A method for assembling a silicon nitride ceramic radome

Abstract

The present invention discloses a method for assembling a silicon nitride ceramic radome, comprising the following steps: preparing an adhesive, wherein the adhesive comprises an adhesive component A and an adhesive component B; pretreating the silicon nitride ceramic radome; pretreating a quartz fiber cloth with the adhesive to obtain a connecting quartz fiber cloth; connecting the pretreated silicon nitride ceramic radome and a pretreated connecting ring with the connecting quartz fiber cloth to assemble the silicon nitride ceramic radome, thereby achieving high bonding strength when the radome and the metal ring are assembled and connected without reducing the thermal insulation performance and wave transmission performance of the silicon nitride ceramic radome.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna cover processing, and in particular to a method for assembling a silicon nitride ceramic antenna cover. Background Art

[0002] At present, with the development of aerospace industry, the performance requirements of the materials used in missile radomes are getting higher and higher, and silicon nitride has become a highly valued ceramic material.

[0003] However, due to its own characteristics, the porous silicon nitride material has low bonding strength with metal connectors and cannot meet the mechanical properties of the product components; and because the silicon nitride ceramic antenna cover has a high porosity, when the antenna cover and the metal ring are connected by adhesive during bonding, the adhesive can easily penetrate into the silicon nitride pores, resulting in reduced thermal insulation and wave transmission performance of the antenna cover.

[0004] Therefore, how to achieve high bonding strength when the antenna cover and the metal ring are assembled and connected without affecting the thermal insulation and wave transmission properties of the silicon nitride ceramic antenna cover has become a difficult problem that needs to be overcome urgently in this field. Summary of the Invention

[0005] The purpose of the present invention is to achieve high bonding strength when the antenna cover and the metal ring are assembled and connected, and to avoid the problem of reduced thermal insulation and wave transmission performance of the silicon nitride ceramic antenna cover. A method for assembling a silicon nitride ceramic antenna cover is provided, comprising the following steps: preparing an adhesive, the adhesive comprising an adhesive component A and an adhesive component B; pretreating the silicon nitride ceramic antenna cover; pretreating quartz fiber cloth with the adhesive to obtain quartz fiber cloth for connection; connecting the pretreated silicon nitride ceramic antenna cover and the pretreated connecting ring with the connecting quartz fiber cloth to achieve assembly of the silicon nitride ceramic antenna cover, achieving high bonding strength when the antenna cover and the metal ring are assembled and connected, and not reducing the thermal insulation and wave transmission performance of the silicon nitride ceramic antenna cover.

[0006] To achieve the above-mentioned object, the present invention provides a method for assembling a complex silicon nitride ceramic radome, comprising the following steps: preparing a silicon nitride ceramic radome, wherein the silicon nitride ceramic radome includes a radome connection surface and a radome non-connection surface; preparing an adhesive, wherein the adhesive includes an adhesive component A and an adhesive component B; and pretreating the silicon nitride ceramic radome;

[0007] The quartz fiber cloth is pretreated with the adhesive to obtain a quartz fiber cloth for connection; the connection surface of the connecting ring is pretreated; the pretreated silicon nitride ceramic antenna cover and the pretreated connecting ring are connected with the quartz fiber cloth for connection to realize the assembly of the silicon nitride ceramic antenna cover; preferably, the connecting ring is a metal connecting ring, and further preferably, the connecting ring is a low-expansion Invar alloy steel connecting ring.

[0008] Compared with the prior art, the technical solution of the present invention has the beneficial effect that, because the adhesive comprises adhesive component A and adhesive component B, the adhesive can achieve high connection strength between the silicon nitride radome and the connecting ring. At the same time, the connection strength between the silicon nitride ceramic radome and the connecting ring can be further increased as the ambient temperature rises during the use of the silicon nitride ceramic radome.

[0009] By pre-treating the silicon nitride ceramic radome, the silicon nitride ceramic radome is facilitated to be firmly connected to the metal ring, and at the same time, it is facilitated to prevent the adhesive from penetrating into the interior of the silicon nitride ceramic;

[0010] By pre-treating the quartz fiber cloth with the adhesive, a high connection strength between the silicon nitride antenna cover and the metal ring is achieved, and the low connection strength caused by the unevenness after the silicon nitride ceramic antenna cover and the connecting ring are connected is avoided; at the same time, it is beneficial to avoid the adhesive from entering the internal pores of the silicon carbide ceramic, resulting in reduced thermal insulation and wave transmission performance of the antenna cover; and it is beneficial for the antenna cover to be ceramicized and densified with part of the fiber cloth and the adhesive during use, thereby further increasing the connection strength with the silicon nitride ceramic antenna cover.

[0011] Furthermore, the binder component A includes phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber; the mass ratio of the phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber is 100:100:(1.3~2.1):(7.5~10):(89~91):(52~54).

[0012] The beneficial effect of adopting the above-mentioned further technical solution is that, by virtue of the adhesive component A including phenol and formaldehyde, the adhesive has high bonding strength; by virtue of the adhesive component A including nano-Al2O3 powder and silsesquioxane, the adhesive has high bonding strength, and at the same time, during the use of the antenna cover, part of the adhesive is ceramicized and densified, thereby improving the connection strength with the silicon nitride ceramic antenna cover; by virtue of the adhesive component A including nitrile rubber, it is further beneficial to improve the connection strength and connection toughness; by virtue of the adhesive component A including ethyl acetate, the fluidity of the adhesive is adjusted.

[0013] Furthermore, the binder component A is prepared by the following steps: weighing phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber according to a mass ratio; mixing the phenol, formaldehyde, and nano-Al2O3 powder and performing a prepolymerization reaction; wherein the prepolymerization reaction time is 3 to 5 hours and the prepolymerization reaction temperature is 100 to 110°C; after the prepolymerization reaction is completed, silsesquioxane is added for a secondary polymerization reaction, and then ethyl acetate is added to prepare a phenolic resin solution; and nitrile rubber is added to the phenolic resin solution to obtain the binder component A.

[0014] The specific process of the secondary polymerization is to perform reduced pressure distillation at a temperature of 100-110° C. and a vacuum degree of 0.01 MPa for 2-3 hours; then perform reduced pressure distillation when the temperature drops to 90° C., and then add ethyl acetate to obtain a phenolic resin solution.

[0015] The beneficial effect of adopting the above-mentioned further technical solution is that, by performing a prepolymerization reaction and then adding silsesquioxane for a secondary polymerization reaction, the molecular weight of the phenolic resin in the binder is concentrated, thereby avoiding the problem of excessive viscosity of the phenolic resin caused by too high a molecular weight, thereby avoiding the problem of too high an amount of solvent added to the binder component A, and avoiding the problem of reduced bonding strength of the binder caused by too low a molecular weight; by adding silsesquioxane to the binder, while achieving a strong bonding strength of the binder A, it is beneficial to densify and ceramicize some components in the binder during use of the silicon nitride radome, and to strengthen the bonding strength of the silicon nitride ceramic radome;

[0016] The pressure distillation during the secondary polymerization process is beneficial for making the molecular weight of the binder component A substantially consistent.

[0017] Furthermore, the binder component B includes ceramic powder; the ceramic powder includes one or more of silicon carbide powder, silicon carbide whiskers, and mica.

[0018] The beneficial effect of adopting the above further technical solution is that, by including ceramic powder in the adhesive component B, some components in the adhesive are densified and ceramicized during use of the silicon nitride ceramic antenna cover, and the connection strength of the silicon nitride ceramic antenna cover is enhanced.

[0019] Furthermore, the binder component B further includes metal powder, and the metal powder includes one or more of titanium carbide, titanium aluminum carbide, hafnium carbide, and iron oxide.

[0020] The beneficial effect of adopting the above-mentioned further technical solution is that, because the adhesive component B also includes metal powder, during the use of the silicon nitride antenna cover, due to the increase in external environmental temperature, some components in the adhesive are densified and ceramicized. At the same time, the connection strength between the metal component in the adhesive and the metal connecting ring is increased, which is further conducive to further increasing the connection strength between the silicon nitride antenna cover and the metal ring.

[0021] Furthermore, the adhesive is formed by mixing adhesive component A and adhesive component B, wherein the mass ratio of the adhesive component A to the adhesive component B is 1:(1-1.5).

[0022] The beneficial effect of adopting the above-mentioned further technical solution is that, while achieving high bonding strength between the silicon nitride ceramic antenna cover and the metal connecting ring through the adhesive, the connection strength between some components in the adhesive and the silicon nitride antenna cover and the metal connecting ring is increased during use.

[0023] Furthermore, the silicon nitride ceramic radome pretreatment process includes: performing a protective treatment on the non-connecting surface of the radome, preferably the non-connecting surface of the radome is protected by covering, and performing a polishing treatment on the connecting surface of the radome, wherein the polishing treatment is performed in a negative pressure environment; in the negative pressure environment, air flows from the non-connecting surface of the radome to the connecting surface of the radome;

[0024] The polished radome connection surface is cleaned with anhydrous ethanol or ethyl acetate and allowed to stand; then the radome connection surface is coated with adhesive component A and allowed to stand for 20 to 30 minutes before use;

[0025] and / or

[0026] The pretreatment of the connecting surface of the connecting ring includes: cleaning the connecting surface of the connecting ring with ethyl acetate and then performing sandblasting roughening treatment; cleaning and drying the connecting surface of the connecting ring after sandblasting roughening with anhydrous ethanol; after drying, applying a silane coupling agent to the connecting surface of the connecting ring, and then drying it for standby use; wherein the drying temperature is 120-150°C and the drying time is 40-60 minutes.

[0027] The beneficial effect of adopting the above-mentioned further technical solution is that the connection surface of the silicon nitride ceramic radome is conducive to connection, while avoiding affecting the non-connection surface of the silicon nitride ceramic radome during the pretreatment process; by coating the connection surface of the radome with adhesive component A and standing it for 20 to 30 minutes, while facilitating the high connection strength between the silicon nitride ceramic radome and the connecting ring, the solvent in the adhesive evaporates before bonding, thereby avoiding the adhesive from entering the internal pores of the silicon nitride ceramic during the connection process between the silicon nitride ceramic radome and the connecting ring, thereby affecting the thermal insulation and wave transmission properties of the radome;

[0028] The specific process of pre-treating the connection surface is beneficial to improving the connection strength between the connection ring and the silicon nitride ceramic antenna cover. Applying silane coupling agent to the connection surface of the connection ring after drying is beneficial to achieving high connection strength between the assembled connection ring and the adhesive.

[0029] Furthermore, the pretreatment process of the quartz fiber cloth by the adhesive includes: impregnating the surface of the quartz fiber cloth with the adhesive; performing a primary heating on the quartz fiber cloth impregnated with the adhesive to remove volatiles;

[0030] The single layer or multiple layers of quartz fiber cloth after the initial heating are subjected to secondary heating and pressurization treatment at the same time to achieve the densification of the quartz fiber cloth, and finally obtain quartz fiber cloth for connection with different thicknesses.

[0031] The beneficial effect of adopting the above-mentioned further technical solution is that the quartz fiber cloth is pretreated by the adhesive, and the silicon nitride ceramic antenna cover and the connecting ring are connected by the connecting quartz fiber cloth, which is beneficial to avoid the problem of the adhesive penetrating into the pores in the silicon nitride ceramic antenna cover caused by directly connecting the silicon nitride ceramic antenna cover and the connecting ring by the adhesive; at the same time, through secondary heating and pressurization treatment, the quartz fiber cloth is densified and quartz fiber cloth of different thicknesses is prepared, avoiding the problem of the silicon nitride ceramic antenna cover and the connecting ring being not tight enough due to the quartz fiber cloth when the silicon nitride ceramic antenna cover is connected to the connecting ring.

[0032] Furthermore, the specific process of connecting the pretreated silicon nitride ceramic antenna cover and the pretreated connecting ring through the connecting quartz fiber cloth is as follows:

[0033] According to the adaptation gap between the connecting ring and the silicon nitride ceramic radome at different assembly positions, quartz fiber cloths of different thicknesses are used for connection to be pre-pasted longitudinally along the inner wall of the pre-treated radome connection surface; the connecting surface of the pre-treated connecting ring is pre-connected with the quartz fiber cloth pre-pasted longitudinally on the inner wall of the radome connection surface. The pre-connection process comprises positioning the connecting surface of the connecting ring and the quartz fiber cloth covering the radome connection surface relative to each other according to preset requirements and maintaining a preset distance; heating three times; after the three heatings, pressing the connecting surface of the connecting ring and the quartz fiber cloth covering the radome connection surface tightly; and then heating four times; preferably, the preset distance is 2-6 cm.

[0034] When pre-bonding quartz fiber cloth of varying thickness longitudinally along the inner wall of the pre-treated radome connection surface, the length of the quartz fiber cloth should extend beyond the bonding surface and to the outer wall below the end face of the silicon nitride ceramic radome. After standing for 1-2 hours, the connection surface of the pre-treated connecting ring and the quartz fiber cloth covering the radome connection surface are pre-bonded. During the pre-bonding process, the quartz fiber cloth on the outside of the silicon nitride ceramic radome assists in securing the connection ring to the silicon nitride ceramic radome, preventing displacement or misalignment of the fiber cloth during the bonding process. Ultimately, this ensures sufficient bonding and uniform gap control. This method also avoids the drawbacks of uneven surfaces associated with traditional fiber cloths, ensuring overall bonding quality.

[0035] or

[0036] The surface of the quartz fiber cloth is impregnated with an adhesive to obtain a connecting quartz fiber cloth, which is directly covered on the connecting surface of the connecting ring; the covering thickness of the connecting quartz fiber cloth exceeds the fitting gap of the connecting surface of the connecting ring by 5 to 10 mm; the surface of the covered connecting ring is then covered with a demoulding cloth and an adhesive-absorbing cloth; the connecting ring is then placed in a vacuum bag and vacuumed for 3 to 5 hours, and the connecting ring is taken out for a primary curing treatment; the bonding surface of the metal ring after the curing treatment is processed and polished; the pre-treated antenna cover and the fiber cloth connecting surface of the connecting ring are coated with an adhesive, and the antenna cover connecting surface and the metal ring are matched and connected, and then a secondary curing treatment is performed.

[0037] The beneficial effect of adopting the above-mentioned further technical solution is that, according to the adaptation gap between the metal ring and the ceramic cover at different assembly positions, quartz fiber cloths of different thicknesses are used for connection to be pre-pasted longitudinally along the inner wall of the pre-treated antenna cover connection surface, which is beneficial to avoid the problem of insufficient tight connection between the silicon nitride ceramic antenna cover and the connecting ring due to the unevenness of the antenna cover connection surface when the silicon nitride ceramic antenna cover is connected to the connecting ring, thereby improving the connection strength; after the three heatings, the connection surface of the connecting ring and the quartz fiber cloth covering the antenna cover connection surface are pressed tightly, and then heated four times to achieve softening of the adhesive after the third heating. At the same time, by maintaining a distance between the silicon nitride ceramic antenna cover and the connecting ring during this process, the problem of volatiles entering the silicon nitride ceramic antenna cover during this process is avoided; and then the adhesive is cured by the fourth heating, thereby achieving connection between the silicon nitride ceramic antenna cover and the connecting ring.

[0038] Furthermore, the specific process of the initial heating is to raise the temperature from room temperature to 40-50°C;

[0039] The specific process of the secondary heating is to raise the temperature to 60-80°C at a heating rate of 8-9°C / min;

[0040] The specific process of the three heatings is to raise the temperature to 60-80°C at a heating rate of 4-5°C / min;

[0041] The specific process of the four heatings is as follows: the highest heating temperature is 170-180°C, the temperature is raised from room temperature to 80°C at a heating rate of 4-5°C / min; the temperature is raised from 80°C to 150°C at a heating rate of 3-4°C / min; the temperature is raised from 150°C to 170-180°C at a heating rate of 2-3°C / min.

[0042] The beneficial effect of adopting the above further technical solution is that the debinding is achieved by heating the room temperature to 40-50°C at a heating rate of 8-9°C / min;

[0043] The specific process of the secondary heating is to raise the temperature to 60-80°C at a heating rate of 8-9°C / min, so as to soften the adhesive and connect the multiple layers of quartz fiber cloth. At the same time, the residual volatiles are quickly volatilized, so that there are larger pores between the multiple layers of quartz fiber cloth. This is conducive to the subsequent volatilization of the volatiles in the adhesive when connecting the silicon nitride ceramic radome and the connecting ring, thereby avoiding the problem of volatiles entering the pores of the silicon nitride ceramic radome.

[0044] The specific process of the three heatings is to raise the temperature to 60-80°C at a heating rate of 4-5°C / min. The heating rate is slow, so that the binder is softened while the aperture of the volatilization channel of the residual volatiles is small, which is conducive to the volatilization of the residual volatiles, thereby preventing the volatiles from entering the interior of the silicon nitride ceramic antenna cover;

[0045] The specific process of the four heatings is as follows: the highest heating temperature is 170-180°C, the temperature is increased from room temperature to 80°C at a rate of 4-5°C / min; the temperature is increased from 80°C to 150°C at a rate of 3-4°C / min; the temperature is increased from 150°C to 180°C at a rate of 2-3°C / min; the adhesive is solidified, and at the same time, the slow heating during the heating process is beneficial to the slow volatilization rate of trace residues in the adhesive and the small aperture of the volatilization channel, which is beneficial to further prevent volatiles from entering the interior of the silicon nitride ceramic antenna cover. DETAILED DESCRIPTION

[0046] In order to better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments.

[0047] Example 1:

[0048] One aspect of the present embodiment provides a method for assembling a complex silicon nitride ceramic radome, comprising the following steps: preparing a silicon nitride ceramic radome, wherein the silicon nitride radome includes a radome connecting surface and a radome non-connecting surface; preparing an adhesive, wherein the adhesive includes an adhesive component A and an adhesive component B; pretreating the silicon nitride ceramic radome; pretreating quartz fiber cloth with the adhesive to obtain quartz fiber cloth for connection; pretreating the connection surface of the connecting ring; connecting the pretreated silicon nitride ceramic radome and the pretreated connecting ring with the connecting quartz fiber cloth to achieve assembly of the silicon nitride ceramic radome.

[0049] The binder component A includes phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber; the mass ratio of the phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber is 100:100:1.8:8.8:90:53.

[0050] In the process of preparing the binder component A, phenol, formaldehyde, and nano-Al2O3 powder are mixed according to a mass ratio, and then a prepolymerization reaction is carried out; the prepolymerization reaction time is 4 hours and the prepolymerization reaction temperature is 105°C; then silsesquioxane is added for a secondary polymerization reaction, and then ethyl acetate is added to prepare a phenolic resin solution; then, nitrile rubber is added in a certain proportion to obtain the binder component A;

[0051] The specific process of the secondary polymerization is to perform reduced pressure distillation at a temperature of 105° C. and a vacuum degree of 0.01 MPa for 2.5 hours; then perform reduced pressure distillation when the temperature drops to 90° C., and then add ethyl acetate to obtain a phenolic resin solution.

[0052] The binder component B further includes metal powder, and the metal powder includes titanium carbide, titanium aluminum carbide, and hafnium carbide;

[0053] The specific process of preparing the adhesive includes mixing the adhesive component A and the adhesive component B in a mass ratio of 1:1.25.

[0054] The specific process of pre-treating the silicon nitride ceramic radome is as follows: the non-connecting surface of the radome is protected by coating, the connecting surface of the radome is polished, and the silicon nitride ceramic radome is placed in a negative pressure environment during the polishing process; in the negative pressure environment, air flows from the non-connecting surface of the radome to the connecting surface of the radome;

[0055] The polished radome connection surface is cleaned with anhydrous ethanol or ethyl acetate and allowed to stand; then the radome connection surface is coated with adhesive component A and allowed to stand for 25 minutes before use;

[0056] The specific process of pre-treating the connection surface of the connecting ring is as follows: cleaning the connection surface of the connecting ring with ethyl acetate and then performing sandblasting to roughen it; then cleaning and drying it with anhydrous ethanol; after drying, applying a silane coupling agent to the connection surface of the connecting ring, and then drying it for standby use; the drying temperature is 135° C. and the drying time is 50 minutes.

[0057] The specific process of pre-treating the quartz fiber cloth with the binder is as follows: impregnating the surface of the quartz fiber cloth with the binder; then heating the quartz fiber cloth to remove volatiles;

[0058] Then, the single-layer or multi-layer quartz fiber cloth is subjected to secondary heating and pressure treatment after the initial heating to achieve densification of the quartz fiber cloth, and finally obtain quartz fiber cloth for connection with different thicknesses.

[0059] The specific process of connecting the pretreated silicon nitride ceramic radome and the pretreated connecting ring through the connecting quartz fiber cloth is as follows:

[0060] Based on the matching gaps between the metal ring and the ceramic cover at different assembly positions, quartz fiber cloths of varying thicknesses are pre-bonded longitudinally along the inner wall of the pre-treated radome connection surface; the connection surface of the pre-treated connection ring is pre-connected to the quartz fiber cloth covering the radome connection surface. The connection process comprises positioning the connection surface of the connection ring and the quartz fiber cloth covering the radome connection surface relative to each other according to preset requirements, while maintaining a preset distance of 5 cm; then heating the connection ring three times; after the three heatings, pressing the connection surface of the connection ring and the quartz fiber cloth covering the radome connection surface tightly; then heating the connection ring four times;

[0061] When pre-bonding quartz fiber cloth of varying thickness along the inner wall of the pre-treated radome connection surface, the length of the quartz fiber cloth extends beyond the bonding surface and to the outer wall below the end face of the silicon nitride ceramic radome. After standing for 1.5 hours, the connection surface of the pre-treated connecting ring and the quartz fiber cloth covering the radome connection surface are pre-bonded. During the pre-bonding process, the quartz fiber cloth on the outside of the silicon nitride ceramic radome assists in securing the connection ring and the silicon nitride ceramic radome, preventing displacement or misalignment of the fiber cloth during the bonding process. Ultimately, this ensures sufficient bonding and uniform gap control. This method also avoids the drawbacks of uneven surfaces of traditional fiber cloth, ensuring overall bonding quality.

[0062] The specific process of the initial heating is to raise the temperature from room temperature to 45°C;

[0063] The specific process of the secondary heating is to heat the temperature to 70°C at a heating rate of 8.5°C / min;

[0064] The specific process of the three heatings is to heat the temperature to 70°C at a heating rate of 4.5°C / min;

[0065] The specific process of the four heatings is as follows: the highest heating temperature is 175°C, the temperature is raised from room temperature to 80°C at a heating rate of 4.5°C / min; the temperature is raised from 80°C to 150°C at a heating rate of 3.5°C / min; and the temperature is raised from 150°C to 180°C at a heating rate of 2.5°C / min.

[0066] The same contents as those in Example 1 are not repeated here. The differences between this embodiment and Example 1 are as follows:

[0067] The connecting ring is a low-expansion Invar alloy steel connecting ring; the adhesive component A includes phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber; the mass ratio of the phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber is 100:100:2:9.5:90:53.

[0068] In the process of preparing the binder component A, phenol, formaldehyde, and nano-Al2O3 powder are mixed according to a mass ratio, and then a prepolymerization reaction is carried out; the prepolymerization reaction time is 3.5 hours, and the prepolymerization reaction temperature is 109°C; then silsesquioxane is added for a secondary polymerization reaction, and then ethyl acetate is added to prepare a phenolic resin solution; then, nitrile rubber is added in a proportion to obtain the binder component A;

[0069] The specific process of the secondary polymerization is to perform reduced pressure distillation at a temperature of 109° C. and a vacuum degree of 0.01 MPa for 2.8 hours; then perform reduced pressure distillation when the temperature drops to 90° C., and then add ethyl acetate to obtain a phenolic resin solution.

[0070] The binder component B further includes metal powder, and the metal powder includes titanium carbide, titanium aluminum carbide, hafnium carbide, and iron oxide;

[0071] The specific process of preparing the adhesive includes mixing the adhesive component A and the adhesive component B in a mass ratio of 1:1.4.

[0072] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, the above-mentioned features may have similar functions to (but not limited to) those disclosed in this application.

Claims

1. A method for assembling a silicon nitride ceramic radome, characterized in that: Including the following step: preparing a binder comprising a binder component A and a binder component B; pre-treating the silicon nitride ceramic radome; The quartz fiber cloth is pretreated with the adhesive to obtain the quartz fiber cloth for connection. fiber cloth; Pre-processing the connection surface of the connection ring; Connecting the pretreated silicon nitride ceramic radome and the pretreated connecting ring via the connecting quartz fiber cloth to achieve assembly of the silicon nitride ceramic radome; The binder is formed by mixing a binder component A and a binder component B, wherein the mass ratio of the binder component A to the binder component B is 1:(1-1.5); The binder component A includes phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber; the mass ratio of the phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber is 100:100: (1.3-2.1): (7.5-10): (89-91): (52-54); The binder component B further includes metal powder, and the metal powder includes one or more of titanium carbide, titanium aluminum carbide, hafnium carbide, and iron oxide; The binder component A is prepared by the following steps: Weigh phenol, formaldehyde, nano-Al2O3 powder, silsesquioxane, ethyl acetate, and nitrile rubber according to mass ratio; Phenol, formaldehyde and nano-Al2O3 powder are mixed to carry out a prepolymerization reaction, wherein the prepolymerization reaction time is 3 to 5 hours and the prepolymerization reaction temperature is 100 to 110°C; After the prepolymerization reaction is completed, silsesquioxane is added to carry out a secondary polymerization reaction, and then ethyl acetate is added to prepare a phenolic resin solution; Adding nitrile rubber to the phenolic resin solution to obtain a binder component A; The binder component B includes ceramic powder; The ceramic powder includes one or more of silicon carbide powder, silicon carbide whiskers, and mica.

2. The method for assembling a silicon nitride ceramic radome according to claim 1, wherein: The pretreatment process of the silicon nitride ceramic radome includes: Performing protective treatment on the non-connected surface of the radome; Grinding the connection surface of the radome, wherein the grinding is performed in a negative pressure environment; in the negative pressure environment, air flows from the non-connection surface of the radome to the connection surface of the radome; Clean the polished radome connection surface with anhydrous ethanol or ethyl acetate; then apply adhesive component A to the radome connection surface and let it stand for 20 to 30 minutes before use; and / or The pre-processing of the connection surface of the connection ring includes: The connecting surface of the connecting ring is cleaned with ethyl acetate and then roughened by sandblasting; Use anhydrous ethanol to clean and dry the connection surface of the connection ring that has been roughened by sandblasting; After drying, a silane coupling agent is applied to the connecting surface of the connecting ring, and then dried for standby use. The drying temperature is 120-150° C. and the drying time is 40-60 minutes.

3. The method for assembling a silicon nitride ceramic radome according to claim 1, wherein: The pretreatment process of the quartz fiber cloth by the binder includes: Impregnating the surface of the quartz fiber cloth with a binder; The quartz fiber cloth impregnated with the binder is initially heated to remove volatiles; The single layer or multiple layers of quartz fiber cloth after the initial heating are subjected to secondary heating and pressurization to achieve the densification of the quartz fiber cloth, and finally obtain quartz fiber cloth for connection with different thicknesses.

4. The method for assembling a silicon nitride ceramic radome according to claim 3, wherein: The specific process of connecting the pretreated silicon nitride ceramic radome and the pretreated connecting ring through the connecting quartz fiber cloth is as follows: According to the adaptation gap between the connecting ring and the silicon nitride ceramic radome at different assembly positions, quartz fiber cloths of different thicknesses are used for connection to be pre-pasted longitudinally along the inner wall of the pre-treated radome connection surface; Pre-connecting the connection surface of the pre-treated connection ring to the inner wall of the connection surface of the radome with the connection quartz fiber cloth pre-pasted longitudinally, wherein the pre-connection process comprises: placing the connection surface of the connection ring and the quartz fiber cloth covering the connection surface of the radome relative to each other according to preset requirements and maintaining a preset distance; Perform three heating steps; After heating three times, the connecting surface of the connecting ring and the quartz fiber cloth covering the connecting surface of the radome are pressed tightly; Then four heatings were performed.

5. The method for assembling a silicon nitride ceramic radome according to claim 4, wherein: The specific process of the initial heating is to raise the temperature from room temperature to 40-50°C; The specific process of the secondary heating is to raise the temperature to 60-80°C at a heating rate of 8-9°C / min; The specific process of the three heatings is to raise the temperature to 60-80°C at a heating rate of 4-5°C / min; The specific process of the four heatings is as follows: heating from room temperature to 80°C at a heating rate of 4-5°C / min; heating from 80°C to 150°C at a heating rate of 3-4°C / min; and heating from 150°C to 170-180°C at a heating rate of 2-3°C / min.