SiCf / SiC composite material cladding tube-end plug welding part of glass ceramic welding seam and preparation method and application thereof

Abstract

The invention belongs to the technical field of welding, and discloses a SiCf / SiC composite material cladding tube-end plug welding part of a glass ceramic welding seam and a preparation method and application of the SiCf / SiC composite material cladding tube-end plug welding part of the glass ceramic welding seam. SiO2 powder, Al2O3 powder and Y2O3 powder are mixed, and glass solder is obtained through water quenching and ball milling; the to-be-welded areas of the cladding tube and the end plug are coated with glass solder, then the cladding tube and the end plug are assembled and placed according to a to-be-formed structure, the glass solder is filled in the position close to the inner end face of the end plug in the cladding tube, and a to-be-welded part is obtained; and a to-be-welded part is subjected to pressureless sintering under the protective atmosphere at the temperature of 1400-1550 DEG C, and the high-temperature-resistant The welding part is provided with the high-temperature-resistant connecting layer, still has a stable microstructure at the temperature of 1200 DEG C, crystal phase dissolution and impurity crystal phase precipitation are avoided, the problem of welding and packaging of the end of the SiCf / SiC composite cladding pipe is solved, and the welding part can be applied to the nuclear energy field.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic matrix composite material connection, and more specifically, relates to a SiC glass ceramic weld. f / SiC composite cladding tube-end plug weldment and its preparation method and application. Background Art

[0002] Silicon carbide (SiC) has excellent properties such as high temperature resistance, corrosion resistance, low neutron absorption cross section, low creep and low hydrogen production rate when reacting with high temperature water vapor. It has broad application prospects in the field of nuclear energy. f SiC composite materials are considered to be candidate materials for nuclear fuel cladding in the new generation of nuclear energy systems, in order to significantly improve the core's fault tolerance and power generation efficiency under accident conditions. f In the process of manufacturing nuclear fuel cladding components made of SiC composite materials, there are still many problems, such as SiC f The problem of high performance welding sealing at both ends of the / SiC composite cladding tube remains unsolved.

[0003] SiC f The material of the SiC composite cladding tube is different from the mature commercial zirconium alloy and cannot be homogenously connected by fusion welding or pressure resistance welding. It is usually necessary to introduce solder for welding. f In the field of SMD / SiC composite material connection, according to different solder types, several connection technologies have been developed, including metal brazing connection, diffusion welding, precursor connection, reaction connection, MAX phase connection, NITE phase connection and glass connection.

[0004] The advantage of glass connection technology is that the connection temperature is low, which helps to avoid SiC fiber degradation; in addition, through the design of solder composition, the thermal expansion coefficient of the solder can be controlled to be close to that of SiC, thereby significantly alleviating the thermal mismatch problem between the connection layer and the base material. However, most of the currently disclosed glass solder systems have poor high temperature resistance and cannot maintain sufficient strength to ensure the sealing of the cladding tube under LOCA accident conditions. In order to improve the high temperature resistance of glass solder, scholars have proposed to crystallize the glass solder to transform the connection layer from pure glass to glass ceramics. However, in the current public literature, the glass crystallization product and SiC are usually prone to thermal mismatch and may crack, resulting in an increase in the leakage rate of the welded parts. In addition, public literature reports that in order to convert a large amount of glass into glass ceramics, it is usually necessary to keep it warm at the crystallization temperature for a long time, which weakens the quick connection advantage of the glass connection technology and has a negative impact on the performance of the core block inside the cladding tube and the SiC f / SiC composite materials have adverse effects on the structural stability and seriously reduce the connection efficiency, which is not conducive to practical engineering and commercial applications. Summary of the invention

[0005] In order to solve the problem that the current glass connection technology cannot quickly prepare SiC with good airtightness and high temperature resistance f / SiC composite material cladding tube welding parts, the present invention provides a glass ceramic welded SiC f / SiC composite cladding tube-end plug weldment. This weldment has a high temperature resistant connection layer and still has a stable microstructure at 1200℃. It will not dissolve the crystal phase and precipitate the impurity crystal phase, solving the problem of SiC f / SiC composite cladding tube end welding packaging problem.

[0006] Another object of the present invention is that the SiC f / SiC composite cladding tube-end plug welding part preparation method. This method deposits a carbon layer on the inner surface of the cladding tube, and uses the pyrolytic carbon layer around the SiC fiber on the end face of the cladding tube as a nucleation site. The pyrolytic carbon structure can significantly promote the crystallization behavior of the current glass system, realize a large amount of crystallization during rapid welding, and obtain a glass-ceramic connection layer structure with a large amount of crystalline phases. There is no need to perform long-term heat preservation treatment on the welded parts at the crystallization temperature, which greatly improves the welding efficiency.

[0007] Another object of the present invention is to f Application of / SiC composite cladding tube-end plug weldments.

[0008] The technical solution adopted by the present invention to solve its technical problem is:

[0009] SiC for glass ceramic weld f / SiC composite cladding tube-end plug welding parts are prepared by mixing SiO2 powder, Al2O3 powder and Y2O3 powder to obtain a mixed powder, adding anhydrous ethanol and silicon nitride grinding balls, obtaining glass by water quenching and ball milling, mixing glass, anhydrous ethanol and PVB to obtain glass solder, applying the glass solder to the cladding tube and the end plug to be welded area, then assembling the cladding tube and the end plug according to the structure to be formed, and then filling the glass solder near the inner end surface of the end plug inside the cladding tube to obtain the welded parts, and then pressurelessly sintering the welded parts at 1400-1550°C under a protective atmosphere; the welded parts include a cladding tube and an end plug, and the cladding tube is composed of an inner layer of SiC f / SiC composite material and an outer SiC ceramic layer, and the end plug is SiC ceramic.

[0010] Preferably, the purity of the SiO2 powder, Al2O3 powder and Y2O3 powder is greater than 99%, and the particle size is 0.2-5 μm.

[0011] Preferably, the mass ratio of the SiO2 powder, Al2O3 powder and Y2O3 powder is (25-35):(29-35):(36-40); the mass ratio of the mixed powder, anhydrous ethanol and silicon nitride grinding balls is 1:(2-5):(2-10); the mass ratio of the glass, anhydrous ethanol and PVB is 1:(2-4):(0.002-0.02).

[0012] Preferably, the end face of the cladding tube is polished to expose the fiber layer structure, and a 50-200nm carbon layer is deposited on the inner surface of the cladding tube; the end plug has a "convex" structure, and the diameter of the large end cylinder is the same as the outer diameter of the cladding tube; the diameter of the small end cylinder is 100-600μm smaller than the inner diameter of the cladding tube, and the height of the small end cylinder is 5-10mm, and the bottom end of the end plug is a cone with a height of 0.5-2mm from the end face and a semi-cone angle of 15-75°.

[0013] Preferably, the coating method is brushing, screen printing, spraying, dipping, and the coating amount of glass solder is 60-240 mg / cm 2 The area to be welded includes the inner surface of the cladding tube, the outer surface of the small end cylinder of the end plug, and the contact surface between the end face of the cladding tube and the end plug.

[0014] Preferably, the protective atmosphere is one or more of argon, nitrogen or helium, and the pressure of the protective atmosphere is 0.01-0.1 MPa.

[0015] Preferably, the end surface connection layer thickness of the welded part is 30-300 μm, the side connection layer thickness is 50-300 μm, the joint ejection strength of the welded part is 60-90 MPa at room temperature, and the helium leakage rate is 1.0×10 -9 ~1.0×10 -12 Pa·m 3 / s; the joint ejection strength in argon atmosphere at 1000°C is 45~70MPa.

[0016] The SiC glass ceramic weld f The method for preparing a / SiC composite material cladding tube-end plug weldment comprises the following specific steps:

[0017] S1. SiO2 powder, Al2O3 powder and Y2O3 powder are mixed to obtain a mixed powder, anhydrous ethanol and silicon nitride grinding balls are added, glass is obtained by water quenching and ball milling, and glass, anhydrous ethanol and PVB are mixed to obtain glass solder;

[0018] S2. The glass solder is applied to the cladding tube and the end plug to be welded, and then the cladding tube and the end plug are assembled according to the structure to be formed, and then the glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part;

[0019] S3. Under protective atmosphere, the welded parts are pressurelessly sintered at 1400-1550℃, and after cooling, the SiC of the glass ceramic weld is obtained. f / SiC composite cladding tube-end plug welding parts; the cladding tube is composed of an inner layer of SiC f / SiC composite material and an outer SiC ceramic layer, and the end plug is SiC ceramic.

[0020] Preferably, the process parameters of the pressureless sintering in step S3 are: heating to 1400-1550°C at a rate of 50-200°C / min and keeping the temperature for 5-30min, then cooling to 800°C at a rate of 25-100°C / min and cooling with the furnace.

[0021] The SiC glass ceramic weld f Application of welded parts of / SiC composite cladding tube-end plug in the nuclear energy field.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention deposits a carbon layer on the inner surface of the cladding tube and uses the pyrolytic carbon layer around the SiC fiber on the end face of the cladding tube as a nucleation site. The pyrolytic carbon structure can significantly promote the crystallization behavior of the current glass system, achieve a large amount of crystallization during rapid welding, and obtain a glass-ceramic connecting layer structure with a large amount of crystalline phases. There is no need to perform long-term insulation treatment on the welded parts at the crystallization temperature, which greatly improves the welding efficiency.

[0024] 2. The present invention achieves fine control of the glass ceramic components of the weld by adjusting the formula ingredients and designing the rapid welding process parameters, and uses the carbon material of the cladding tube to promote crystallization, thereby obtaining a high-temperature resistant connection layer, which still has a stable microstructure at 1200°C, and does not dissolve the crystalline phase and precipitate the impurity crystalline phase. In addition, since the thermal expansion coefficients of the glass ceramic connection layer, the cladding tube and the end plug are similar, there are no initial cracks that are easily reduced in strength due to thermal mismatch. The high-temperature joint ejection strength of the welded parts in an inert atmosphere at 1000°C is 45-70MPa, which meets the end sealing strength requirements of the nuclear cladding tube.

[0025] 3. The present invention makes a chamfer at the end face of the small end diameter of the "T"-shaped end plug, so as to accommodate a part of the glass solder before welding. After the part of the solder melts at high temperature, it further penetrates into the pores of the side weld by capillary force, thereby further densifying the side weld and improving the sealing performance of the welded part. In addition, the specially designed "T"-shaped welding structure increases the end face weld, thereby further improving the sealing performance of the welded part.

[0026] 4. In the present invention, since the thermal expansion coefficients of the weld, cladding tube and end plug are similar, no cracks will occur due to thermal stress. The helium leakage rate of the welded parts reaches 1.0×10 -9 ~1.0×10 -12 Pa·m 3 / s, meeting the leakage rate index requirements for nuclear cladding tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a microstructure diagram of the glass solder in Example 1;

[0028] Figure 2 is a microstructure diagram of a transverse section of the cladding tube of the present invention;

[0029] Figure 3 (a) is a schematic diagram of the structure of the cladding tube and the end plug of the present invention, and (b) is a physical diagram of the welding part of the cladding tube and the end plug;

[0030] Figure 4 (a) Schematic diagram of the assembly structure of the cladding tube and the end plug of the present invention; (b) microstructure of the welding of the cladding tube and the end plug;

[0031] Figure 5 (a) The microstructure of the end weld after connection at 1500°C in Example 1, and (b) the microstructure of the side weld after connection at 1500°C. DETAILED DESCRIPTION

[0032] The content of the present invention is further described below in conjunction with specific examples, but it should not be construed as limiting the present invention. If not specifically indicated, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0033] The cladding tube used in the embodiment of the present invention is a tubular preform obtained by weaving SiC fibers, and then subjected to chemical vapor infiltration densification to obtain SiC f / SiC(f is the abbreviation of fiber, SiC f / SiC (i.e. SiC fiber reinforced SiC ceramic matrix) composite material layer, in SiC fThe outer surface of the / SiC composite material layer is chemically vapor deposited with silicon carbide ceramics (CVD-SiC), and finally the CVD-SiC ceramics on the outer surface are finely processed to obtain a double-layer structure cladding tube.

[0034] Example 1

[0035] 1. SiO2 (particle size 0.5 μm), Al2O3 (particle size 1 μm) and Y2O3 (particle size 1 μm) in a mass ratio of 30:31:39 were uniformly mixed, the mixed powder was placed in an alumina crucible, the temperature was raised to 1600°C at a rate of 10°C / min and the temperature was kept for 60 min for melting treatment, the molten mixture was quickly immersed in ultrapure room temperature water to obtain glass slag, the glass slag was finely ground by planetary ball milling, and dried and sieved to obtain glass;

[0036] 2. Place the cladding tube (such as Figure 2 The end face of the SiC f The fiber layer structure of the cladding tube is a carbon layer (thickness is 100nm) deposited on the inner surface of the cladding tube. The end plug is a silicon carbide ceramic with a "convex" structure. The diameter of the large end cylinder of the end plug is the same as the outer diameter of the cladding tube; the diameter of the small end cylinder of the end plug is 200μm smaller than the inner diameter of the cladding tube, the height of the small end cylinder h1=8mm, and the bottom of the end plug is a cone with a height of h2=1mm from the end face and a semi-cone angle θ=45°, such as Figure 4 As shown in (a).

[0037] 3. Mix glass, anhydrous ethanol and PVB by ultrasonic stirring to obtain glass solder, and then apply the glass solder to the welding area of ​​the cladding tube and the end plug by dipping and pulling ( Figure 4 (a) The yellow and red parts) are used to control the coating amount of glass solder powder to 100 mg / cm 2 Then, the cladding tube and the end plug are assembled according to the structure to be formed, and 2g of glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part;

[0038] 4. Place the welding part of the welded part in a heating furnace, heat it to 1500℃ at a rate of 10℃ / min under 0.05MPa argon gas, keep it warm for 15min, then cool it to 800℃ at a rate of 50℃ / min and cool it with the furnace to obtain the welded part of the cladding tube-end plug, where the inner layer of the cladding tube is SiC f / SiC composite material, the outer layer of the cladding tube is SiC coating, and the end plug is SiC ceramic, such as Figure 4 As shown in (b), the red dotted line is the welding interface.

[0039] Figure 5The microstructure of (a) the end weld after connection at 1500°C and (b) the side weld after connection at 1500°C in Example 1 are shown. Figure 5 It can be seen that the weld thickness of the end face and side face of the welded part is about 100μm. A large amount of high temperature resistant crystalline phases have been precipitated in the side and end face welds. Among them, the bright white phase is the yttrium silicate crystalline phase (Y2Si2O7), whose melting point is higher than 1700℃, and the dark second crystalline phase is alumina, whose melting point is as high as 2000℃. At room temperature, the joint ejection strength of the welded part is 90MPa (standard reference ASTM C1862-17), and the helium leakage rate is 3.0×10 -12 Pa·m 3 / s, and the high temperature joint ejection strength in argon atmosphere at 1000℃ is 65MPa.

[0040] Example 2

[0041] 1. SiO2 (particle size 1 μm), Al2O3 (particle size 5 μm) and Y2O3 (particle size 5 μm) in a mass ratio of 30:31:39 were uniformly mixed, and the mixed powder was water quenched and ball milled to obtain glass;

[0042] 2. A carbon layer (thickness of 200 nm) is deposited on the inner surface of the cladding tube. The diameter of the small end cylinder of the end plug is 600 μm smaller than the inner diameter of the cladding tube. The height of the small end cylinder is h1 = 5 mm. The bottom of the end plug is a cone with a height of h2 = 2 mm from the end surface and a semi-cone angle θ = 45°.

[0043] 3. Mix glass, anhydrous ethanol and PVB and stir them ultrasonically to obtain glass solder. Then, apply the glass solder to the welding area of ​​the cladding tube and the end plug by dipping and pulling. The coating amount of the glass solder powder is controlled to be 240 mg / cm 2 Then, the cladding tube and the end plug are assembled according to the structure to be formed, and 3g of glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part;

[0044] 4. Place the welding part of the welded part in a heating furnace, heat it to 1500℃ at a rate of 100℃ / min under 0.05MPa argon gas, and keep it warm for 15min. Then cool it to 800℃ at a rate of 50℃ / min and cool it with the furnace to obtain a cladding tube (the inner layer is SiC f / SiC composite material, the outer layer is SiC coating)-end plug (SiC ceramic) welding part.

[0045] Since the glass solder does not diffuse with the end plug and the cladding tube, the thickness of the connection layer is the same as the thickness of the weld. Among them, the thickness of the end weld depends on the connection temperature and the insulation time, and the thickness of the side weld is half of the inner diameter of the pipe minus the diameter of the small end of the end plug. The thickness of the end weld and the side weld of the welded part are both 300μm. At room temperature, the joint ejection strength of the welded part is 70MPa (standard reference ASTM C1862-17), and the helium leakage rate is 9.9×10 -10 Pa·m 3 / s, and the high temperature joint ejection strength in argon atmosphere at 1000℃ is 45MPa.

[0046] Example 3

[0047] 1. SiO2 (particle size 0.2 μm), Al2O3 (particle size 2.5 μm) and Y2O3 (particle size 5 μm) in a mass ratio of 32:30:38 were uniformly mixed, and the mixed powder was water quenched and ball milled to obtain glass;

[0048] 2. A carbon layer (thickness of 50 nm) is deposited on the inner surface of the cladding tube. The diameter of the small end cylinder of the end plug is 400 μm smaller than the inner diameter of the cladding tube. The height of the small end cylinder is h1 = 10 mm. The bottom of the end plug is a cone with a height of h2 = 0.5 mm from the end surface and a semi-cone angle θ = 45°.

[0049] 3. Mix glass, anhydrous ethanol and PVB and stir them ultrasonically to obtain glass solder. Then, apply the glass solder to the welding area of ​​the cladding tube and the end plug by dipping and pulling. The coating amount of the glass solder powder is controlled to be 150mg / cm 2 Then, the cladding tube and the end plug are assembled and placed according to the structure to be formed, and 1.5 g of glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part;

[0050] 4. Place the welding part of the welded part in a heating furnace, heat it to 1550℃ at a rate of 200℃ / min under 0.01MPa argon gas, weld it and keep it warm for 15min, then cool it to 800℃ at a rate of 50℃ / min and cool it with the furnace to obtain the cladding tube (the inner layer is SiC f / SiC composite material, the outer layer is SiC coating)-end plug (SiC ceramic) welding part.

[0051] The end weld thickness of the welded part is about 150 μm, and the side weld thickness is about 200 μm. The joint ejection strength of the welded part at room temperature is 85 MPa, and the helium leakage rate is 5.0×10 -11 Pa·m 3 / s, and the high temperature joint ejection strength in argon atmosphere at 1000℃ is 60MPa.

[0052] Example 4

[0053] 1. SiO2 (particle size 0.5 μm), Al2O3 (2.5 μm) and Y2O3 (2.5 μm) in a mass ratio of 25:35:40 were uniformly mixed, water quenched and ball milled to obtain glass.

[0054] 2. A carbon layer (thickness of 150 nm) is deposited on the inner surface of the cladding tube. The diameter of the small end cylinder of the end plug is 200 μm smaller than the inner diameter of the cladding tube. The height of the small end cylinder h1 = 10 mm. The bottom of the end plug is a cone with a height of h2 = 1 mm from the end surface and a semi-cone angle θ = 45°.

[0055] 3. Mix glass, anhydrous ethanol and PVB and stir them ultrasonically to obtain glass solder. Then, apply the glass solder to the welding area of ​​the cladding tube and the end plug by dipping and pulling. The coating amount of the glass solder powder is controlled to be 100 mg / cm 2 Then, the cladding tube and the end plug are assembled according to the structure to be formed, and 1g of glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part;

[0056] 4. Place the welded part of the welded part in a heating furnace, heat it to 1450℃ at a rate of 100℃ / min under 0.1MPa argon gas, weld it and keep it warm for 15min, then cool it to 800℃ at a rate of 50℃ / min and cool it with the furnace to obtain a cladding tube (the inner layer is SiC f / SiC composite material, the outer layer is SiC coating)-end plug (SiC ceramic) welding part.

[0057] The end weld thickness of the welded part is about 150 μm, and the side weld thickness is about 100 μm. The joint ejection strength of the welded part at room temperature is 80 MPa, and the helium leakage rate is 7.5×10 -10 Pa·m 3 / s, and the high temperature joint ejection strength in argon atmosphere at 1000℃ is 65MPa.

[0058] Example 5

[0059] 1. SiO2 (particle size 5 μm), Al2O3 (particle size 5 μm) and Y2O3 (particle size 5 μm) in a mass ratio of 35:29:36 were uniformly mixed, and the mixed powder was water quenched and ball milled to obtain glass;

[0060] 2. A carbon layer (thickness of 100 nm) is deposited on the inner surface of the cladding tube. The diameter of the small end cylinder of the end plug is 100 μm smaller than the inner diameter of the cladding tube. The height of the small end cylinder is h1 = 9 mm. The bottom of the end plug is a cone with a height of h2 = 1 mm from the end surface and a semi-cone angle θ = 45°.

[0061] 3. Mix glass, anhydrous ethanol and PVB and stir them ultrasonically to obtain glass solder. Then, apply the glass solder to the welding area of ​​the cladding tube and the end plug by dipping and pulling. The coating amount of the glass solder powder is controlled to be 150mg / cm 2 Then, the cladding tube and the end plug are assembled and placed according to the structure to be formed, and 1g of glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part;

[0062] 4. Place the welding part of the welded part in a heating furnace, heat it to 1550℃ at a rate of 500℃ / min under 0.02MPa argon gas, and keep it warm for 15min, then cool it to 800℃ at a rate of 50℃ / min and cool it with the furnace to obtain a cladding tube (the inner layer is SiC f / SiC composite material, the outer layer is SiC coating)-end plug (SiC ceramic) welding part.

[0063] The end weld thickness of the welded part is about 40 μm, and the side weld thickness is about 50 μm. The joint ejection strength of the welded part at room temperature is 90 MPa, and the helium leakage rate is 9.9×10 -11 Pa·m 3 / s, and the high temperature joint ejection strength in argon atmosphere at 1000℃ is 45MPa.

[0064] The end surface connection layer thickness of the cladding tube-end plug weldment of the present invention is 30-300 μm, the side connection layer thickness is 50-300 μm, the joint ejection strength of the weldment at room temperature is 60-90 MPa, and the helium leakage rate is 1.0×10 -9 ~1.0×10 - 12 Pa·m 3 / s, the high temperature joint ejection strength in argon atmosphere at 1000℃ is 45~70MPa. The welded part has a high temperature resistant connection layer and still has a stable microstructure at 1200℃. Crystal phase dissolution and impurity crystal phase precipitation will not occur, which solves the problem of SiC f / SiC composite cladding tube end welding packaging problem, can be applied in the nuclear energy field.

[0065] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A SiC glass ceramic weld f / SiC composite cladding tube-end plug weldment, characterized in that: The welding part is prepared by mixing SiO2 powder, Al2O3 powder and Y2O3 powder to obtain a mixed powder, adding anhydrous ethanol and silicon nitride grinding balls, and obtaining glass by water quenching and ball milling. The glass, anhydrous ethanol and PVB are mixed to obtain glass solder, and the glass solder is applied to the welding area of ​​the cladding tube and the end plug. The cladding tube and the end plug are then assembled according to the structure to be formed, and the glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welding part, and the welding part is obtained by pressureless sintering at 1400-1550° C. under a protective atmosphere. The welding part includes a cladding tube and an end plug, and the cladding tube is composed of an inner layer of SiC f / SiC composite material and an outer SiC ceramic layer, and the end plug is SiC ceramic.

2. SiC of the glass ceramic weld according to claim 1 f / SiC composite cladding tube-end plug weldment, characterized in that: The purity of the SiO2 powder, Al2O3 powder and Y2O3 powder is greater than 99%, and the particle size is 0.2-5 μm.

3. SiC of the glass ceramic weld according to claim 1 f / SiC composite cladding tube-end plug weldment, characterized in that: The mass ratio of the SiO2 powder, Al2O3 powder and Y2O3 powder is (25-35):(29-35):(36-40); the mass ratio of the mixed powder, anhydrous ethanol and silicon nitride grinding balls is 1:(2-5):(2-10); the mass ratio of the glass, anhydrous ethanol and PVB is 1:(2-4):(0.002-0.02).

4. The SiC of the glass ceramic weld according to claim 1 f / SiC composite cladding tube-end plug weldment, characterized in that: The end face of the cladding tube is polished to expose the fiber layer structure, and a 50-200nm carbon layer is deposited on the inner surface of the cladding tube; the end plug is in a "convex" shape, the diameter of the large end cylinder is the same as the outer diameter of the cladding tube; the diameter of the small end cylinder is 100-600μm smaller than the inner diameter of the cladding tube, the height of the small end cylinder is 5-10mm, and the bottom end of the end plug is a cone with a height of 0.5-2mm from the end face and a semi-cone angle of 15-75°.

5. The SiC of the glass ceramic weld according to claim 1 f / SiC composite cladding tube-end plug weldment, characterized in that: The coating method is brushing, screen printing, spraying or dipping; the coating amount of glass solder is 60-240 mg / cm 2 .

6. The SiC of the glass ceramic weld according to claim 1 f / SiC composite cladding tube-end plug weldment, characterized in that: The protective atmosphere is one or more of argon, nitrogen or helium, and the pressure of the protective atmosphere is 0.01-0.1 MPa.

7. The SiC of the glass ceramic weld according to claim 1 f / SiC composite cladding tube-end plug weldment, characterized in that: The end surface connection layer thickness of the welded part is 30-300 μm, the side connection layer thickness is 50-300 μm, the joint ejection strength of the welded part is 60-90 MPa at room temperature, and the helium leakage rate is 1.0×10 -9 ~1.0×10 -12 Pa·m 3 / s; the joint ejection strength in argon atmosphere at 1000°C is 45~70MPa.

8. The SiC of the glass ceramic weld according to any one of claims 1 to 7 f A method for preparing a / SiC composite material cladding tube-end plug weldment, characterized in that: The specific steps include: S1. SiO2 powder, Al2O3 powder and Y2O3 powder are mixed to obtain a mixed powder, anhydrous ethanol and silicon nitride grinding balls are added, glass is obtained by water quenching and ball milling, and glass, anhydrous ethanol and PVB are mixed to obtain glass solder; S2. The glass solder is applied to the cladding tube and the end plug to be welded, and then the cladding tube and the end plug are assembled according to the structure to be formed, and then the glass solder is filled near the inner end surface of the end plug inside the cladding tube to obtain the welded part; S3. Under protective atmosphere, the welded parts are pressurelessly sintered at 1400-1550℃, and after cooling, the SiC of the glass ceramic weld is obtained. f / SiC composite cladding tube-end plug welding parts; the cladding tube is composed of an inner layer of SiC f / SiC composite material and an outer SiC ceramic layer, and the end plug is SiC ceramic.

9. The SiC of the glass ceramic weld according to claim 8 f A method for preparing a / SiC composite material cladding tube-end plug weldment, characterized in that: The process parameters of the pressureless sintering in step S3 are: heating to 1400-1550°C at a rate of 50-200°C / min and keeping the temperature for 5-30min, then cooling to 800°C at a rate of 25-100°C / min and cooling with the furnace.

10. The SiC of the glass ceramic weld according to any one of claims 1 to 7 f Application of / SiC composite cladding tube-end plug weldments in the nuclear energy field.

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