阅读说明：本技术 一种碳化硅复合材料燃料包壳与端塞的连接方法 (Method for connecting silicon carbide composite fuel cladding and end plug ) 是由 卢永恒 冯海宁 郭洪 王虹 康泰峰 刘建成 单宏祎 孟莹 田广丰 黄立功 于 2020-12-31 设计创作，主要内容包括：本发明属于新型核包壳材料制造技术领域,具体涉及一种碳化硅复合材料燃料包壳与端塞的连接方法。采用SiO-2、Al-2O-3和Y-2O-3共3种氧化物为原料,根据配比称取原料,将其进行混合球磨,通过挤压成型的方法制备成小圆柱体。将这些圆柱放入坩埚中在高温下进行热处理,为了实现熔体成分的均匀,样品在高温下保温一段时间,然后将熔融的样品放入水中淬火以得到玻璃体,将所制备的玻璃块经球磨后过150目筛得到所需要得钎料。本发明解决SiC复合材料包壳管的两端密封问题,进而为该包壳管的应用提供条件。(The invention belongs to the technical field of novel nuclear cladding material manufacturing, and particularly relates to a method for connecting a silicon carbide composite material fuel cladding and an end plug. By means of SiO 2 、Al 2 O 3 And Y 2 O 3 3 kinds of oxides are taken as raw materials, the raw materials are weighed according to the proportion, mixed and ball-milled, and the mixture is prepared into a small cylinder by an extrusion forming method. And (3) putting the cylinders into a crucible for heat treatment at high temperature, keeping the temperature of a sample at high temperature for a period of time in order to realize the uniformity of melt components, then putting the molten sample into water for quenching to obtain a vitreous body, and ball-milling the prepared glass block and then sieving the glass block with a 150-mesh sieve to obtain the required brazing filler metal. The invention solves the problem of sealing the two ends of the SiC composite material cladding tube, thereby providing conditions for the application of the cladding tube.)

1. A method of connecting a silicon carbide composite fuel cladding to an end plug, characterized by:

the method comprises the following steps: mixing SiO₂、Al₂O₃And Y₂O₃Weighing and proportioning 3 oxides;

step two: mixing the mixed SiO₂、Al₂O₃And Y₂O₃Putting the raw materials into a ball milling tank, and carrying out ball milling on a planetary ball mill;

step three: putting the ball-milled raw materials into a stainless steel mold, pressing and molding on a press, and pressing into a cylinder;

step four: putting the pressed cylinder into a graphite crucible, putting the graphite crucible into a high-temperature furnace, heating for reaction, taking out the graphite crucible after heat preservation, and quickly putting the graphite crucible into water to obtain a vitreous body;

step five: putting the prepared glass body into a stainless steel ball milling tank, and carrying out ball milling on a planetary ball mill to prepare powder;

step six: screening the ball-milled powder, and taking the screened fine powder to obtain the required brazing filler metal;

step seven: cleaning and drying the cladding tube and the end plug to be connected, and fully mixing the prepared brazing filler metal with absolute ethyl alcohol;

step eight: uniformly brushing the brazing filler metal mixed with the ethanol on the inner surface of the cladding tube to be connected and the outer surface of the end plug, and embedding and combining the cladding tube and the end plug;

step nine: and (4) placing the combined cladding tube and end plug into a graphite crucible, placing into a high-temperature furnace, heating, preserving heat and completing connection.

2. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: the method comprises the following steps: in weight ratio of SiO₂ 40-50％wt.％，Al₂O₃20-30％wt.％，Y₂O₃25-35％wt.％。

3. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step two: the ball milling revolution is 300r/min, and the ball milling lasts for 2 hours.

4. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step three: pressing and molding on a 60T press, pressing into a cylinder with the diameter of 30mm, keeping the pressure at 20T for 10 s.

5. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step four: putting the mixture into a high-temperature furnace, heating to 1400-1700 ℃ for reaction, keeping the temperature for 2 hours, taking out the mixture and quickly putting the mixture into water to obtain a vitreous body.

6. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step five: the ball milling revolution is 300r/min, and the ball milling lasts for 1-3 h.

7. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step six: and screening the ball-milled powder on a 150-mesh sieve.

8. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step seven: and fully mixing the prepared brazing filler metal with absolute ethyl alcohol according to the mass ratio of 1: 3.

9. The method of connecting a silicon carbide composite fuel cladding to an end plug according to claim 1, wherein: step nine: heating to 1300 ℃ and 1600 ℃, and preserving the heat for 0.5-2h to finish the connection.

Technical Field

The invention belongs to the technical field of novel nuclear cladding material manufacturing, and particularly relates to a method for connecting a silicon carbide composite material fuel cladding and an end plug.

Background

SiC is regarded as a main candidate material of the nuclear fuel cladding for the current light water reactor, and is expected to be applied to accident fault-tolerant fuel elements. SiC has many advantages such as a small neutron absorption cross section, good chemical stability, ability to withstand high fuel burn-up and temperature, non-sustained irradiation growth, and low induced activation and decay heat, and can remain stable in nuclear waste for long periods of time, providing better safety for water-cooled reactors under lost cooling (LOCA) and other potential accident conditions. In recent years, particularly after the fukushima nuclear accident, a great deal of research work is carried out at home and abroad aiming at the SiC ceramic composite material cladding, traditional nuclear power strengthening countries such as America, Japan, France and the like are all carried out in the field, the research of the subject is carried out by domestic Zhongke group, Zhongguan group, China power supply, West industry and other units, the scale of the cladding tube is adopted at present, the stage progress in the aspects of process preparation and performance is achieved, the connection of the SiC ceramic composite material cladding and an end plug is also one of key technologies, and the process exploration stage is still existed at present.

Existing silicon carbide composite joining techniques are generally relatively crude and generally involve several modes of brazing, diffusion, and extrusion.

Brazing is a common connection mode, i.e., brazing filler metal is used to connect different materials, but adding brazing filler metal easily causes uneven welding spot areas and damages. Meanwhile, the brazing temperature is low, the pipe connection area can be broken at high temperature, and the safety of the pipe cannot be guaranteed.

And the diffusion adopts metal as an interlayer, the metal is uniformly permeated, and the metal is connected with the base metal after solidification. But requires dimensional machining of the silicon carbide composite material, which may result in structural damage to the material.

Good ductility is required for press deformation, but the silicon carbide material has poor ductility, and thus the pressing method cannot be used.

Disclosure of Invention

The invention aims to provide a method for connecting a silicon carbide composite fuel cladding and an end plug, which solves the problem of sealing two ends of a SiC composite material cladding tube and further provides conditions for application of the cladding tube.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for connecting a silicon carbide composite fuel cladding and an end plug,

the method comprises the following steps: mixing SiO₂、Al₂O₃And Y₂O₃Weighing and proportioning 3 oxides;

step two: mixing the mixed SiO₂、Al₂O₃And Y₂O₃Putting the raw materials into a ball milling tank, and carrying out ball milling on a planetary ball mill;

step three: putting the ball-milled raw materials into a stainless steel mold, pressing and molding on a press, and pressing into a cylinder;

step four: putting the pressed cylinder into a graphite crucible, putting the graphite crucible into a high-temperature furnace, heating for reaction, taking out the graphite crucible after heat preservation, and quickly putting the graphite crucible into water to obtain a vitreous body;

step five: putting the prepared glass body into a stainless steel ball milling tank, and carrying out ball milling on a planetary ball mill to prepare powder;

step six: screening the ball-milled powder, and taking the screened fine powder to obtain the required brazing filler metal;

step seven: cleaning and drying the cladding tube and the end plug to be connected, and fully mixing the prepared brazing filler metal with absolute ethyl alcohol;

step eight: uniformly brushing the brazing filler metal mixed with the ethanol on the inner surface of the cladding tube to be connected and the outer surface of the end plug, and embedding and combining the cladding tube and the end plug;

step nine: and (4) placing the combined cladding tube and end plug into a graphite crucible, placing into a high-temperature furnace, heating, preserving heat and completing connection.

The method comprises the following steps: in weight ratio of SiO₂ 40-50％wt.％，Al₂O₃ 20-30％wt.％，Y₂O₃ 25-35％wt.％。

Step two: the ball milling revolution is 300r/min, and the ball milling lasts for 2 hours.

Step three: pressing and molding on a 60T press, pressing into a cylinder with the diameter of 30mm, keeping the pressure at 20T for 10 s.

Step four: putting the mixture into a high-temperature furnace, heating to 1400-1700 ℃ for reaction, keeping the temperature for 2 hours, taking out the mixture and quickly putting the mixture into water to obtain a vitreous body.

Step five: the ball milling revolution is 300r/min, and the ball milling lasts for 1-3 h.

Step six: and screening the ball-milled powder on a 150-mesh sieve.

Step seven: and fully mixing the prepared brazing filler metal with absolute ethyl alcohol according to the mass ratio of 1: 3.

Step nine: heating to 1300 ℃ and 1600 ℃, and preserving the heat for 0.5-2h to finish the connection.

The beneficial effects obtained by the invention are as follows:

the invention provides a method for connecting a silicon carbide cladding and an end plug, which is used for connecting the silicon carbide cladding and the end plug, and the air tightness reaches 3.6 multiplied by 10 after testing^-9Pa·m³And/s, the design requirement is met, the problem of sealing the two ends of the SiC composite material cladding tube is solved, and conditions are provided for the application of the cladding tube.

Detailed Description

The present invention will be described in detail with reference to specific examples.

By means of SiO₂、Al₂O₃And Y₂O₃3 kinds of oxides are taken as raw materials, the raw materials are weighed according to the proportion, mixed and ball-milled, and the mixture is prepared into a small cylinder by an extrusion forming method. Placing the cylinders into a crucible, performing heat treatment at high temperature, keeping the temperature of the sample at high temperature for a period of time in order to realize the uniformity of melt components, then putting the molten sample into water for quenching to obtain a glass body, ball-milling the prepared glass block, and sieving with 150-mesh sieveAnd screening to obtain the required brazing filler metal.

Cleaning and drying the cladding tube and the end plug to be connected, fully mixing the prepared brazing filler metal and absolute ethyl alcohol according to the mass ratio of 1:3, uniformly coating the brazing filler metal on the surface of a sample to be connected, embedding and combining the cladding tube and the end plug coated with the brazing filler metal, placing the cladding tube and the end plug in a graphite mold, and finally performing heat treatment at high temperature to complete connection.

The technical scheme for realizing the purpose of the invention is as follows: a method for connecting a SiC composite material cladding tube and an end plug comprises the following steps:

the method comprises the following steps: mixing SiO₂、Al₂O₃And Y₂O₃Weighing and proportioning 3 oxides in a weight ratio of SiO₂ 40-50％wt.％，Al₂O₃20-30％wt.％，Y₂O₃ 25-35％wt.％；

Step two: mixing the mixed SiO₂、Al₂O₃And Y₂O₃3 raw materials are put into a ball milling tank, and are ball milled on a planetary ball mill with the ball milling revolution number of 300r/min for 2 hours;

step three: putting the ball-milled raw materials into a stainless steel mold, performing pressure molding on the stainless steel mold on a 60T press, pressing the mixture into a cylinder with the phi of 30mm, keeping the pressure at 20T for 10 s;

step four: putting the pressed cylinder into a graphite crucible, putting the graphite crucible into a high-temperature furnace, heating to 1400 ℃ and 1700 ℃ (depending on components) for reaction, keeping the temperature for 2h, taking out the cylinder, and quickly putting the cylinder into water to obtain a vitreous body;

step five: putting the prepared glass body into a stainless steel ball milling tank, and carrying out ball milling on a planetary ball mill to prepare powder, wherein the ball milling revolution is 300r/min, and the ball milling lasts for 1-3 h;

step six: screening the ball-milled powder on a 150-mesh sieve, and taking the screened fine powder to obtain the required brazing filler metal;

step seven: cleaning and drying a cladding tube and an end plug to be connected, and fully mixing the prepared brazing filler metal and absolute ethyl alcohol according to the mass ratio of 1: 3;

step eight: uniformly brushing the brazing filler metal mixed with the ethanol on the inner surface of the cladding tube to be connected and the outer surface of the end plug, and embedding and combining the cladding tube and the end plug;

step nine: and (3) placing the combined cladding tube and end plug into a graphite crucible, placing into a high-temperature furnace, heating to 1300 plus 1600 ℃ (depending on components), and preserving heat for 0.5-2h to complete connection.

Example 1

The invention relates to a method for connecting a SiC composite material cladding tube and an end plug, which comprises the following steps:

the method comprises the following steps: mixing SiO₂、Al₂O₃And Y₂O₃Weighing and proportioning 3 oxides in a weight ratio of SiO₂ 42％wt.％，Al₂O₃25％wt.％，Y₂O₃ 33％wt.％；

Step two: mixing the mixed SiO₂、Al₂O₃And Y₂O₃3 raw materials are put into a ball milling tank, and are ball milled on a planetary ball mill with the ball milling revolution number of 300r/min for 2 hours;

step three: putting the ball-milled raw materials into a stainless steel mold, performing pressure molding on the stainless steel mold on a 60T press, pressing the mixture into a cylinder with the phi of 30mm, keeping the pressure at 20T for 10 s;

step four: putting the pressed cylinder into a graphite crucible, putting the graphite crucible into a high-temperature furnace, heating to 1650 ℃ for reaction, keeping the temperature for 2 hours, taking out the cylinder, and quickly putting the cylinder into water to obtain a vitreous body;

step five: putting the prepared glass body into a stainless steel ball milling tank, and carrying out ball milling on a planetary ball mill to prepare powder, wherein the ball milling revolution is 300r/min, and the ball milling lasts for 1 h;

step six: screening the ball-milled powder on a 150-mesh sieve, and taking the screened fine powder to obtain the required brazing filler metal;

step seven: cleaning and drying a cladding tube and an end plug to be connected, and fully mixing the prepared brazing filler metal and absolute ethyl alcohol according to the mass ratio of 1: 3;

step eight: uniformly brushing the brazing filler metal mixed with the ethanol on the inner surface of the cladding tube to be connected and the outer surface of the end plug, and embedding and combining the cladding tube and the end plug;

step nine: and (3) placing the combined cladding tube and end plug into a graphite crucible, placing into a high-temperature furnace, heating to 1500 ℃, and preserving heat for 1h to complete connection.

Example 2

The invention relates to a method for connecting a SiC composite material cladding tube and an end plug, which comprises the following steps:

the method comprises the following steps: mixing SiO₂、Al₂O₃And Y₂O₃Weighing and proportioning 3 oxides in a weight ratio of SiO₂ 45％wt.％，Al₂O₃24％wt.％，Y₂O₃ 31％wt.％；

Step two: mixing the mixed SiO₂、Al₂O₃And Y₂O₃3 raw materials are put into a ball milling tank, and are ball milled on a planetary ball mill with the ball milling revolution number of 300r/min for 2 hours;

step three: putting the ball-milled raw materials into a stainless steel mold, performing pressure molding on the stainless steel mold on a 60T press, pressing the mixture into a cylinder with the phi of 30mm, keeping the pressure at 20T for 10 s;

step four: putting the pressed cylinder into a graphite crucible, putting the graphite crucible into a high-temperature furnace, heating to 1600 ℃ for reaction, keeping the temperature for 2 hours, taking out the cylinder, and quickly putting the cylinder into water to obtain a vitreous body;

step five: putting the prepared glass body into a stainless steel ball milling tank, and carrying out ball milling on a planetary ball mill to prepare powder, wherein the ball milling revolution is 300r/min, and the ball milling lasts for 2 hours;

step six: screening the ball-milled powder on a 150-mesh sieve, and taking the screened fine powder to obtain the required brazing filler metal;

step seven: cleaning and drying a cladding tube and an end plug to be connected, and fully mixing the prepared brazing filler metal and absolute ethyl alcohol according to the mass ratio of 1: 3;

step eight: uniformly brushing the brazing filler metal mixed with the ethanol on the inner surface of the cladding tube to be connected and the outer surface of the end plug, and embedding and combining the cladding tube and the end plug;

step nine: and (3) placing the combined cladding tube and end plug into a graphite crucible, placing the graphite crucible into a high-temperature furnace, heating to 1480 ℃, and preserving heat for 1.5h to complete connection.

Example 3

The invention relates to a method for connecting a SiC composite material cladding tube and an end plug, which comprises the following steps:

the method comprises the following steps: mixing SiO₂、Al₂O₃And Y₂O₃Weighing and proportioning 3 oxides in a weight ratio of SiO₂ 48％wt.％，Al₂O₃26％wt.％，Y₂O₃ 26％wt.％；

Step two: mixing the mixed SiO₂、Al₂O₃And Y₂O₃3 raw materials are put into a ball milling tank, and are ball milled on a planetary ball mill with the ball milling revolution number of 300r/min for 2 hours;

step three: putting the ball-milled raw materials into a stainless steel mold, performing pressure molding on the stainless steel mold on a 60T press, pressing the mixture into a cylinder with the phi of 30mm, keeping the pressure at 20T for 10 s;

step four: putting the pressed cylinder into a graphite crucible, putting the graphite crucible into a high-temperature furnace, heating to 1500 ℃ for reaction, keeping the temperature for 2 hours, taking out the cylinder, and quickly putting the cylinder into water to obtain a vitreous body;

step five: putting the prepared glass body into a stainless steel ball milling tank, and carrying out ball milling on a planetary ball mill to prepare powder, wherein the ball milling revolution is 300r/min, and the ball milling lasts for 3 hours;

step six: screening the ball-milled powder on a 150-mesh sieve, and taking the screened fine powder to obtain the required brazing filler metal;

step seven: cleaning and drying a cladding tube and an end plug to be connected, and fully mixing the prepared brazing filler metal and absolute ethyl alcohol according to the mass ratio of 1: 3;

step eight: uniformly brushing the brazing filler metal mixed with the ethanol on the inner surface of the cladding tube to be connected and the outer surface of the end plug, and embedding and combining the cladding tube and the end plug;

step nine: and (4) placing the combined cladding tube and end plug into a graphite crucible, placing into a high-temperature furnace, heating to 1400 ℃, and preserving heat for 2 hours to complete connection.

The inner diameter of the silicon carbide composite material pipe is 8mm, and the outer diameter of the silicon carbide composite material pipe is 10 mm;

the silicon carbide ceramic end plug has an inner diameter of 8mm, an outer diameter of 10mm and a height of 10 mm.