate at 80°C until the paraffin wax melted and the mixed powder was evenly distributed. The mixed sample was poured into a coaxial mold and extruded to form a coaxial ring sample, awaiting measurement. The measurement is as follows: Figure 1 As shown in S1.

[0045] The dielectric constant and permeability were obtained by measuring with a vector network analyzer (Agilent PNA N5320C) and coaxial measurement method (ASTM 5568), and the reflection loss value was obtained by calculation.

[0046] Example 2

[0047] An interface parallel to the incident electromagnetic wave is constructed based on the composite thermal insulation material of Example 1, including:

[0048] Q1: Equal masses of YSZ, SmFeN, and paraffin wax are extruded into coaxial ring samples at a mass ratio of 7:3. Two coaxial samples are then cut proportionally and joined together to form an interface parallel to the incident electromagnetic wave. The ring samples are then placed in a mold to form a coaxial ring sample, awaiting measurement. A schematic diagram of the model measurement is shown below. Figure 1 As shown in S2.

[0049] Q2: Two coaxial samples are cut proportionally and joined side-by-side to create two interfaces parallel to the incident electromagnetic wave. These are then placed in a mold to form a coaxial ring sample. A schematic diagram of the model measurement is shown below. Figure 1 As shown in S3.

[0050] Example 3

[0051] Based on the composite thermal insulation material of Example 1, an interface perpendicular to the incident electromagnetic wave is constructed, including:

[0052] Q1: Equal masses of YSZ, SmFeN, and paraffin wax were extruded into coaxial ring samples at a mass ratio of 7:3. These samples were then stacked and reshaped to form a coaxial ring sample S4 with an interface perpendicular to the incident electromagnetic wave. A schematic diagram of the model measurement is shown below. Figure 1 Shown in S4.

[0053] Q2: The layers are stacked and reshaped to form a coaxial ring sample with two interfaces perpendicular to the incident electromagnetic wave, i.e., SmFeN / YSZ / SmFeN stacking. The sample is then placed in a mold to form a coaxial ring. A schematic diagram of the measurement model is shown below. Figure 1 As shown in S5.

[0054] Q3: The layers are stacked and reshaped to form a YSZ / SmFeN / YSZ stacking configuration with two interfaces perpendicular to the incident electromagnetic wave. This is then placed in a mold to form a coaxial ring sample. A schematic diagram of the model is shown below. Figure 1 As shown in S6.

[0055] Q4: The layers are stacked and reshaped to form a coaxial ring sample with three interfaces perpendicular to the incident electromagnetic wave. The sample is then placed in a mold to form a model, as shown in the schematic diagram below. Figure 1 As shown in S7.

[0056] Q5: The layers are stacked and reshaped to form a coaxial ring sample with four interfaces perpendicular to the incident electromagnetic wave. The schematic diagram of the model is shown below. Figure 1 As shown in S8.

[0057] Example 4

[0058] Based on the composite thermal insulation material of Example 1, a periodic interface is constructed, including:

[0059] Equal masses of YSZ and SmFeN were extruded with paraffin wax at a mass ratio of 7:3 to form coaxial ring samples. First, the coaxial samples were cut proportionally and spliced ​​side-by-side to form a complete coaxial sample, then stacked vertically. Finally, the samples were placed in a mold to form coaxial ring samples. A schematic diagram of the model is shown below. Figure 1 As shown in S9.

[0060] The high-temperature microwave absorption performance of the microwave absorbing materials obtained in Examples 1-4 was determined. The method is as follows:

[0061] The dielectric constant and permeability were obtained using a vector network analyzer (Agilent PNA N5320C) and coaxial measurement methods (ASTM 5568), and the reflection loss value was calculated as follows: Figure 4 As shown in Table 3, the reflection loss values ​​for samples S1-S9 are presented, along with the minimum reflection loss (RL), effective absorption range (RL < -10dB), and effective absorption bandwidth for different models. The results show that the minimum reflection loss (RL)... min The effective absorption bandwidth (EAB, RL < -10dB) is two important factors for evaluating microwave absorption performance. The minimum reflection loss of the homogeneous hybrid S1 is -39.097dB, and the EAB is 1.3492GHz. It can be seen that although homogeneous hybridization provides absorption capability, the effective absorption bandwidth is small and concentrated in the mid-to-high frequency range. The minimum reflection loss of a single parallel interface (S2) is -42.757dB, which improves absorption at low frequencies, and the EAB is 1.0794GHz. The minimum reflection loss of two parallel interfaces S5 is -30.774dB, and the EAB is 2.725GHz. It can be seen that adding a parallel interface increases the minimum reflection loss, but widens the EAB.

[0062] With a single vertical interface (S3), the minimum reflection loss is -54.498 dB, and the effective bandwidth at high frequencies is wider. Having two vertical interfaces, S5 and S6, with interfaces of YSZ / SmFeN / YSZ, significantly improves absorption performance, particularly RL. min The absorption loss can reach -53.244dB, with an EAB of 8.5453GHz. The minimum reflection loss of the three vertical interfaces S7 is -36.584dB with an EAB of 2.518GHz, while the minimum reflection loss of the four vertical interfaces S8 is -38.056dB with an EAB of 3.95GHz. The effective absorption bandwidth of S9 is 7.3859-8.9151GHz. This indicates that having both interfaces perpendicular and parallel to the incident electromagnetic wave shifts the effective absorption range to lower frequencies, thus increasing the absorption effect at low frequencies. Comparing the different groups, the single-layer interface with an interface parallel to the incident electromagnetic wave performs best; when there is an interface perpendicular to the incident electromagnetic wave, the two vertical interfaces of type YSZ / SmFeN / YSZ show the best absorption performance.

[0063] Table 3. Minimum reflection loss (RL), effective absorption range (RL < -10dB), and effective absorption bandwidth for different models.

[0064]

[0065] In summary, this invention significantly improves wave absorption by constructing effective interfaces with different structures. The method for preparing the wave-absorbing material provided in this application is simple, feasible, and can be produced continuously with low production costs. The wave-absorbing material prepared by this method has a wide effective absorption bandwidth, low reflection loss, and stable wave absorption performance, and can obtain a composite material with heat insulation and wave absorption properties.

[0066] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

Claims

1. A multilayer phase interface structure comprising a composite thermal insulation material with wave-absorbing properties, characterized in that, The composite thermal insulation material comprises: thermal insulation material and microwave absorbing agent, wherein the thermal insulation material is yttrium zirconium oxide (YSZ) powder with a spherical structure having an average diameter of 1 nm-70 μm; the microwave absorbing agent is samarium iron nitrogen (SmFeN) powder with a sheet-like structure having an average particle size of 10 nm-70 μm; the mass ratio of the thermal insulation material to the microwave absorbing agent is 1:

1. The multi-layer phase interface structure of the composite thermal insulation material includes: an interface structure perpendicular to the incident electromagnetic wave. The interface structure perpendicular to the incident electromagnetic wave includes either one YSZ / SmFeN perpendicular to the incident electromagnetic wave interface or two YSZ / SmFeN / YSZ perpendicular to the incident electromagnetic wave interface.

2. A multilayer phase interface structure comprising a composite thermal insulation material with wave-absorbing properties, characterized in that, The composite thermal insulation material comprises: thermal insulation material and microwave absorbing agent, wherein the thermal insulation material is yttrium zirconium oxide (YSZ) powder with a spherical structure having an average diameter of 1 nm-70 μm; the microwave absorbing agent is samarium iron nitrogen (SmFeN) powder with a sheet-like structure having an average particle size of 10 nm-70 μm; the mass ratio of the thermal insulation material to the microwave absorbing agent is 1:

1. The multi-layered phase interface structure of the composite thermal insulation material includes: a periodically arranged interface structure that simultaneously comprises interfaces perpendicular to and parallel to the incident electromagnetic wave interface. .

3. The method for preparing the multilayer phase interface structure as described in claim 1, characterized in that, include: Equal masses of YSZ powder and SmFeN powder were taken and mixed evenly with paraffin wax on a heating table at 80°C. After mixing, the mixture was poured into a coaxial mold and extruded to obtain YSZ coaxial ring structure and SmFeN coaxial ring structure respectively. The mass ratio of YSZ powder to paraffin wax was 7:

3. The YSZ coaxial ring structure and the SmFeN coaxial ring structure are stacked layer by layer and placed in a coaxial mold for fixing and shaping, respectively reshaping into YSZ / SmFeN containing one interface perpendicular to the incident electromagnetic wave or YSZ / SmFeN / YSZ containing two interfaces perpendicular to the incident electromagnetic wave.

4. The method for preparing the multilayer phase interface structure as described in claim 2, characterized in that, include: Equal masses of YSZ powder and SmFeN powder were taken and mixed evenly with paraffin wax on a heating table at 80°C. After mixing, the mixture was poured into a coaxial mold and extruded to obtain YSZ coaxial ring structure and SmFeN coaxial ring structure respectively. The mass ratio of YSZ powder to paraffin wax was 7:

3. The YSZ coaxial ring structure and the SmFeN coaxial ring structure are cut proportionally, spliced ​​left and right to form a complete coaxial sample, and then stacked top to bottom. The sample is then placed in a mold to form a periodically arranged interface structure that simultaneously includes interfaces perpendicular to and parallel to the incident electromagnetic wave interface. .

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