Riveting connection manufacturing method of silicon carbide cladding and end plug and connection structure of silicon carbide cladding and end plug

Abstract

The invention belongs to the technical field of nuclear power, and particularly relates to a riveting connection manufacturing method of a silicon carbide cladding and an end plug and a connection structure of the silicon carbide cladding and the end plug. According to the riveting connection manufacturing method for the silicon carbide cladding and the end plug, a riveting connection structure (as shown in Figure 1 and Figure 2) is designed and adopted for solving the existing problems of connection of a silicon carbide cladding tube and the end plug, including insufficient connection strength, low air tightness, limited use temperature, mismatched thermal expansion coefficients and the like; and silicon carbide is deposited through the CVI process to fill the connecting positions and the riveting holes to achieve connection. The connecting structure and method have the advantages that the double-pin design is adopted, the connecting strength can be effectively improved, silicon carbide is deposited and filled at the connecting positions and the riveting holes through the CVI technology to achieve sealing, the filled silicon carbide and the silicon carbide of the cladding base body are the same in material structure, the problem that the thermal expansion coefficients are not matched does not exist, and the using temperature is high.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power, and in particular relates to a riveting connection manufacturing method for a silicon carbide cladding and an end plug and a connection structure thereof. Background Art

[0002] Silicon carbide cladding tubes are expected to become a new generation of nuclear power accident-resistant fuel cladding, and the connection between silicon carbide cladding tubes and end plugs is an important key technology.

[0003] In terms of the connection between the silicon carbide cladding tube and the end plug, the existing connection technologies under development include metal welding, solid phase diffusion, MAX phase, precursor polymer cracking, NITE connection, glass ceramic connection, etc. Various connection methods are in the research and development stage. Generally speaking, there are still problems such as insufficient connection strength, low air tightness, limited operating temperature, and mismatched thermal expansion coefficient. Summary of the invention

[0004] In order to overcome the problems existing in the related art, a riveting connection manufacturing method and a connection structure of a silicon carbide cladding and an end plug are provided.

[0005] According to one aspect of an embodiment of the present disclosure, a method for riveting a silicon carbide cladding and an end plug is provided, the method comprising:

[0006] Step 1: riveting structural parts and processing and manufacturing;

[0007] Step 1.1, using a silicon carbide cladding prepared by a CVI process and a silicon carbide blank prepared by sintering β-silicon carbide powder, firstly processing the silicon carbide blank into the shape of a silicon carbide end plug according to the inner diameter of the cladding;

[0008] Step 1.2, processing the inner surface of the silicon carbide cladding and the outer surface of the end plug so that a clearance fit is formed between the end plug and the cladding;

[0009] Step 1.3, the outer diameter and length of the pin are processed to be consistent with the outer diameter of the silicon carbide cladding, and then pin holes are processed at the end of the silicon carbide cladding and the end plug respectively, so that a clearance fit is formed between the pin and the pin hole;

[0010] Step 2, assembling riveted structural parts;

[0011] Step 2.1, assemble the components described in step 1 according to the riveting structure, first put the lower end plug into the silicon carbide cladding, and then install the pins in sequence;

[0012] Step 2.2, after the lower end plug is connected, install the simulated core block and the compression pad, and put in the upper end plug and the pin;

[0013] Step 3, deposition and plugging;

[0014] Step 3.1, the silicon carbide cladding with the end plugs and pins assembled is vertically hung in a vapor deposition furnace;

[0015] Step 3.2, start the vapor deposition furnace, introduce argon, hydrogen, and trichloromethylsilane gas, and deposit at 1050° C. for 50-100 hours.

[0016] In a possible implementation, in step 1.1, the inner diameter of the silicon carbide cladding is 7.5-10 mm; in step 1.2, the inner surface of the silicon carbide cladding and the outer surface of the end plug are processed to form a clearance fit of 40-80 μm between the end plug and the cladding.

[0017] In one possible implementation, in step 1.3, the pin is processed to have an outer diameter of 5-7 mm, and the pin length is consistent with the outer diameter of the cladding. Then, pin holes are processed at the ends of the silicon carbide cladding and the end plug at a distance of 10 mm and 22 mm from the top of the end plug, respectively, to form a clearance fit of 40-80 μm between the pin and the pin hole.

[0018] According to one aspect of an embodiment of the present disclosure, a riveted connection structure of a silicon carbide cladding and an end plug is provided. In the riveted connection structure of the silicon carbide cladding and the end plug formed by the manufacturing method as described above, the cladding is tubular, and an end plug is respectively inserted into the ports at both ends of the cladding, and opposite pin holes are provided on the cladding and the end plug, and a pin is inserted into every two opposite pin holes, so that the cladding and the end plug are riveted; the gaps between the ports at both ends of the cladding and the end plug, and the gaps between the pins and the pin holes are sealed by the CVI process.

[0019] In a possible implementation, the inner diameter of the cladding is 7.5-10 mm; and a clearance fit of 40-80 μm is formed between the end plug and the cladding.

[0020] In a possible implementation, the outer diameter of the pin is 5-7 mm, and a clearance fit of 40-80 μm is formed between the pin and the pin hole.

[0021] In a possible implementation, pin holes are processed on the cladding at 10 mm and 22 mm away from the top end of the end plug.

[0022] The beneficial effects of the present disclosure are as follows: the present disclosure provides a method for riveting a silicon carbide cladding tube and an end plug, which aims to solve the existing problems of connecting a silicon carbide cladding tube and an end plug, including insufficient connection strength, low air tightness, limited use temperature, mismatched thermal expansion coefficient, etc., and designs a riveting connection structure (such as Figure 1 , Figure 2As shown in the figure, the connection is achieved by filling the joints and rivet holes with silicon carbide deposited by the CVI process. The advantages of this connection structure and method are: the double pin design can effectively increase the connection strength, the CVI process is used to deposit and fill silicon carbide at the joints and rivet holes to achieve sealing, the filled silicon carbide has the same material structure as the silicon carbide of the cladding matrix, there is no problem of mismatch in thermal expansion coefficient, and the operating temperature is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart showing a method for making a riveted connection between a silicon carbide cladding and an end plug according to an exemplary embodiment.

[0024] Figure 2 The figure is an exploded view of a riveted connection structure between a silicon carbide cladding and an end plug according to an exemplary embodiment.

[0025] Figure 3 It is an assembly diagram of a riveted connection structure of a silicon carbide cladding and an end plug according to an exemplary embodiment. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Figure 1 FIG. 1 is a flow chart showing a method for making a riveted connection between a silicon carbide cladding and an end plug according to an exemplary embodiment. Figure 1 As shown, the method includes the following steps.

[0028] Step 1: Riveting structural parts and processing and manufacturing.

[0029] Step 1.1, a silicon carbide cladding prepared by CVI process and a silicon carbide blank prepared by sintering β-silicon carbide powder, wherein the inner diameter of the silicon carbide cladding is 7.5-10 mm, and the silicon carbide blank is first processed into the shape of a silicon carbide end plug according to the inner diameter of the cladding.

[0030] Step 1.2, processing the inner surface of the silicon carbide cladding and the outer surface of the end plug so that a clearance fit of 40-80 μm is formed between the end plug and the cladding.

[0031] Step 1.3, process the pin with an outer diameter of 5-7mm and a length consistent with the outer diameter of the silicon carbide cladding, and then process pin holes at the end of the silicon carbide cladding and the end plug at a distance of 10mm and 22mm from the top of the end plug respectively, forming a clearance of 40-80μm between the pin and the pin hole.

[0032] Step 2: Assemble the riveted structural parts.

[0033] Step 2.1, assemble the components described in step 1 according to the riveting structure, first put the lower end plug into the silicon carbide cladding, and then install the pins in sequence.

[0034] Step 2.2, after the lower end plug is connected, install the simulated core block and the compression pad, and put in the upper end plug and the pin.

[0035] Step 3: Sedimentation and sealing.

[0036] Step 3.1, the silicon carbide cladding with the end plugs and pins assembled is vertically hung in the vapor deposition furnace.

[0037] Step 3.2, start the vapor deposition furnace, introduce argon, hydrogen, and trichloromethylsilane gas, and deposit at 1050° C. for 50-100 hours.

[0038] The method disclosed in the present invention realizes the connection between the silicon carbide cladding and the end plug by adopting the riveted connection structure of the silicon carbide cladding and the end plug and the CVI process method. This connection method has the characteristics of high connection strength and high airtightness. Since the CVI process is used to deposit silicon carbide to fill the connection, the use temperature and thermal expansion coefficient after connection are consistent with those of the silicon carbide cladding.

[0039] Figure 2 is an exploded view of a riveted connection structure of a silicon carbide cladding and an end plug according to an exemplary embodiment. Figure 3 is an assembly diagram of a riveted connection structure of a silicon carbide cladding and an end plug according to an exemplary embodiment, such as Figure 2 and Figure 3 As shown, in the riveted connection structure of the silicon carbide cladding and the end plug formed by the above-mentioned manufacturing method, the cladding 3 is tubular, and an end plug 2 is respectively inserted into the ports at both ends of the cladding, and opposite pin holes 1 are provided on the cladding and the end plug, and a pin 4 is inserted into every two opposite pin holes 1, so that the cladding 3 and the end plug 2 are riveted; the gaps between the ports at both ends of the cladding 3 and the end plug 2, and the gaps between the pins 4 and the pin holes 1 are sealed by the CVI process.

[0040] In an application example, the method includes the following steps.

[0041] Step 1: Riveting structural parts and processing

[0042] Step 1.1: The silicon carbide cladding prepared by the CVI process and the silicon carbide blank prepared by sintering β-silicon carbide powder, the inner diameter of the silicon carbide cladding is 7.5. According to the inner diameter of the cladding, the silicon carbide blank is first processed into the shape of a silicon carbide end plug.

[0043] Step 1.2: The inner surface of the silicon carbide cladding and the outer surface of the end plug are finely processed to form a clearance fit of 40-80 μm between the end plug and the cladding.

[0044] Step 1.3: The pin is processed to have an outer diameter of 6mm and a length consistent with the outer diameter of the silicon carbide cladding. Then, pin holes are processed at the ends of the silicon carbide cladding and the end plug, 10mm and 22mm away from the top of the end plug, respectively, to form a clearance of 60μm between the pin and the pin hole.

[0045] Step 2: Riveting structural parts assembly

[0046] Step 2.1: Assemble the components described in step 1 according to the riveting structure, first place the lower end plug into the silicon carbide cladding, and then install the pins in sequence.

[0047] Step 2.2: After the lower end plug is connected, install the simulated core block and the compression pad, and put in the upper end plug and the pin.

[0048] Step 3: Sedimentation and sealing

[0049] Step 3.1: The silicon carbide cladding with end plugs and pins assembled is vertically hung in the vapor deposition furnace.

[0050] Step 3.2: Start the vapor deposition furnace, introduce argon, hydrogen and trichloromethylsilane gases, and deposit at 1050° C. for 80 h.

[0051] In another application example, the method includes the following steps.

[0052] Step 1: Riveting structural parts and processing

[0053] Step 1.1: The silicon carbide cladding prepared by the CVI process and the silicon carbide blank prepared by sintering β-silicon carbide powder, the inner diameter of the silicon carbide cladding is 10, and according to the inner diameter of the cladding, the silicon carbide blank is first processed into the shape of a silicon carbide end plug.

[0054] Step 1.2: The inner surface of the silicon carbide cladding and the outer surface of the end plug are finely processed to form a clearance fit of 70 μm between the end plug and the cladding.

[0055] Step 1.3: The pin is processed to have an outer diameter of 6mm and a length consistent with the outer diameter of the silicon carbide cladding. Then, pin holes are processed at the ends of the silicon carbide cladding and the end plug, 10mm and 22mm away from the top of the end plug, respectively, to form a clearance of 70μm between the pin and the pin hole.

[0056] Step 2: Riveting structural parts assembly

[0057] Step 2.1: Assemble the components described in step 1 according to the riveting structure, first place the lower end plug into the silicon carbide cladding, and then install the pins in sequence.

[0058] Step 2.2: After the lower end plug is connected, install the simulated core block and the compression pad, and put in the upper end plug and the pin.

[0059] Step 3: Sedimentation and sealing

[0060] Step 3.1: The silicon carbide cladding with end plugs and pins assembled is vertically hung in the vapor deposition furnace.

[0061] Step 3.2: Start the vapor deposition furnace, introduce argon, hydrogen and trichloromethylsilane gases, and deposit at 1050° C. for 100 h.

[0062] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for riveting a silicon carbide cladding and an end plug, characterized in that: The method comprises: Step 1: riveting structural parts and processing and manufacturing; Step 1.1, using a silicon carbide cladding prepared by a CVI process and a silicon carbide blank prepared by sintering β-silicon carbide powder, firstly processing the silicon carbide blank into the shape of a silicon carbide end plug according to the inner diameter of the cladding; Step 1.2, processing the inner surface of the silicon carbide cladding and the outer surface of the end plug so that a clearance fit is formed between the end plug and the cladding; Step 1.3, the outer diameter and length of the pin are processed to be consistent with the outer diameter of the silicon carbide cladding, and then pin holes are processed at the end of the silicon carbide cladding and the end plug respectively, so that a clearance fit is formed between the pin and the pin hole; Step 2, assembling riveted structural parts; Step 2.1, assemble the components described in step 1 according to the riveting structure, first put the lower end plug into the silicon carbide cladding, and then install the pins in sequence; Step 2.2, after the lower end plug is connected, install the simulated core block and the compression pad, and put in the upper end plug and the pin; Step 3, deposition and plugging; Step 3.1, the silicon carbide cladding with the end plugs and pins assembled is vertically hung in a vapor deposition furnace; Step 3.2, start the vapor deposition furnace, introduce argon, hydrogen, and trichloromethylsilane gas, and deposit at 1050° C. for 50-100 hours.

2. The method according to claim 1, characterized in that In step 1.1, the inner diameter of the silicon carbide cladding is 7.5-10 mm; in step 1.2, the inner surface of the silicon carbide cladding and the outer surface of the end plug are processed so that a clearance fit of 40-80 μm is formed between the end plug and the cladding.

3. The method according to claim 1, characterized in that In step 1.3, the pin is processed to an outer diameter of 5-7 mm, and the pin length is consistent with the outer diameter of the cladding. Then, pin holes are processed at the end of the silicon carbide cladding and the end plug at a distance of 10 mm and 22 mm from the top of the end plug, respectively, to form a clearance of 40-80 μm between the pin and the pin hole.

4. A riveted connection structure of a silicon carbide cladding and an end plug, characterized in that: In the riveted connection structure of the silicon carbide cladding and the end plug formed by the manufacturing method as described in any one of claims 1 to 3, the cladding is tubular, and an end plug is inserted into the ports at both ends of the cladding respectively, and opposite pin holes are provided on the cladding and the end plug, and a pin is inserted into every two opposite pin holes, so that the cladding and the end plug are riveted; the gaps between the ports at both ends of the cladding and the end plugs, and the gaps between the pins and the pin holes are sealed by the CVI process.

5. The method according to claim 1, characterized in that The inner diameter of the cladding is 7.5-10 mm; a clearance fit of 40-80 μm is formed between the end plug and the cladding.

6. The method according to claim 1, characterized in that The outer diameter of the pin is 5-7 mm, and a clearance fit of 40-80 μm is formed between the pin and the pin hole.

7. The method according to claim 1, characterized in that Pin holes are machined on the cladding at 10mm and 22mm from the top of the end plug.

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