JP2011157230A - Carbon fiber-reinforced carbon composite crucible and method for producing the crucible - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon fiber-reinforced carbon composite crucible which is used for supporting and holding a crucible containing a melt material in an apparatus for producing a single crystal or a polycrystal of a semiconductor material, a solar cell material or the like, wherein in a bottom curved portion, a stepped part of a wrinkle or an overlap is eliminated to improve durability. <P>SOLUTION: The carbon fiber-reinforced carbon composite crucible 1 includes a bottom portion 3 having a curved portion in a circumference portion and a straight body portion 2 extended upward from the curved portion of the bottom portion. The bottom portion 3 and the straight body portion 2 are formed by laminating a plurality of sheets of carbon fiber cloths 11, 12, 13 (10) having alternately woven warps and woofs of carbon fibers. The axial lines of the warps and wefts of the carbon fiber cloths at the curved portion of the bottom portion are formed in a direction oblique to the circumference direction of the crucible. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a carbon fiber reinforced carbon composite crucible and a method for producing the crucible, and, for example, a crucible for containing a molten material in a device for pulling up a single crystal such as a semiconductor material or a device for producing a polycrystal such as a solar cell material. The present invention relates to a carbon fiber reinforced carbon composite material crucible used for supporting and holding a crucible and a method for producing the crucible.

For example, when producing a single crystal such as a semiconductor material, the CZ method (Czochralski method) is widely used.
In this CZ method, as shown in FIG. 12, the seed crystal P is brought into contact with the surface of the silicon melt M accommodated in the quartz crucible 50, the quartz crucible 50 is rotated, and the seed crystal P is moved in the opposite direction. By pulling upward while rotating, the single crystal C is formed at the lower end of the seed crystal P.

As the silicon single crystal C is grown, the quartz crucible 50 is softened by the heat of the heater 52 and the heat of the silicon melt M. For this reason, the quartz crucible 50 is accommodated and supported in the graphite crucible 51.
When the pulling of the silicon single crystal is completed, the quartz crucible 50 and the graphite crucible 51 are cooled. At this time, since the coefficient of thermal expansion of the graphite crucible 51 is larger than that of the quartz crucible 50, the graphite crucible 51 is cracked and finally cracked and cracked when cooled in a state where they are in close contact with each other. was there.

For such a problem, for example, in Patent Document 1, instead of the conventional graphite crucible 51, a crucible made of a carbon fiber reinforced carbon composite material (also referred to as C / C material) (hereinafter referred to as a carbon crucible for convenience). ) Is disclosed. The coefficient of thermal expansion of the C / C material is close to that of the quartz glass crucible, and the mechanical strength is higher than that of the graphite material, so that the probability of occurrence of cracks during cooling can be greatly reduced.
And when manufacturing the carbon crucible disclosed by this patent document 1, as shown to Fig.13 (a), from the C / C material notched in the shape where several leaf-like bodies 60a continue in the upper part. A sheet-like carbon fiber woven fabric 60 is prepared. As shown in FIG. 13B, the prepared sheet-like carbon fiber woven fabric 60 is sequentially attached to the surface of the crucible forming die 61 in the manner of manufacturing a globe, and this operation is repeated until a predetermined thickness is obtained. To make.

Japanese Patent Laid-Open No. 11-60373

In the case of the carbon crucible manufactured by the method as shown in FIG. 13, the leaf-like bodies 60a are overlapped in the small curved portion R1 and the large curved portion R2 at the bottom of the crucible shown in FIG. The steps are formed radially.
In this way, since the leaf-like bodies 60a are superimposed on each other at the curved portions R1 and R2 at the bottom of the crucible, the SiO gas generated from the melt M in the furnace is caused by the curved portions R1 and R2 outside the carbon crucible 51. There was a problem that the layer stays in the stepped portion of the overlapped portion, and the portion is locally worn out, consumed and weakened by a chemical reaction (oxidation).
Further, since the outer wall surface of the quartz glass crucible and the inner peripheral surface of the carbon crucible are not completely in close contact with each other and there is a gap in part, the SiO gas enters through this gap, and the curved portion inside the carbon crucible 51 It stays at the stepped portion of the overlapping portion of R1 and R2. Even in this case, there is a problem that the portion is locally worn out, consumed and weakened by a chemical reaction (oxidation).
Thus, in the conventional carbon crucible, since the overlapping portions exist in the curved portions R1 and R2 of the carbon crucible 51, there is a problem that the carbon crucible is locally worn out and consumed, and the carbon crucible becomes weak. there were.

  The present invention has been made under the circumstances as described above, in order to support and hold a crucible containing a molten material in an apparatus for producing a single crystal such as a semiconductor material or a polycrystal such as a solar cell material. An object of the present invention is to provide a carbon fiber reinforced carbon composite crucible that has improved durability by eliminating a wrinkle or overlapping stepped portion at the bottom curved portion.

  The carbon fiber reinforced carbon composite crucible according to the present invention made to solve the above-described problems is a carbon fiber having a bottom portion having a curved portion at a peripheral portion and a straight body portion extending upward from the bottom curved portion. A reinforced carbon composite crucible, wherein the bottom part and the straight body part are formed by bonding a plurality of carbon fiber woven fabrics in which carbon fiber warp and weft are alternately woven, and at least the bottom curve The axis of the warp and weft yarns of the carbon fiber woven fabric located in the section is formed in an oblique direction with respect to the crucible circumferential direction.

In this way, in the bottom curved part, the warp and weft of the carbon fiber woven fabric are inclined with respect to the circumferential direction of the crucible, so that large irregularities such as double stitches and wrinkles are formed. It can be molded without any fiber breaks.
Therefore, when this carbon fiber reinforced carbon composite material crucible is used, SiO gas does not stay inside and outside the bottom curved portion of the crucible, and weakening due to chemical reaction (oxidation) can be suppressed.

  Here, the bottom and the curved portion of the bottom are made of an integral first carbon fiber woven fabric, and a warp and a weft of carbon fiber are crucible in the curved portion of the bottom and the straight body. It is preferable to use a second carbon fiber woven fabric formed so as to be inclined with respect to the circumferential direction.

Furthermore, a third carbon fiber woven fabric formed so that the weft yarns and warps of the carbon fibers are in a direction perpendicular to and parallel to the circumferential direction of the crucible is used for the straight body portion. It is preferable that the second carbon fiber woven fabric and the third carbon fiber woven fabric are alternately laminated.
Thus, when the weft and warp of the carbon fiber of the third carbon fiber woven fabric are formed so as to be in the direction parallel to and perpendicular to the circumferential direction of the crucible, the second carbon fiber woven fabric and the carbon fiber to be laminated are laminated. Since the directions are different, the strength can be improved. That is, by alternately laminating carbon fiber woven fabrics having different axial directions of warp and weft, mutual adhesive strength can be enhanced and the crucible rigidity can be improved.

  The third carbon fiber woven fabric may be formed such that the carbon fiber warp and weft are oblique to the circumferential direction of the crucible. When the warp and weft of carbon fiber of the third carbon fiber woven fabric are formed so as to be inclined with respect to the circumferential direction of the crucible, the direction of the second carbon fiber woven fabric to be laminated is the same as the carbon fiber, and the circumferential direction of the crucible The strength against tensile stress can be further improved.

The carbon fiber woven fabrics are preferably laminated so that discontinuities in the crucible circumferential direction of the carbon fiber woven fabrics laminated on the straight body portion do not overlap in the lamination direction.
In this way, between the overlapping carbon fiber woven fabrics, the discontinuous portions in the circumferential direction of the carbon fiber woven fabric do not overlap in the stacking direction, thereby reducing the gap in the stacking direction (thickness direction), The amount of carbon fibers in the stacking direction in the straight body portion can be made more uniform.

  The second carbon fiber woven fabric or the third carbon fiber woven fabric is preferably an integral type without any breaks, and it is desirable to wind the straight body part one or more times. Further, even when the size of the second carbon fiber woven fabric or the third carbon fiber woven fabric is less than the outer peripheral length of the straight body portion, the seam of the second carbon fiber woven fabric ( It is preferable that a discontinuous portion of the carbon fiber woven fabric in the crucible circumferential direction) and a seam of the third carbon fiber woven fabric (a discontinuous portion of the carbon fiber woven fabric in the crucible circumferential direction) overlap at different positions. .

Further, at least one of the straight body portion and the bottom portion, the carbon fiber woven fabrics are arranged so that the intersecting portions of the warp yarns and weft yarns of the carbon fiber woven fabrics laminated on the straight body portion do not overlap in the lamination direction. It is preferable that the woven fabric is laminated.
In this way, between the overlapping carbon fiber woven fabrics, the intersections of the warp and weft yarns do not overlap in the laminating direction, so that the unevenness of the portion where the warp yarns and the weft yarns intersect each other, and the overlapping carbon fiber woven fabrics The adhesive strength of can be strengthened.

  The carbon fiber reinforced carbon composite crucible manufacturing method according to the present invention, which has been made to solve the above-described problems, is characterized in that the carbon fiber woven fabric is bonded using a mixed adhesive of a thermosetting resin and carbon powder. Then, it is formed by performing a thermosetting treatment, a carbonization treatment, a graphitization treatment and a high-purification treatment.

  According to the present invention, it is possible to obtain a carbon fiber-reinforced carbon composite crucible having excellent durability by eliminating the wrinkles or overlapping stepped portions in the bottom curved portion. Moreover, according to this invention, the manufacturing method which can manufacture a carbon fiber reinforced carbon composite material crucible suitably can be obtained.

FIG. 1 is a plan view of a carbon fiber cloth used in a carbon fiber reinforced carbon composite crucible according to the present invention. FIG. 2 is a perspective view showing an embodiment of the carbon fiber-reinforced carbon composite crucible according to the present invention. FIG. 3 is a conceptual diagram of a horizontally-long rectangular carbon fiber woven fabric in which carbon fibers are knitted in a lattice shape vertically and horizontally. FIG. 4 is a conceptual diagram of a carbon fiber woven fabric having a circular shape in which carbon fibers are knitted in an oblique lattice shape with an inclination of 45 degrees. FIG. 5 shows a horizontally-long rectangular carbon fiber woven fabric in which carbon fibers are knitted in an oblique lattice shape of 45 degrees. FIG. 6 is a flow chart showing a manufacturing process of the carbon fiber reinforced carbon composite crucible shown in FIG. FIG. 7 is a diagram for explaining a manufacturing process of the carbon fiber reinforced carbon composite material crucible shown in FIG. 1. FIG. 8 is a diagram for explaining a manufacturing process of the carbon fiber reinforced carbon composite material crucible shown in FIG. 1. FIG. 9 is a diagram for explaining a manufacturing process of the carbon fiber-reinforced carbon composite material crucible shown in FIG. 1. FIG. 10 is a diagram for explaining a manufacturing process of the carbon fiber reinforced carbon composite material crucible shown in FIG. 1. FIG. 11 is a conceptual diagram of a carbon fiber woven fabric for explaining a preferred method of laminating the carbon fiber woven fabric in another embodiment of the carbon fiber reinforced carbon composite crucible according to the present invention. FIG. 12 is a view for explaining a crucible used in a silicon single crystal pulling apparatus. FIG. 13 is a view for explaining a conventional method for producing a carbon fiber reinforced composite crucible.

Hereinafter, embodiments of a carbon fiber reinforced carbon composite crucible according to the present invention will be described with reference to the drawings.
First, based on FIG. 1, the carbon fiber cloth used for this carbon fiber reinforced carbon composite material crucible will be described.
The carbon fiber woven fabric 10 is a carbon fiber woven fabric that is woven alternately with 1000 to 36000 carbon fibers having a diameter of 3 μm to 15 μm as warp yarns 10a and 1000 to 36000 carbon fibers with a diameter of 3 μm to 15 μm as weft yarns 10b. The weight per unit area is 80 g / m ^{2 to} 1000 g / m ² and the thickness is 0.1 mm to 0.8 mm.
Since the carbon fiber woven fabric 10 weaves the warp yarns 10a and the weft yarns 10b alternately as described above, the carbon fiber woven fabric 10 extends in the P direction (45 ° direction with respect to the axes of the warp yarn 10a and the weft yarn 10b) shown in FIG. It has the property to do. In addition, with respect to the directions of the warp yarn 10a and the weft yarn 10b, the elongation of the carbon fiber itself is only allowed.

Next, an embodiment of the carbon fiber reinforced carbon composite crucible 1 (hereinafter referred to as carbon crucible 1) according to the present invention will be described with reference to FIG. The carbon fiber reinforced carbon composite material in FIG. 2 is conceptually represented.
The carbon crucible 1 is a crucible used for supporting and holding a quartz crucible containing a silicon melt, for example, in a single crystal pulling apparatus (not shown) for pulling a single crystal such as a semiconductor material. .

The carbon crucible 1 has a straight body portion 2 and a bottom portion 3, the bottom portion 3 is formed to be curved, and a small curved portion R 1 (bottom portion curved portion) that is curved at a predetermined curvature at a peripheral portion thereof, and a center of the bottom portion. And a large curved portion R <b> 2. The straight body portion 2 extends upward from the small curved portion R1 of the bottom portion 3 in a cylindrical shape.
The carbon crucible 1 carries a plurality of the above-described carbon fiber cloths 10 and carries and adheres a mixed adhesive (not shown) of a thermosetting resin and carbon powder (for example, graphite powder), and then thermosetting, It is formed by performing carbonization, graphitization, and high-purification treatment. That is, the carbon crucible 1 is formed of a carbon fiber reinforced carbon composite material (hereinafter referred to as C / C material).
Specifically, the sheet-like carbon fiber woven fabrics 11, 12, and 13 shown in FIGS. 3 to 5 are bonded to a plurality of layers and subjected to thermosetting, carbonization, graphitization, and high-purification treatment. It is formed.

Here, the carbon fiber woven fabric 11 shown in FIG. 3 is formed so that the carbon fiber fabric 10 becomes a carbon fiber woven fabric having a carbon fiber axis in the vertical and horizontal directions (vertical and horizontal directions) and a horizontally long rectangular shape. This is a cut piece (third carbon fiber woven fabric). The width dimension w1 of the carbon fiber woven fabric 11 is formed to a length that can cover at least the outer periphery of the straight body portion 2 of the carbon crucible 1, and the height dimension h1 is the height dimension of the straight body portion 2. It is formed to have the same dimensions.
Further, the carbon fiber woven fabric 11 can be extended in the P direction shown in FIG. 3 (direction of 45 degrees with respect to the axes of the warp yarn 10a and the weft yarn 10b).

Also, the carbon fiber woven fabric 12 shown in FIG. 4 is obtained by cutting the carbon fiber woven fabric 10 so as to be a perfect circular carbon fiber woven fabric (first carbon fiber woven fabric). The diameter d of the carbon fiber woven fabric 12 is formed so as to cover the bottom 3 of the carbon crucible 1.
Further, the carbon fiber woven fabric 12 can be extended in the P direction (direction of 45 degrees with respect to the axes of the warp yarn 10a and the weft yarn 10b) shown in FIG.

Further, the carbon fiber woven fabric 13 shown in FIG. 5 is obtained by changing the carbon fiber woven fabric 10 into a carbon fiber woven fabric having a carbon fiber axis (warp and weft axes) obliquely at 45 degrees and a horizontally long square shape. (Second carbon fiber woven fabric). The width dimension w2 of the carbon fiber woven fabric 13 is formed to a length that can cover the outer periphery of the straight body portion 2 of the carbon crucible 1 like the carbon fiber woven cloth 11, and the height dimension h2 is defined as the straight body. It is longer than the height dimension of the part, specifically, it is formed to a length that can cover the small curved part R1 of the bottom part 3 in addition to the straight body part 2.
Further, the carbon fiber woven fabric 13 can be extended in the P direction (direction of 45 degrees with respect to the axes of the warp yarn 10a and the weft yarn 10b) shown in FIG.

Next, the manufacturing process of the carbon crucible 1 will be described with reference to FIG.
First, as shown in FIG. 7, a crucible molding die 5 is prepared, and a mixed adhesive (not shown) of a thermosetting resin and carbon powder (for example, graphite powder) is supported on the straight body portion 6 thereof, The carbon fiber woven fabric 11 is wound (step S1 in FIG. 6).
Here, the axial direction of carbon fibers of the carbon fiber woven fabric 11 (axial direction of warp and weft) is parallel to and perpendicular to the crucible circumferential direction T (axial direction of the crucible).
At this time, the carbon fiber woven fabric 11 does not extend in a direction parallel to the crucible circumferential direction T indicated by an arrow in FIG. 7 and does not extend in a direction orthogonal to the crucible circumferential direction T (the crucible axial direction). Since the diameter of the trunk portion 6 does not change, the carbon fiber woven fabric 11 can be adhered to the straight trunk portion 6 without any defects.
As shown in FIG. 10, the lower end portion 11 a of the carbon fiber woven fabric 11 is attached in a state of protruding downward from the crucible mold 5.

Next, as shown in FIGS. 7 and 8, the mixed adhesive is supported on the bottom 7 of the crucible mold 5 and a circular carbon fiber woven fabric 12 is attached and covered to form the bottom 3 (step S2 in FIG. 5). ).
Here, the carbon fiber woven fabric 12 is not a conventional carbon fiber woven fabric having a cut shape like a leaf (see FIG. 13), but an integral carbon fiber woven fabric having no cut. Further, the boundary portion between the carbon fiber woven fabric 11 that forms the straight body portion 2 of the carbon crucible 1 and the carbon fiber woven fabric 12 that forms the bottom portion 3 is not overlapped and is pasted so as not to cause a gap. Done.

When the circular carbon fiber woven fabric 12 is attached, the small curved portion R1 is covered with the peripheral portion of the carbon fiber woven fabric 12, but the carbon fiber woven fabric 12 has a carbon fiber axis (warp, Affixing is performed while extending obliquely 45 degrees with respect to the axis of the weft.
More specifically, the center portion of the carbon fiber woven fabric 12 is first attached to the center of the bottom portion 7 of the crucible molding die 5 and is attached so as to cover the small curved portion R1 while pulling the peripheral portion of the carbon fiber woven fabric 12. Is done.
At this time, the radius of the crucible mold 5 gradually increases from the center of the bottom, but the carbon fiber woven fabric 12 extends in a substantially oblique 45 degree direction with respect to the carbon fiber axis (warp, weft axis). The fiber woven fabric 12 can be pasted while being stretched. Thereby, the carbon fiber woven fabric 12 is stuck without any wrinkles in the small curved portion R1.

Then, the above-mentioned mixed adhesive is carried on the bonded carbon fiber woven fabrics 11 and 12, and as shown in FIG. A carbon fiber woven fabric 13 is attached so as to cover the trunk portion 6) and the small curved portion R1 formed by the carbon fiber woven fabric 12 (step S3 in FIG. 6).
In attaching the carbon fiber woven fabric 13, the radius gradually increases toward the outer peripheral portion of the crucible forming die 5 in the small curved portion R1, but the carbon fiber woven fabric 13 with respect to the circumferential direction T of the crucible as shown in the figure. Since the axes (warp and weft axes) are formed in an oblique 45 degree direction, the carbon fiber woven fabric 13 can be applied without wrinkles by being applied while being stretched.
Moreover, in the straight body part 2, since the axial direction of the carbon fiber is different from that of the underlying carbon fiber woven fabric 11 on which the mixed adhesive is carried, the adhesive force is strengthened and the rigidity is improved.

Further, when the carbon fiber woven fabric 13 is laminated on the carbon fiber woven fabric 11 in this manner, the discontinuous portions (end portions in the circumferential direction) of the carbon fiber woven fabrics 11 and 13 in the circumferential direction of the crucible are stacked in the stacking direction ( It is preferable to shift the position in the crucible circumferential direction so as not to overlap in the radial direction.
Moreover, in that case, it is preferable to affix so that the intersection part of the warp yarn 10a and the weft yarn 10b may not overlap in the lamination direction.
By laminating in this way, gaps in the laminating direction (thickness direction) are reduced, and the amount of carbon fibers in the laminating direction in the straight body portion 2 can be made more uniform.
Further, since the intersecting portion of the warp yarn 10a and the weft yarn 10b does not overlap in the laminating direction, the unevenness of the portion where the warp yarn 10a and the weft yarn 10b intersect is engaged, and the adhesive strength between the overlapping carbon fiber woven fabrics 11 and 13 is strengthened. be able to.

Such a carbon fiber woven fabric 11, 12, and 13 affixing step is repeated a plurality of times as shown in the cross-sectional view of FIG. 10 (three times in FIG. 10), and laminated to a predetermined thickness. (Step S4 in FIG. 6).
When all the carbon fiber woven fabrics 11, 12, and 13 are attached (laminated), the lower end portion 11a (the upper end portion when the crucible is used) of the innermost carbon fiber woven fabric 11 is folded in the direction of the arrow shown in FIG. Bending and pasting so as to cover the end of the crucible, an end forming process is performed (step S5 in FIG. 6).

Thus, when a crucible-type preform is obtained, it is placed in a vacuum furnace in a state where it is attached around the crucible mold 5 and heat-cured at a temperature of 100 ° C. to 300 ° C. (FIG. 6). Step S6).
Next, the crucible mold 5 is removed (step S7 in FIG. 6), and the resulting molded body is carbonized in an inert gas such as N ₂ gas at a temperature of about 1000 ° C. (step S8 in FIG. 6).
After the carbonization treatment, for example, a phenol resin, tar pitch or the like is impregnated and heated at a temperature of 1500 ° C. or higher to perform graphitization treatment (step S9 in FIG. 6).
Then, the crucible obtained by graphitization is usually heated to a temperature of 1500 ° C. to 2500 ° C. and subjected to a high-purification treatment to obtain a carbon crucible 1 made of a C / C material (step S10 in FIG. 6).

In the carbon crucible 1 obtained as described above, unevenness such as a step or a wrinkle is not formed in the overlapping portion in the curved portion at the bottom, and the small curved portion R1 from the straight body portion 2 as shown in FIG. Multi-layered continuously.
Therefore, since unevenness is not formed on the inside and outside of the bottom curved portion in the carbon crucible 1, the SiO gas generated in the furnace does not stay, and wear and consumption due to chemical reaction (oxidation) can be suppressed, and durability is improved. Can be improved. Further, by bonding a plurality of carbon fiber woven fabrics, a carbon crucible having a predetermined thickness can be manufactured, and durability can be improved.

In addition, in the said embodiment, in formation of the straight body part 2, the carbon fiber axis line is a longitudinal and transverse direction (straight body part axial direction, tangential direction perpendicular to the straight body part axis) with respect to the crucible circumferential direction. The fiber woven fabric 11 and the carbon fiber woven fabric 13 in which the axis of the carbon fiber is obliquely overlapped with the circumferential direction of the crucible at 45 degrees (the tangential direction intersecting at an angle of 45 degrees with respect to the straight body axis) are alternately stacked. did.
However, in the present invention, it is not limited to the form, and the straight body is formed by laminating only a plurality of carbon fiber woven fabrics 13 in which the axis of the carbon fiber is obliquely 45 degrees with respect to the circumferential direction of the crucible. The part 2 may be formed. Alternatively, the straight body portion 2 is formed by laminating a plurality of carbon fiber woven fabrics 11 in which the axis of the carbon fiber is longitudinal and transverse (straight body portion axial direction, tangential direction perpendicular to the straight body portion axis) with respect to the crucible circumferential direction. You may make it form.
By configuring the straight body portion 2 in this way, the strength against tensile stress in the crucible circumferential direction can be further improved.

  When the quartz crucible is heated, deformation occurs along the inner diameter of the carbon crucible due to softening of the crucible. Therefore, during cooling, a tensile stress in the circumferential direction of the crucible is generated due to the difference in thermal expansion coefficient between the quartz crucible and the carbon fiber woven fabric. Considering such tensile stress in the circumferential direction of the crucible, it is preferable to form the straight body portion 2 by laminating only a plurality of the carbon fiber woven fabrics 13.

Moreover, in that case, it is preferable to laminate the overlapping portions of the warp yarn 10a and the weft yarn 10b so that they do not overlap in the stacking direction between the overlapping carbon fiber woven fabrics 13. Specifically, when the carbon fiber woven fabric 13B (solid line) is pasted on the carbon fiber woven fabric 13A (broken line) positioned in the lower layer as schematically shown in FIG. 11 (a), FIG. 11 (b) As shown in FIG.
That is, as shown in FIG. 11 (b), the intersecting portion 10c between the warp yarn 10a and the weft yarn 10b of the carbon fiber woven fabric 13A indicated by a broken line, and the intersecting portion between the warp yarn 10a and the weft yarn 10b of the carbon fiber woven fabric 13B indicated by a solid line. 10d is made not to overlap in the stacking direction.

More preferably, as shown in FIG. 11B, in the carbon fiber woven fabric 13A located in the lower layer, the upper carbon fiber woven fabric 13B is formed at the center of the line segment d1 connecting the intersecting portions 10c adjacent in the crucible circumferential direction. Are stacked so that the intersecting portion 10d is located. Or it laminates | stacks so that the crossing part 10d in the upper layer carbon fiber woven fabric 13B may be located in the center of the line segment d2 which connects between the crossing parts 10c adjacent to the orthogonal direction with respect to the crucible circumferential direction.
Thereby, gaps in the stacking direction (thickness direction) are reduced, and the amount of carbon fibers in the stacking direction in the straight body portion 2 can be made more uniform. Moreover, since the unevenness | corrugation of the part which a warp and a weft cross | intersect meshes | engages, the adhesive force of the carbon fiber woven fabric 13 which overlaps can be strengthened.

DESCRIPTION OF SYMBOLS 1 Carbon fiber reinforced carbon composite material crucible 2 Straight body part 3 Bottom part 5 Crucible mold 6 Straight body part 7 Bottom part 10 Carbon fiber woven fabric 10a Warp yarn 10b Weft yarn 11 3rd carbon fiber woven fabric 12 1st carbon fiber woven fabric 13 Second carbon fiber woven fabric R1 Small curved portion (bottom curved portion)
R2 large bend

Claims (6)

A carbon fiber reinforced carbon composite crucible having a bottom part having a curved part at a peripheral part and a straight body part extending upward from the bottom curved part,
The bottom portion and the straight body portion are formed by bonding a plurality of carbon fiber woven fabrics obtained by alternately weaving carbon fiber warp yarns and weft yarns,
A carbon fiber reinforced carbon composite crucible, characterized in that at least the axes of warp and weft yarns of the carbon fiber woven fabric located at the bottom curved portion are formed obliquely with respect to the crucible circumferential direction. For the bottom and the bottom curved portion, an unbroken integral first carbon fiber woven fabric is used,
A second carbon fiber woven fabric formed so that warp yarns and weft yarns of carbon fibers are inclined with respect to the circumferential direction of the crucible is used for the bottom curved portion and the straight body portion. Item 2. A carbon fiber reinforced carbon composite crucible described in Item 1. Furthermore, a third carbon fiber woven fabric formed so that the weft yarn and warp yarn of the carbon fiber are in a direction perpendicular to the parallel direction to the circumferential direction of the crucible is used for the straight body portion,
The carbon fiber reinforced carbon composite material according to claim 2, wherein the second carbon fiber woven fabric and the third carbon fiber woven fabric are alternately laminated in the straight body portion. Crucible.   The carbon fiber woven fabrics are laminated so that discontinuities in the crucible circumferential direction of the carbon fiber woven fabrics laminated on the straight body portion do not overlap in the lamination direction. A carbon fiber-reinforced composite crucible according to any one of claims 3 to 4. In at least one of the straight body part and the bottom part,
The carbon fiber woven fabrics are laminated so that the intersecting portions of the warp and weft yarns of the carbon fiber woven fabrics laminated on the straight body portion do not overlap in the lamination direction. A carbon fiber-reinforced composite crucible according to any one of claims 4 to 4. A method for producing a carbon fiber reinforced carbon composite crucible according to any one of claims 1 to 5,
The carbon fiber woven fabric is bonded using a mixed adhesive of a thermosetting resin and carbon powder, and then formed by performing a thermosetting treatment, a carbonization treatment, a graphitization treatment and a high purification treatment. A method for producing a carbon fiber reinforced carbon composite crucible.

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