CN114919202A - Method for weaving carbon fiber composite material crucible preformed body and integrally forming carbon fiber composite material crucible preformed body and base - Google Patents

Abstract

The invention discloses a method for weaving a carbon fiber composite material crucible preformed body and integrally forming the carbon fiber composite material crucible preformed body and a base. The molding steps are as follows: calculating the number of carbon fiber weaving layers according to the structure and size requirements of the pre-forming body; the graphite base and the crucible core mold are fixed together through strong magnets, meanwhile, in the weaving process, weaving layers and net tires are alternately adopted, and meanwhile, the needling process is used, so that the connectivity between carbon fiber layers is improved. The integral forming method greatly enhances the structural performance of the crucible, reduces the raw material cost and the processing cost, and simultaneously prolongs the service life of the crucible.

Description

Carbon fiber composite crucible preform weaving and integral molding method with base

technical field

The invention relates to a carbon fiber composite material preform used for producing or producing single crystal silicon or polycrystalline silicon, in particular to a method for weaving and integrally forming a carbon fiber composite material preform with a base.

Background technique

In the production of single crystal silicon, the Czochralski method (CZ method) is generally used, that is, the single crystal silicon is pulled from the melt along the vertical direction. In the production process of single crystal silicon, one component is the graphite crucible, which is used to carry the inner single crystal silicon. Under the action of high temperature, the graphite crucible will have problems such as cracking, erosion and failure, so that the crucible cannot meet the normal use requirements. Moreover, with the growth of single-crystal silicon, the diameter of the crystal gradually increases, and in the process of increasing the diameter of the crystal, heat is transferred. Single crystal silicon has a high heat capacity, which leads to an increase in energy consumption during heat transfer, and requires higher structural performance of the crucible.

The existing crucible preform manufacturing method generally adopts the winding method, and the carbon fiber is wound into the shape of the crucible, and then the resin is impregnated, and finally a carbon/carbon fiber composite crucible is made. However, the wound preform is prone to stress concentration in structure, which affects the overall performance of the crucible.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: the preform formed by winding is prone to stress concentration phenomenon in structure, which causes the overall performance of the crucible to be affected.

In order to solve the above technical problems, the technical solution of the present invention is to provide a method for weaving and integrally forming a carbon fiber composite crucible preform with a base, which is characterized in that it includes the following steps:

Calculate the number of carbon fiber braided layers according to the structure and size requirements of the crucible preform;

The crucible base and the crucible core mold are integrally woven and formed, and the number of layers calculated by weaving n carbon fibers along the central axis of the crucible core mold is used, and the crucible base and the crucible core mold are integrally formed during the weaving process;

During the weaving process, the surface of the crucible base and the crucible core mold are alternately covered with carbon fiber weaving and mesh tires, and acupuncture is performed after the weaving is completed;

Before forming, the crucible mandrel is extracted from the carbon fiber, and the strong magnet and the braiding process clamping end are removed at the same time.

Preferably, the n carbon fibers are reciprocatingly braided by a three-dimensional braiding machine, and the core mold of the crucible preform reciprocates along the horizontal direction of the central axis of the crucible in the braiding ring of the three-dimensional braiding machine.

Preferably, the process of weaving the n carbon fibers along the central axis of the crucible is determined by the movement of the three-dimensional weaving machine.

Preferably, during the weaving process of the n carbon fibers along the central axis of the crucible, as the number of braiding layers increases, the length and thickness of the fibers increase layer by layer.

Preferably, a layer of carbon fiber braided layer is woven on the surface of the crucible core mold and then covered with a layer of carbon fiber mesh tire, and the carbon fiber mesh tire is alternately laid relative to the carbon fiber braided layer until the carbon fiber braided layer reaches the calculated number of carbon fiber braided layers; the carbon fiber mesh tire is composed of The carbon fiber short fibers are prepared in the form of cotton wool, and the carbon fiber mesh tires alternate with the carbon fibers of the carbon fiber braid to reduce the porosity of the braid.

Preferably, after the weaving is completed, needle punching is performed, so that the carbon fiber mesh body and the carbon fiber braided layer are integrated and maintain a relatively stable shape. The acupuncture uses special needles to penetrate the carbon fiber mesh tire and the carbon fiber braided layer, so that the carbon fibers of the carbon fiber mesh tire and the carbon fiber braided layer are better interlaced.

Preferably, the crucible base is made of graphite or quartz as the inner material, and the outside of the crucible base is woven with carbon fibers to cover the graphite or quartz surface. The carbon fiber covering includes the carbon fiber braided layer and the carbon fiber mesh tire, and the carbon fiber braided layer and the carbon fiber mesh tire are alternately covered on the crucible base.

Preferably, the crucible base is in the shape of an "I", including a bowl-shaped lower part and a bowl-shaped upper part, and the bowl-shaped lower part and the bowl-shaped upper part together form the crucible base, so that the carbon fiber braided layer and the carbon fiber mesh tire are interlaced and fixed. together.

Preferably, when weaving the crucible preform, strong magnets are respectively placed outside the crucible core mold and the crucible base to fix the crucible core mold and the crucible base. There are two said strong magnets, one is installed in the groove of the clamping end of the weaving process, together with the clamping end of the weaving process, and the other is placed in the upper part of the bowl, the two strong magnets attract each other magnetically, so as to maintain a stable form.

Preferably, the crucible core mold needs to be taken out after the weaving is completed. Since the surface of the crucible core mold and the crucible base are alternately covered with carbon fiber braided layers and carbon fiber mesh tires, the crucible core mold is beneficial to maintain the shape of the preform after taking out.

In order to improve the performance of the crucible, the present invention adopts the form of the carbon fiber composite preform and the base, and the graphite base and the crucible body are integrally woven to ensure that the bottom of the crucible has sufficient strength and heat resistance. Structurally, it solves the phenomenon of crucible erosion and cracking caused by high temperature melting of single crystal silicon in the crucible, which meets the needs of single crystal silicon or polycrystalline silicon production, and saves the production cost of the crucible. The crucible production efficiency.

Compared with the existing crucible, the carbon fiber composite material crucible preform weaving and integral molding method with the base of the present invention can improve the coating of carbon fiber on the surface of the crucible, enhance the strength of the crucible, improve the service life of the crucible, and at the same time can reduce the cost of raw materials. The crucible body adopts the method of weaving carbon fibers along the central axis of the crucible, and the middle is alternately covered with a mesh. After the weaving is completed, needle punching is performed to make the mesh body and the woven layer integrated and maintain a relatively stable shape. The defect of different strengths in all directions of the crucible caused by the preform produced by winding is avoided, and at the same time, the cohesive force of the surface carbon fibers is improved, so that the structural strength of the crucible preform is improved. The integrated molding method is adopted to enhance the connection performance between the crucible base and the crucible body and improve the service life of the product.

Description of drawings

1 is a cross-sectional view of a carbon fiber composite crucible preform;

2 is a cross-sectional view of the bottom structure of a carbon fiber composite crucible preform;

Fig. 3 is a schematic diagram of the carbon fiber composite crucible preform and the integrated weaving process with the base.

In the picture:

1. Crucible mandrel, 2. Crucible base, 3. Bowl-shaped lower part, 4. Bowl-shaped upper part, 5. Carbon fiber, 6. Clamping end for braiding process, 7. Strong magnet, 8. Braiding ring, 9. 3D braiding machine .

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

The invention discloses a method for weaving and integrally forming a crucible preform with a base, which can effectively improve the service life of the crucible in the manufacturing process of monocrystalline silicon or polycrystalline silicon. The obtained crucible preform comprises a crucible core mold 1, Crucible base 2, carbon fiber 5. The crucible core mold 1 is centered on the central axis of the crucible preform, has a U-shaped cross section, and is arranged in a ring shape.

The crucible base 2 is made of graphite or quartz as the inner material, and the outer layer of the crucible base 2 is woven with carbon fibers to cover the graphite or quartz surface. The carbon fiber covering comprises a carbon fiber braided layer and a carbon fiber mesh tire, and the carbon fiber braided layer and the carbon fiber mesh tire are alternately covered on the crucible base. The carbon fiber base 2 is in the shape of an "I", including a bowl-shaped lower part 3 and a bowl-shaped upper part 4 . Carbon fiber 5 is a multi-layer fiber, including carbon fiber braided layers and carbon fiber mesh tires alternated with fiber covering layers. Weaving a layer of carbon fiber braid on the surface of the crucible core mold, covering a layer of carbon fiber mesh tire. The carbon fiber mesh tire is made of a kind of carbon fiber, which is in the shape of cotton wool. The carbon fiber mesh tire alternates with the carbon fibers of the carbon fiber braided layer, which is beneficial to reduce the pores of the braided fabric. After the weaving is completed, needle punching is performed to make the carbon fiber mesh body and the carbon fiber braided layer integrated and maintain a relatively stable shape.

The crucible preform weaving and integral molding method with the base provided by the present invention connects the crucible core mold 1 and the crucible bottom 2 for weaving, and the integrated molding method can enhance the connection performance between the crucible bottom 2 and the crucible core mold 1 . The crucible preform is woven with carbon fibers. The carbon fiber braided layer and the carbon fiber mesh are alternately covered on the surface of the crucible core mold 1 and the crucible base 2. After the carbon fiber braided layers and thickness meet the requirements, the carbon fiber 5 is needled by acupuncture. , to improve the connection performance between the carbon fiber braid and the layer. Carbon fiber mesh is added between the carbon fiber braided layers to reduce the pores between the fibers, which can improve the covering of the crucible surface and ensure the same concentricity, thereby preventing the crucible preform from being deformed after the crucible core mold 1 is pulled out after the weaving is completed. Weaving a layer of carbon fiber braid on the surface of the crucible core mold, covering a layer of carbon fiber mesh tire. The carbon fiber mesh body is prepared from a carbon fiber short fiber and is in the shape of cotton wool. The carbon fiber mesh body and the carbon fibers of the braided layer alternate, which is beneficial to reduce the pores of the braided fabric. After the weaving is completed, needle punching is performed to make the carbon fiber mesh body and the carbon fiber braided layer integrated and maintain a relatively stable shape.

The acupuncture uses special needles to penetrate the carbon fiber mesh tire and the carbon fiber braided layer, so that the carbon fibers of the carbon fiber mesh tire and the carbon fiber braided layer are better interlaced.

The clamping end 6 in the weaving process is provided with a groove, and there are two strong magnets 7, one is installed in the groove of the clamping end in the weaving process, together with the clamping end 6 in the weaving process, and the other is placed on the bowl-shaped upper part 4, and the two Strong magnets are magnetically attracted to each other, thus maintaining a stable form.

A method for weaving a crucible preform and forming it integrally with a base disclosed in this embodiment specifically includes the following steps:

Step 1. Preliminary preparation: Determine the structure and size of the crucible preform according to the application scene and structural size of the crucible, and use carbon fiber as the raw material to calculate the braiding thickness and number of layers;

Step 2. Weaving work: fix the crucible core mold 1 , the crucible base 2 and the weaving process clamping end 6 by a strong magnet 7 , and then install the weaving process clamping end 6 on the three-dimensional weaving machine 9 . The crucible core mold 1 is used for reciprocating weaving movement along the central axis of the crucible through the braided ring 8. The carbon fibers 5 covered on the surfaces of the crucible core mold 1 and the crucible base 2 include carbon fiber braided layers and alternately laid carbon fiber mesh tires. One layer of carbon fiber braided layer is woven. , laying a layer of carbon fiber mesh tires. During the weaving process, after the crucible core mold 1 moves in the first direction to complete one stroke of weaving, a layer of carbon fiber mesh is laid on the braided layer, and the pulling direction of the three-dimensional braiding machine 9 is changed. The crucible core mold 1 is opposite to the initial direction. Move in the second direction, continue the weaving of the next stroke, after the weaving is completed, lay a layer of carbon fiber mesh again, and cycle back and forth until the weaving thickness reaches the calculated thickness in step 1. In the weaving process, a layer of carbon fiber braided layer is braided on the surface of the crucible core mold, and a layer of carbon fiber mesh tire is covered. The carbon fiber mesh tire is prepared from a kind of carbon fiber short fibers, and is in the shape of cotton wool. The carbon fiber mesh tire and the carbon fibers of the carbon fiber braided layer are alternated, which is beneficial to reduce the pores of the braided fabric. After the weaving is completed, needle punching is performed to make the carbon fiber mesh body and the carbon fiber braided layer integrated and maintain a relatively stable shape. The acupuncture uses special needles to penetrate the carbon fiber mesh tire and the carbon fiber braided layer, so that the carbon fibers of the carbon fiber mesh tire and the carbon fiber braided layer are better interlaced.

Step 3. Crucible molding: resin molding is performed on the woven crucible preform. Before forming, the crucible core mold 1 is extracted from the carbon fiber 5, and the strong magnet 7 and the clamping end of the weaving process are disassembled at the same time. The crucible base 2 is covered with carbon fibers, left in the carbon fibers 5, and formed together.

In the later stage of processing, a part of the outer side of the braided preform body will be cut off, and the crucible preform formed by ordinary winding may have the phenomenon that the fibers are detached from the crucible body. The one-piece molding method can effectively avoid the occurrence of this phenomenon.

Therefore, the method of weaving and integrally forming the composite crucible preform adopted in the present invention can greatly improve the strength of the crucible, save the raw material and processing cost of the crucible preform, and at the same time increase the service life of the crucible.

Finally, it should be noted that the above implementation is not a limitation but only illustrates the technical solution of the present invention. Experts and technicians in the field should understand that the solution modification or technical replacement can be carried out on the basis of the present invention without departing from the technical solution of the present invention. The spirit and requirements shall be included in the scope of the claims of the present invention.

Claims (7)

1. A method for weaving a carbon fiber composite material crucible preforming body and integrally forming the carbon fiber composite material crucible preforming body and a base is characterized by comprising the following steps of:

calculating the number of carbon fiber woven layers according to the structure and size requirements of the crucible preformed body;

integrally weaving a crucible base and a crucible core mold, wherein the crucible core mold adopts n carbon fibers to weave the calculated number of layers along the central axis of the crucible, and the crucible base and the crucible core mold are integrally woven in the weaving process;

in the weaving process, the surfaces of the crucible base and the crucible core mold are alternately covered by carbon fiber weaving and net tire, and needling is performed after weaving is finished;

before forming, the crucible core mold is extracted from the carbon fiber weaving, and the strong magnet and the clamping tail end in the weaving process are detached simultaneously.

2. The method for knitting a carbon fiber composite crucible preform and integrally forming the same with a base as claimed in claim 1, wherein the method for knitting n carbon fibers in a reciprocating manner by using a three-dimensional knitting machine, and the crucible preform core mold is reciprocated in a horizontal direction along a central axis of the crucible in a knitting ring of the three-dimensional knitting machine.

3. The method for knitting a carbon fiber composite crucible preform and integrally forming the carbon fiber composite crucible preform with a base as claimed in claim 1, wherein the knitting of the n carbon fibers along the central axis of the crucible is determined by the movement of a three-dimensional knitting machine, and the fiber length and the thickness increase layer by layer as the number of knitting layers increases.

4. The method for knitting a carbon fiber composite crucible preform and integrally forming the carbon fiber composite crucible preform and a base as claimed in claim 1, wherein a carbon fiber woven layer is woven on the surface of the crucible mandrel and then covered with a carbon fiber net tire, the carbon fiber net tire is alternately laid with respect to the carbon fiber woven layer until the carbon fiber woven layer reaches the calculated number of carbon fiber woven layers; the carbon fiber net tire is prepared from carbon fiber short fibers and is cotton-shaped, and the carbon fiber net tire and the carbon fiber woven layer short carbon fibers are alternated to reduce the pores of the braided fabric.

5. The method for knitting a carbon fiber composite crucible preform and integrally forming the carbon fiber composite crucible preform and a base as claimed in claim 1, wherein after the knitting is completed, the needling is performed to integrate the carbon fiber mesh and the carbon fiber woven layer and to maintain a relatively stable shape; the needling adopts the needles to penetrate into the carbon fiber net tire and the carbon fiber woven layer, so that the carbon fibers of the carbon fiber net tire and the carbon fiber woven layer are better staggered.

6. The method for weaving the carbon fiber composite crucible preform and integrally forming the carbon fiber composite crucible preform and the base as claimed in claim 1, wherein the crucible base is made of graphite or quartz as an inner material and is in an I shape comprising a bowl-shaped lower part and a bowl-shaped upper part.

7. The method for knitting a carbon fiber composite crucible preform and integrally forming the preform and the base as claimed in claim 6, wherein before knitting, strong magnets are respectively added into the crucible core mold and the grooves at the clamping ends in the knitting process, and the two strong magnets attract each other, thereby fixing the crucible base and the crucible core mold together; after weaving, the strong magnet is detached, and the crucible core mold is taken out in a stretching mode.

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