JP2009155203A - Carbon fiber-reinforced carbon composite and component for pulling single crystal apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a C/C composite which is formed by continuously performing CVI and CVD to impregnate and coat pyrolytic carbon, and can exhibit excellent SiC resistance, and to provide a component for a single crystal pulling apparatus. <P>SOLUTION: A pitch or a resin is beforehand impregnated into a C/C composite base material for densification, thereafter, it is continuously subjected to CVI and CVD treatment in the same furnace and in the same process, thus the density difference between a coated pyrolytic carbon layer and an impregnated pyrolytic carbon layer and the average surface roughness of the coated layer are controlled, and both the layers are continuously formed, so as to secure its SiC resistance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、炭素繊維強化炭素複合材に関し、特に熱分解炭素が含浸、被覆されたものに関する。   The present invention relates to a carbon fiber reinforced carbon composite material, and more particularly to a material impregnated and coated with pyrolytic carbon.

チョクラルスキー法（以下、ＣＺ法という）に用いられる単結晶引き上げ装置は、単結晶の大口径化に伴い、前記装置自身も大型化の傾向にある。前記装置内の高温雰囲気下で使用される部材としては、従来から機械的強度及び耐熱性に優れた等方性で高密度かつ高純度の黒鉛が用いられてきた。そして、装置の大型化に伴い、黒鉛部材も大型化し、そのために、黒鉛部材も厚肉化せざるを得ず、黒鉛部材の重量増加ひいては炉内有効寸法の減少によるハンドリング性能の低下につながるという問題がある。   A single crystal pulling apparatus used for the Czochralski method (hereinafter referred to as CZ method) tends to increase in size as the diameter of the single crystal increases. As a member used in a high-temperature atmosphere in the apparatus, an isotropic, high-density and high-purity graphite having excellent mechanical strength and heat resistance has been conventionally used. And with the increase in the size of the equipment, the graphite member also becomes larger. For this reason, the graphite member also has to be thickened, which leads to an increase in the weight of the graphite member and consequently to a reduction in handling performance due to a decrease in the effective dimensions in the furnace. There's a problem.

そこで、黒鉛部材よりも軽量でありながら同等以上の機械的強度を有する炭素繊維強化炭素複合材（以下、Ｃ／Ｃ材という）が注目され、単結晶引き上げ装置の黒鉛製高温部材の代替として要請されている。   Accordingly, carbon fiber reinforced carbon composite materials (hereinafter referred to as C / C materials) that are lighter than graphite members and have mechanical strength equal to or higher than that of the graphite members have been attracting attention, and requested as an alternative to graphite high temperature members for single crystal pulling equipment. Has been.

しかしながら、Ｃ／Ｃ材は表面の比表面積が大きく、気孔も大きいため、装置内に充満する溶融シリコンから発生するＳｉＯガスと反応し易く、黒鉛に比較するとＳｉＣ化する進展速度が早いという問題がある。   However, since the C / C material has a large specific surface area and large pores, it easily reacts with SiO gas generated from molten silicon filled in the apparatus, and has a problem that the rate of progress of SiC conversion is higher than that of graphite. is there.

そのため、このＳｉＯガスとの反応を抑える方法として、本出願人によりＣＺ装置用ルツボとしてＣ／Ｃ材にＣＶＩ法による熱分解炭素の含浸と被覆を行う方法(下記特許文献１参照)が提案されている。しかしながら、ＣＶＩ法のみにより熱分解炭素を含浸、被覆した場合、含浸層は深くまで形成できるが、表面に形成されている被覆層は薄く、表面の比表面積が大きく、気孔が皆無でないため、耐ＳｉＣ化が不十分であった。また、ＣＶＤ法のみにより熱分解炭素を被覆、含浸した場合は、前記ＣＶＩ法の場合とは逆に、表面の被覆層は厚く形成でき、耐ＳｉＣ化も向上する。しかしながら、表面の熱分解炭素被覆層が損耗した場合、内部の含浸層が薄いため、Ｃ／Ｃ材のＳｉＣ化が一気に進行するおそれがあり、安全性の面から単結晶引き上げ装置用部材への適用には不安が残る。   Therefore, as a method for suppressing the reaction with the SiO gas, the present applicant has proposed a method of impregnating and coating pyrolytic carbon on the C / C material by the CVI method as a crucible for a CZ apparatus (see Patent Document 1 below). ing. However, when impregnated and coated with pyrolytic carbon only by the CVI method, the impregnated layer can be formed deep, but the coating layer formed on the surface is thin, the surface has a large specific surface area, and there are no pores. SiC conversion was insufficient. Further, when the pyrolytic carbon is coated and impregnated only by the CVD method, contrary to the CVI method, the surface coating layer can be formed thick and the SiC resistance is improved. However, when the pyrolytic carbon coating layer on the surface is worn out, the impregnated layer inside is thin, so there is a risk that the C / C material will be converted to SiC at a stretch. Uncertainties remain in application.

国際公開第１９９７／４９８４４号International Publication No. 1997/49844

そこで、本発明の目的は、熱分解炭素をＣＶＩ、ＣＶＤを連続的に行い、Ｃ／Ｃ材に含浸、被覆し、優れた耐ＳｉＣ化を発揮できるＣ／Ｃ材、及びそれにより形成された単結晶引き上げ装置用部材を提供することにある。   Accordingly, an object of the present invention is a C / C material that can continuously exhibit pyrolytic carbon by CVI and CVD, impregnate and coat the C / C material, and exhibit excellent resistance to SiC, and formed thereby. The object is to provide a member for a single crystal pulling apparatus.

前記問題を解決するために、本発明者らはＣＶＩ法、ＣＶＤ法の両者の利点を利用することにより、すなわち、ＣＶＩ処理し、その後連続的にＣＶＤ処理を施し、熱分解炭素を含浸、被覆することにより、被覆層の耐剥離性が向上することを見出し、本発明の完成に至った。   In order to solve the above problems, the present inventors have made use of the advantages of both the CVI method and the CVD method, that is, CVI treatment, followed by continuous CVD treatment, impregnated and coated with pyrolytic carbon. As a result, it was found that the peel resistance of the coating layer was improved, and the present invention was completed.

すなわち、本発明の請求項１の発明は、ピッチ及び／又は樹脂の含浸により緻密化した後、ＣＶＩにより熱分解炭素の含浸層を形成し、更に前記含浸層の上にＣＶＤにより熱分解炭素の被覆層を形成してなり、前記被覆層の平均面粗さが５ μｍ 以下である炭素繊維強化炭素複合材である。熱分解炭素をＣＶＩ法により含浸すると、表層部付近の気孔及び各繊維による段差が埋まり、表面に熱分解炭素をＣＶＤ法で被覆した場合に滑らかな面を形成することが可能となる。   That is, according to the first aspect of the present invention, after densification by impregnation with pitch and / or resin, a pyrolytic carbon impregnation layer is formed by CVI, and further, pyrolytic carbon is formed on the impregnation layer by CVD. A carbon fiber reinforced carbon composite material comprising a coating layer, wherein the coating layer has an average surface roughness of 5 μm or less. When the pyrolytic carbon is impregnated by the CVI method, pores in the vicinity of the surface layer portion and steps due to the fibers are filled, and a smooth surface can be formed when the pyrolytic carbon is coated on the surface by the CVD method.

また、平均面粗さを５μｍ以下とすることで、ＳｉＯガスとの接触面積を小さくすることができ、ＳｉＣ化を抑制することができる。   Moreover, by making average surface roughness 5 micrometers or less, a contact area with SiO gas can be made small and SiC-ized can be suppressed.

請求項２の発明は、前記含浸層及び前記被覆層の密度差が０．２ｇ／ｃｍ^３以下である請求項１記載の炭素繊維強化炭素複合材である。含浸層及び被覆層の密度差を０．２ｇ／ｃｍ^３以内、好ましくは０．１ｇ／ｃｍ^３以内とすることで、含浸層と被覆層との明確な境界がなくなり、被覆層の耐剥離性の向上に寄与する。 The invention according to claim 2 is the carbon fiber reinforced carbon composite material according to claim 1, wherein the density difference between the impregnation layer and the coating layer is 0.2 g / cm ³ or less. By setting the density difference between the impregnated layer and the coating layer to be within 0.2 g / cm ³ , and preferably within 0.1 g / cm ³ , there is no clear boundary between the impregnating layer and the coating layer, and the peel resistance of the coating layer It contributes to the improvement.

請求項３の発明は、前記含浸層及び前記被覆層は、同一炉で連続的に形成された請求項１又は２に記載の炭素繊維強化炭素複合材である。同一炉で連続的に含浸層、被覆層が形成されるため、含浸層表面が外気に晒されることがないため、含浸層と被覆層の間に不純物等の介在物が介在することなく、含浸層と被覆層間の明確な境界の形成を抑制することができる。   The invention according to claim 3 is the carbon fiber reinforced carbon composite material according to claim 1 or 2, wherein the impregnation layer and the coating layer are continuously formed in the same furnace. Since the impregnation layer and coating layer are continuously formed in the same furnace, the surface of the impregnation layer is not exposed to the outside air, so that there is no inclusion such as impurities between the impregnation layer and the coating layer. The formation of a clear boundary between the layer and the covering layer can be suppressed.

請求項４の発明は、請求項１〜３のいずれか１項に記載の炭素繊維強化炭素複合材により形成された単結晶引き上げ装置用部材である。   Invention of Claim 4 is the member for single crystal pulling apparatuses formed with the carbon fiber reinforced carbon composite material of any one of Claims 1-3.

本発明はＣＶＤ層による被覆層が従来よりも厚く、耐ＳｉＣ化に優れた特性を有し、更に、ＣＶＩ法による含浸層の表面に被覆された被覆層であるために耐剥離性を併せて有するという効果を奏する。また、被覆層がＳｉＯガスにより浸食損耗した場合でも、含浸層によりＳｉＣ化の進行を阻止する効果も奏することができる。これに加えて、表面の面粗さを滑らかにすることができるため、ＳｉＣ化の進行を確実に抑制することができる。また、ＣＶＩ、ＣＶＤを連続的に行うことにより、含浸層と被覆層の境界が明確にならず、表面の被覆層の耐剥離特性が向上するという効果が得られる。また、工程の簡略化、品質の安定化を計ることができる。   In the present invention, the coating layer formed by the CVD layer is thicker than the conventional one, and has excellent characteristics in terms of SiC resistance. Further, since the coating layer is coated on the surface of the impregnated layer by the CVI method, the peeling resistance is also combined. It has the effect of having. In addition, even when the coating layer is eroded by the SiO gas, the impregnation layer can also have an effect of preventing the progress of SiC formation. In addition, since the surface roughness of the surface can be smoothed, the progress of SiC formation can be reliably suppressed. Further, by continuously performing CVI and CVD, the boundary between the impregnated layer and the coating layer is not clarified, and the effect of improving the peel resistance of the coating layer on the surface is obtained. In addition, the process can be simplified and the quality can be stabilized.

熱分解炭素の生成温度と密度の関係図。The relationship diagram of the generation temperature and density of pyrolytic carbon.

本発明におけるＣ／Ｃ材は、例えば、ピッチ系又はＰＡＮ系の炭素繊維を出発原料とするＵＤ又は２−Ｄに、樹脂を含浸させプリプレグにして積層、硬化させるか、前記炭素繊維をフィラメントワインディングで巻き付けて加熱、硬化させるか、３−Ｄ又はｎ−Ｄ織物に樹脂を含浸させて加熱、硬化させる等の方法によって成形体を形成する。ここで、最内層の炭素繊維は、３Ｋクロスの１枚貼りより、繊維密度が細かくて、ＳｉＯガスの浸透による酸化を少なくするために、１Ｋクロスの多層貼りが有利である。この成形体を還元雰囲気で炭化を行う。次にピッチ又は熱硬化性樹脂を含浸、焼成する処理を数回繰り返し、緻密化を行う。そして、緻密化処理後、引き続き高温で熱処理を行い黒鉛化処理を行う。ついで、高温（約２０００℃）でハロゲンガスと反応させて高純度化処理を行う。なお、黒鉛化処理と高純度化処理は同一炉で同時に行っても構わない。また、ピッチと熱硬化性樹脂を併用して緻密化を行っても構わない。   The C / C material in the present invention is, for example, UD or 2-D starting from pitch-based or PAN-based carbon fibers, impregnated with resin, laminated and cured, or filament-winding the carbon fibers. The molded body is formed by a method of winding and heating and curing, or impregnating a 3-D or n-D fabric with a resin and heating and curing. Here, the carbon fiber of the innermost layer has a finer fiber density than that of a single piece of 3K cloth, and multi-layer attachment of 1K cloth is advantageous in order to reduce oxidation due to permeation of SiO gas. This molded body is carbonized in a reducing atmosphere. Next, the process of impregnating and baking the pitch or thermosetting resin is repeated several times to perform densification. Then, after the densification treatment, heat treatment is continued at a high temperature to perform graphitization treatment. Next, a high purity treatment is performed by reacting with a halogen gas at a high temperature (about 2000 ° C.). Note that the graphitization treatment and the high-purification treatment may be performed simultaneously in the same furnace. Further, densification may be performed by using a pitch and a thermosetting resin in combination.

ついで、ＳｉＯガスとの反応を抑制することを目的に、ＣＶＩ法によって、熱分解炭素を含浸させる。これによって、表層部内部に残存する気孔を埋めることができる。ＣＶＩ法による熱分解炭素の含浸は、通常８００〜１３００℃、１０〜１００Ｔｏｒｒ（１３．３×１０^２〜１３．３×１０^３Ｐａ）の範囲下で、炭素数１〜８の炭化水素ガスを流量１０〜１００ｌ／ｍｉｎで供給し、所望の厚みに形成させるよう保持時間を調節する。この含浸層は、被覆層の剥離を防ぐ緩衝層としての役割を有しつつ、表面の被覆層が浸食、損耗した場合のＣ／Ｃ材のＳｉＣ化を防ぐ為にも少なくとも５〜２０μｍ 、更には５〜１０μｍであることが好ましい。これにより形成される含浸層の炭素組織は、主に柱状の細かい炭素組織（ＲＣ組織）となっている。 Next, pyrolytic carbon is impregnated by the CVI method for the purpose of suppressing reaction with SiO gas. As a result, pores remaining in the surface layer portion can be filled. The impregnation of pyrolytic carbon by the CVI method is usually performed at a temperature of 800 to 1300 ° C. and 10 to 100 Torr (13.3 × 10 ^{2 to} 13.3 × 10 ³ Pa) in a hydrocarbon gas having 1 to 8 carbon atoms. Supply is performed at a flow rate of 10 to 100 l / min, and the holding time is adjusted to form a desired thickness. This impregnated layer has a role as a buffer layer for preventing peeling of the coating layer, and at least 5 to 20 μm in order to prevent the C / C material from becoming SiC when the coating layer on the surface is eroded or worn. Is preferably 5 to 10 μm. The carbon structure of the impregnated layer thus formed is mainly a columnar fine carbon structure (RC structure).

表面の熱分解炭素の被覆層はＳｉＯガスとの反応を抑制するとともに、ＳｉＯガスの内部への浸透を防ぐために、ＣＶＤ法により形成する。ＣＶＤ処理は析出速度を大きく取るために、ＣＶＩ処理時の処理温度よりも高温、低圧で行う。ここで、高温にするほど炭素の理想密度に近づくことが知られているが、このような反応炉の場合、高温で使用するほど、製造コストが高くなる。これは本発明の目的の一つに反するため、本発明での処理温度は工業的に実施可能な温度である１５００〜２２００℃とし、処理圧力は１〜１０Ｔｏｒｒ（１３．３×１０^１〜１３．３×１０^２Ｐａ）の範囲下で、炭素数１〜８の炭化水素ガスを流量５〜５０ｌ／ｍｉｎで供給し、所望の厚みに形成させるよう保持時間を調節する。この被覆層は厚すぎると剥離する恐れがあり、また、ＳｉＯガスの内部への浸透を防ぐためにも薄すぎては良くなく、ＳｉＣ化する反応を遅らせるためにも少なくとも厚さが１０〜１００μｍ、更には、２０〜８０μｍであることが好ましい。 The surface pyrolytic carbon coating layer is formed by a CVD method in order to suppress reaction with SiO gas and prevent penetration of SiO gas into the interior. The CVD process is performed at a higher temperature and lower pressure than the processing temperature during the CVI process in order to increase the deposition rate. Here, it is known that the higher the temperature, the closer to the ideal density of carbon, but in the case of such a reactor, the higher the temperature, the higher the manufacturing cost. Since this is contrary to one of the objects of the present invention, the processing temperature in the present invention is 1500 to 2200 ° C., which is an industrially feasible temperature, and the processing pressure is ^{1 to} 10 Torr (13.3 × 10 ^{1 to} 13 In the range of 3 × 10 ² Pa), a hydrocarbon gas having 1 to 8 carbon atoms is supplied at a flow rate of 5 to 50 l / min, and the holding time is adjusted to form a desired thickness. If this coating layer is too thick, it may peel off, and it may not be too thin in order to prevent the penetration of SiO gas into the interior, and at least a thickness of 10 to 100 μm in order to delay the reaction to turn into SiC, Furthermore, it is preferable that it is 20-80 micrometers.

また、表面の被覆層は、ＣＶＩ法によって、熱分解炭素で内部の気孔が埋められ、更には、炭素繊維によって形成されている表面の段差が埋められている。そのため、ＣＶＤ処理されることによって、表面に被覆される熱分解炭素の表面粗さを５μｍ以下、更には４μｍ以下とすることが可能となる。このため、表面の比表面積が小さくなり、ＳｉＣ化を抑制することが可能となる。   Further, the surface coating layer is filled with pyrolytic carbon by the CVI method, and further, the surface step formed by the carbon fiber is filled. Therefore, by performing the CVD process, the surface roughness of the pyrolytic carbon coated on the surface can be set to 5 μm or less, and further to 4 μm or less. For this reason, the specific surface area of a surface becomes small and it becomes possible to suppress SiC-ization.

これら含浸層、被覆層を形成する熱分解炭素は加熱方法、基材温度、ガス濃度、ガス種類、流速などの製造条件によって密度や形状が異なる。図１(Ｃｈｅｍｉｓｔｒｙａｎｄ Ｐｈｙｓｉｃｓ ｏｆ Ｃａｒｂｏｎ， Ｖｏｌ．５， Ｐ．４７) に例として、密度と熱分解炭素生成温度の関係を示す。図に示されているように、熱分解炭素の密度は低温域（８００〜１３００℃）では約２．２ｇ／ｃｍ^３であるが、１３００〜１７００℃の温度域では密度が減少し、１７００℃を越える温度域で密度は再び増加しはじめ、炭素の理想密度に近い約２．２ｇ／ｃｍ^３となる。これは、核析出速度と成長速度との相乗効果に因る。核析出速度、成長速度ともに、温度が高くなるにしたがい速くなる。従って、高温域では核の析出、基材への堆積とともに、核の成長、配向が行われ、結晶子が大きく、規則正しく配向し、高密度となる。一方、低温域では基材温度が核成長に充分な温度でないため、核が殆ど成長せず、気相中で析出した核が基材上に堆積し高密度となる。また、中温域では、基材上の核が充分に成長、配向する前に新しい核が析出し、そのうえに堆積していくため、密度の低下、再増加という現象が生じる。すなわち、熱分解炭素の生成機構において、低温域では、気相で生成した核の基材上への積層が支配的であるが、高温域では基材上に沈積している核の成長、配向が支配的となる。 The pyrolytic carbon that forms the impregnation layer and the coating layer varies in density and shape depending on manufacturing conditions such as heating method, substrate temperature, gas concentration, gas type, and flow rate. As an example, FIG. 1 (Chemistry and Physics of Carbon, Vol. 5, P. 47) shows the relationship between density and pyrolytic carbon production temperature. As shown in the figure, the density of pyrolytic carbon is about 2.2 g / cm ³ in the low temperature range (800-1300 ° C.), but the density decreases in the temperature range of 1300-1700 ° C. The density begins to increase again in the temperature range exceeding ^1, and becomes about 2.2 g / cm ³ which is close to the ideal density of carbon. This is due to the synergistic effect of the nucleation rate and the growth rate. Both the nucleation rate and the growth rate increase as the temperature increases. Therefore, in the high temperature region, the nucleus is grown and oriented along with the precipitation of the nucleus and the deposition on the base material, and the crystallites are large, regularly oriented, and high density. On the other hand, since the substrate temperature is not sufficient for the nucleus growth in the low temperature region, the nuclei hardly grow, and the nuclei precipitated in the gas phase are deposited on the substrate and become high density. Further, in the middle temperature range, new nuclei are deposited before the nuclei on the base material are sufficiently grown and oriented, and are deposited on the nuclei, thereby causing a phenomenon of density reduction and re-increase. That is, in the generation mechanism of pyrolytic carbon, the deposition of nuclei generated in the gas phase on the base material is dominant in the low temperature range, but the growth and orientation of nuclei deposited on the base material in the high temperature range. Becomes dominant.

本発明では、低温で生成する結晶子の細かい高密度熱分解炭素を含浸し、その上に連続的に高温で生成する結晶子の大きな高密度熱分解炭素を被覆する。この際に両者の密度をほぼ同じにすることにより、被覆層の耐剥離性を向上させる。ここで、密度をそろえるのは被覆処理時の炉内のガス濃度を調節することにより行う。すなわち、炉内温度、ガス流量、処理圧力等を調節する。   In the present invention, fine high-density pyrolytic carbon of crystallites generated at a low temperature is impregnated, and large high-density pyrolytic carbon of crystallites generated continuously at a high temperature is coated thereon. At this time, the peel resistance of the coating layer is improved by making the densities of the both substantially the same. Here, the density is adjusted by adjusting the gas concentration in the furnace during the coating process. That is, the furnace temperature, gas flow rate, processing pressure, etc. are adjusted.

またＣＶＩ、ＣＶＤ処理を分けて行うと両者により生成された熱分解炭素層間の境界が明確に現れる場合などがある。例えば、各処理時の条件を前記の熱分解炭素の生成機構を考慮せずに行った場合や、炉から一旦出し、外気に晒したあと、再度ＣＶＤ炉内に設置しＣＶＤ処理を行った場合等である。ＣＶＩ処理終了後、一旦炉外に出してしまうと、外気中の不純物がその表面に吸着し、ＣＶＤ処理時の加熱中に表面に残った不純物により、ＣＶＤ処理時に核が異常成長を起こし、規則正しく配向しない等、核の成長が阻害される結果等が起こりうる。これらが、形成される含浸層、被覆層の境界が明確に現れる原因の一つと考えられる。このような境界が形成された場合、表面にＣＶＤ法により形成された被覆層は熱衝撃等により、容易に層の剥離や割れが起こる。そのため、含浸層、被覆層の両者を形成してもその効果が半減される。   In addition, when the CVI and CVD processes are performed separately, the boundary between pyrolytic carbon layers generated by both may appear clearly. For example, when the conditions at the time of each treatment are performed without considering the above-mentioned pyrolytic carbon generation mechanism, or when the CVD treatment is performed again after being taken out of the furnace and exposed to the outside air in the CVD furnace Etc. Once exited from the furnace after the CVI process is completed, impurities in the outside air are adsorbed on the surface, and the nuclei grow abnormally during the CVD process due to impurities remaining on the surface during heating during the CVD process. For example, the orientation of the nucleus may be hindered, such as not being oriented. These are considered to be one of the causes that the boundary between the impregnated layer and the coating layer to be formed clearly appears. When such a boundary is formed, the coating layer formed on the surface by the CVD method easily peels off or cracks due to thermal shock or the like. Therefore, even if both the impregnation layer and the coating layer are formed, the effect is halved.

従って、含浸層、被覆層の両層の組織を揃え、密度差を０．２ｇ／ｃｍ^３以内とし、境界を明確にしないで連続的な層を形成し、ＣＶＩ、ＣＶＤ法の両者の特徴を兼備した特性を有するには、同一炉内で連続的に且つ処理条件を調節し、含浸、被覆処理を行うことが好ましい。これにより、ＣＶＩ法によって形成された含浸層の最外核の熱分解炭素が、不純物に阻害されることなく、ＣＶＤ処理時の核となり、あらたに被覆層を形成していくことが可能であると考えられる。 Therefore, the structures of both the impregnation layer and the coating layer are aligned, the density difference is within 0.2 g / cm ^3, and a continuous layer is formed without clarifying the boundary. In order to have the combined characteristics, it is preferable to perform the impregnation and coating treatment continuously in the same furnace while adjusting the treatment conditions. Thereby, the pyrolytic carbon of the outermost core of the impregnated layer formed by the CVI method becomes a nucleus during the CVD process without being inhibited by impurities, and it is possible to form a new coating layer. it is conceivable that.

また、連続的にＣＶＩ、ＣＶＤ処理を行うため、従来よりも、含浸層、被覆層の厚みを厚く取ることが可能となる。剥離が発生しにくくなるからである。また、Ｃ／Ｃ材の表面粗さは、Ｃ／Ｃ材を形成する繊維の種類や、形成方法に依存するが、ＣＶＩ、ＣＶＤ処理によって、その表面粗さを制御することができる。そして、表面粗さを５μｍ以下とすることにより、表面の比表面積を小さくすることとなり、即ち、表面の外気との接触面積が小さくなり、耐ＳｉＣ化特性も改善できる。更に、連続的にＣＶＩ、ＣＶＤ処理を行うことにより、工程の簡略化、品質の安定化を計ることができ、優れた耐ＳｉＣ化を有するＣ／Ｃ材で形成された単結晶引き上げ装置用高温部材を提供することができる。   In addition, since the CVI and CVD processes are continuously performed, it is possible to make the impregnation layer and the coating layer thicker than before. This is because peeling is less likely to occur. The surface roughness of the C / C material depends on the type of fiber forming the C / C material and the forming method, but the surface roughness can be controlled by CVI or CVD treatment. When the surface roughness is 5 μm or less, the specific surface area of the surface is reduced, that is, the surface contact area with the outside air is reduced, and the SiC resistance characteristics can be improved. Furthermore, by performing CVI and CVD processes continuously, the process can be simplified and the quality can be stabilized, and the high temperature for a single crystal pulling apparatus formed of a C / C material having excellent SiC resistance. A member can be provided.

以下に、実施例を挙げ、本発明を具体的に説明する。
（実施例１）
炭素繊維シート（東レ製、６Ｋ平織り）にフェノール樹脂を含浸させ、前記炭素繊維シートを積層し、つぎに、２００度のオーブン中で１０時間熱処理し、樹脂の硬化を行った。次に電気炉にて、窒素雰囲気中で１０００℃で焼成を行った。更に緻密化のためにピッチ含浸−焼成を３回繰り返した。その後２０００℃の熱処理を行った後、６０×１０×３（ｍｍ）の形状に加工し、２０００℃でハロゲンガスと反応させることにより、高純度化処理を行った。ついで、１１００℃、１０Ｔｏｒｒ（１３．３×１０^２Ｐａ)下でＣＨ_４ガスを流量１０ｌ／ｍｉｎで供給し、１００時間保持するＣＶＩ 処理を施すことにより、熱分解炭素の含浸を行った。ＣＶＩ 処理後、更に引き続き、同一炉内で連続的に２０００℃まで加熱し、５Ｔｏｒｒ（６．６７×１０^２Ｐａ)に減圧するとともに、ＣＨ_４ガスを流量５ｌ／ｍｉｎで供給し、３時間保持するＣＶＤ処理により平均面粗さ１．９μｍ、厚さ５０μｍの熱分解炭素層を形成させ、試験用試料を得た。 Hereinafter, the present invention will be specifically described with reference to examples.
Example 1
A carbon fiber sheet (Toray, 6K plain weave) was impregnated with a phenol resin, the carbon fiber sheet was laminated, and then heat-treated in a 200 ° C. oven for 10 hours to cure the resin. Next, baking was performed at 1000 ° C. in a nitrogen atmosphere in an electric furnace. Further, pitch impregnation-firing was repeated three times for densification. Thereafter, a heat treatment at 2000 ° C. was performed, and then a shape of 60 × 10 × 3 (mm) was processed, and a high purity treatment was performed by reacting with a halogen gas at 2000 ° C. Next, impregnation with pyrolytic carbon was carried out by supplying a CH ₄ gas at a flow rate of 10 l / min at 1100 ° C. and 10 Torr (13.3 × 10 ² Pa) and holding it for 100 hours. After the CVI treatment, it is continuously heated to 2000 ° C. in the same furnace, the pressure is reduced to 5 Torr (6.67 × 10 ² Pa), and CH ₄ gas is supplied at a flow rate of 5 l / min and held for 3 hours. A thermal decomposition carbon layer having an average surface roughness of 1.9 μm and a thickness of 50 μm was formed by the CVD process to obtain a test sample.

（実施例２）
前記実施例１と同様にして作製した同形状のＣ／Ｃ材を、実施例１と同一条件で高純度処理、含浸処理を行った。その後、実施例１と同様にＣＶＩ処理後、連続的に同一炉で１８００℃、５Ｔｏｒｒ（６．６７×１０^２Ｐａ)、ＣＨ_４ガス流量５ｌ／ｍｉｎの条件で３時間保持するＣＶＤ処理により平均面粗さ２．０μｍ、厚さ約５０μｍの熱分解炭素層を形成させ、試験用試料を得た。 (Example 2)
A C / C material having the same shape produced in the same manner as in Example 1 was subjected to high-purity treatment and impregnation treatment under the same conditions as in Example 1. Then, after the CVI treatment in the same manner as in Example 1, the average was continuously obtained by the CVD treatment that was held in the same furnace for 3 hours at 1800 ° C., 5 Torr (6.67 × 10 ² Pa), and CH ₄ gas flow rate of 5 l / min. A pyrolytic carbon layer having a surface roughness of 2.0 μm and a thickness of about 50 μm was formed to obtain a test sample.

（実施例３）
マンドレル表面にＰＡＮ系炭素繊維の平織りクロス（トレカＴ−３００ ６Ｋ 東レ（株）製）にフェノール樹脂を含浸したものを１ 層張りつけ、その上にフィラメントワインディングを施した。フィラメントワインディングは、トレカＴ−３００ １２Ｋ （東レ（株）製）フィラメント６本にフェノール樹脂を含浸させながら、レベル巻き、中心軸に対する巻き付け角が８５°〜９０°のパラレル巻きを交互に５層ずつ巻き付けた。胴部はパラレル巻きとレベル巻きの１０層になるが、底部はレベル巻きだけになる。これにより層厚み１０mmの成形体が得られた。つぎに、オーブン中にて１００℃で揮発分調整を行ったのち、真空バッグを被せて真空引きをしながら、オーブンの温度を２００℃まで上げて成形体を熱硬化させた。熱硬化後、マンドレルから取り外し、成形体を得た。つぎに、胴部の真円度を保つために、黒鉛製の変形防止用治具を取付け、電気炉で窒素注入しながら１０℃／ｈｒの昇温速度で１０００℃まで昇温し、Ｃ／Ｃ材を得た。これを、ハロゲンガス雰囲気下で２０００℃に加熱し、１０時間保持し、高純度化処理を行った。さらに、ピッチ含浸を行い、電気炉で窒素注入しながら１０℃／ｈｒの昇温速度で１０００℃まで昇温し、焼成を行う。これを２回繰り返し、再度ハロゲンガス雰囲気の常圧下で２０００℃に加熱し、黒鉛化と共に高純度化処理を行った。その後、実施例１と同一条件でＣＶＩ処理を行い、ＣＶＩ処理後、連続的に同一炉で１８００℃、５Ｔｏｒｒ（６．６７×１０^２Ｐａ) 、ＣＨ_４ガス流量５ｌ／ｍｉｎの条件で３時間保持するＣＶＤ処理により平均面粗さ５．０μｍ、厚さ約５０μｍの熱分解炭素層を形成させ、試験用試料を得た。 (Example 3)
One layer of a PAN-based carbon fiber plain weave cloth (Torayca T-300 6K manufactured by Toray Industries, Inc.) impregnated with a phenol resin was applied to the mandrel surface, and filament winding was performed thereon. Filament winding consists of 5 layers of TORAYCA T-300 12K (manufactured by Toray Industries, Inc.) with 6 filaments impregnated with phenolic resin, level winding and parallel winding with a winding angle of 85 ° to 90 ° with respect to the central axis I wrapped it. The body has 10 layers of parallel winding and level winding, but only the level winding at the bottom. As a result, a molded body having a layer thickness of 10 mm was obtained. Next, after adjusting the volatile content at 100 ° C. in an oven, the temperature of the oven was raised to 200 ° C. while evacuating the vacuum bag, and the molded body was thermally cured. After thermosetting, the molded body was removed from the mandrel. Next, in order to maintain the roundness of the body, a graphite deformation preventing jig is attached, and the temperature is raised to 1000 ° C. at a temperature rising rate of 10 ° C./hr while nitrogen is injected in an electric furnace. C material was obtained. This was heated to 2000 ° C. in a halogen gas atmosphere and held for 10 hours to perform a purification treatment. Further, pitch impregnation is performed, and the temperature is increased to 1000 ° C. at a temperature increase rate of 10 ° C./hr while nitrogen is injected in an electric furnace to perform firing. This was repeated twice and again heated to 2000 ° C. under normal pressure in a halogen gas atmosphere, and subjected to graphitization and high purification treatment. Thereafter, CVI treatment was performed under the same conditions as in Example 1. After CVI treatment, continuously for 3 hours in the same furnace at 1800 ° C., 5 Torr (6.67 × 10 ² Pa), and CH ₄ gas flow rate of 5 l / min. A pyrolytic carbon layer having an average surface roughness of 5.0 μm and a thickness of about 50 μm was formed by the retained CVD process, and a test sample was obtained.

（比較例１）
前記実施例１と同様にして作製した同形状のＣ／Ｃ材に、実施例１と同一条件で高純度処理、含浸処理を行った。その後、ＣＶＩ処理を行わない以外、実施例１と同様に２０００℃で、５Ｔｏｒｒ（６．６７×１０^２Ｐａ)下で、ＣＨ_４ガスを流量５ｌ／ｍｉｎで供給し、３時間保持するＣＶＤ処理のみを行うことにより平均面粗さ５．０μｍ、厚さ１０μｍの熱分解炭素層を形成させ、試験用試料を得た。 (Comparative Example 1)
A high purity treatment and an impregnation treatment were performed on the C / C material having the same shape as in Example 1 under the same conditions as in Example 1. Thereafter, a CVD process in which CH ₄ gas is supplied at a flow rate of 5 l / min at 2000 ° C. and 5 Torr (6.67 × 10 ² Pa) as in Example 1 except that the CVI process is not performed. Was carried out to form a pyrolytic carbon layer having an average surface roughness of 5.0 μm and a thickness of 10 μm to obtain a test sample.

（比較例２）
前記実施例１と同様にして作製した同形状のＣ／Ｃ材に、実施例１と同一条件で高純度処理、含浸処理を行った。その後、実施例１と同様に１１００℃、１０Ｔｏｒｒ（１３．３×１０^２Ｐａ)下で、ＣＨ_４ガスを流量１０ｌ／ｍｉｎで供給し、１００時間保持し、熱分解炭素のＣＶＩ処理のみを行い、試験用試料を得た。表面の平均面粗さは７．０μｍであった。 (Comparative Example 2)
A high purity treatment and an impregnation treatment were performed on the C / C material having the same shape as in Example 1 under the same conditions as in Example 1. Thereafter, as in Example 1, CH ₄ gas was supplied at a flow rate of 10 l / min at 1100 ° C. and 10 Torr (13.3 × 10 ² Pa), held for 100 hours, and only CVI treatment of pyrolytic carbon was performed. A test sample was obtained. The average surface roughness of the surface was 7.0 μm.

（比較例３）
前記実施例１と同様にして作製した同形状のＣ／Ｃ材を、実施例１と同一条件で高純度処理、含浸処理を行い、ＣＶＩ、ＣＶＤ処理を施さず、試験用試料とした。 (Comparative Example 3)
A C / C material of the same shape produced in the same manner as in Example 1 was subjected to high-purity treatment and impregnation treatment under the same conditions as in Example 1, and was not subjected to CVI and CVD treatment, and was used as a test sample.

前記実施例１〜３と、比較例１〜３で得られた試料を、金属シリコンと一緒に真空炉内に設置し、１８００℃、１００Ｔｏｒｒ（１３．３×１０^３Ｐａ）、５時間の条件で反応性試験を行った。試験後、各試料の重量変化を測定しＳｉＣ化率すなわち、ＳｉＯガスとの反応率を調べた。 The samples obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were placed in a vacuum furnace together with metal silicon, and the conditions were 1800 ° C., 100 Torr (13.3 × 10 ³ Pa), 5 hours. A reactivity test was performed. After the test, the weight change of each sample was measured to examine the SiC conversion rate, that is, the reaction rate with SiO gas.

更に、前記実施例１〜３及び比較例１と２で得られた試料について急熱急冷試験を行った。すなわち５分間で１０００℃に昇温急熱した試料を水中に投じて急冷し熱分解炭素の剥離状況を調べた。試料数はそれぞれ５個である。   Further, the samples obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were subjected to a rapid heating and quenching test. That is, a sample heated and rapidly heated to 1000 ° C. in 5 minutes was poured into water and rapidly cooled to examine the state of peeling of pyrolytic carbon. The number of samples is 5 each.

前記ＳｉＣ化率、急熱急冷試験結果、ＣＶＩ、ＣＶＤ処理後の熱分解炭素の密度を表１にまとめる。ここで、熱分解炭素の密度はＸ線回折分析による炭素の［００２］面の回折強度比より配向度を求め算出した。   Table 1 summarizes the SiC conversion rate, rapid thermal quench test results, CVI, and the density of pyrolytic carbon after CVD treatment. Here, the density of pyrolytic carbon was calculated by obtaining the degree of orientation from the diffraction intensity ratio of the [002] plane of carbon by X-ray diffraction analysis.

表１からも分かるように、含浸層、被覆層の密度差が０．２ｇ／ｃｍ^３以内である実施例１〜３の試料は、耐剥離性、耐Ｓｉ性ともに優れていることがわかる。また、実施例３のようにフィラメントワインディング法により形成した試料は、表面の平均面粗さが実施例１及び２に比較すると少し悪くなり、それに伴い耐ＳｉＣ化率も少し悪くなっている。また、比較例１は、ＣＶＤでのみ表面に熱分解炭素を被覆しただけであるため、急熱急冷試験の結果、表面の被覆層が剥離した。比較例２の試料は、ＣＶＩ処理により熱分解炭素を含浸しただけであるため、耐ＳｉＣ化率が悪くなっている。 As can be seen from Table 1, it can be seen that the samples of Examples 1 to 3 in which the density difference between the impregnation layer and the coating layer is within 0.2 g / cm ³ are excellent in both peel resistance and Si resistance. Further, the average surface roughness of the sample formed by the filament winding method as in Example 3 is a little worse than that in Examples 1 and 2, and accordingly, the SiC resistance is slightly worse. Moreover, since the comparative example 1 only coat | covered the pyrolytic carbon on the surface only by CVD, the surface coating layer peeled as a result of the rapid thermal quenching test. Since the sample of Comparative Example 2 is only impregnated with pyrolytic carbon by CVI treatment, the SiC resistance rate is poor.

以上、本発明の好適な実施形態について説明したが、本発明は上述の実施の形態に限られるものではなく、特許請求の範囲に記載した限りにおいて様々な変更が可能なものである。   The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

Claims (4)

ピッチ及び／又は樹脂の含浸により緻密化した後、ＣＶＩにより熱分解炭素の含浸層を形成し、更に前記含浸層の上にＣＶＤにより熱分解炭素の被覆層を形成してなり、
前記被覆層の平均面粗さが５μｍ以下である炭素繊維強化炭素複合材。 After densification by pitch and / or resin impregnation, a pyrolytic carbon impregnation layer is formed by CVI, and a pyrolytic carbon coating layer is formed on the impregnation layer by CVD,
The carbon fiber reinforced carbon composite material whose average surface roughness of the said coating layer is 5 micrometers or less. 前記含浸層及び前記被覆層の密度差が０．２ｇ／ｃｍ^３以下である請求項１に記載の炭素繊維強化炭素複合材。 The carbon fiber reinforced carbon composite material according to claim 1, wherein a density difference between the impregnated layer and the coating layer is 0.2 g / cm ³ or less. 前記含浸層及び前記被覆層は、同一炉で連続的に形成された請求項１又は２に記載の炭素繊維強化炭素複合材。   The carbon fiber reinforced carbon composite material according to claim 1 or 2, wherein the impregnation layer and the coating layer are continuously formed in the same furnace. 請求項１〜３のいずれか１項に記載の炭素繊維強化炭素複合材により形成された単結晶引き上げ装置用部材。






The member for single crystal pulling apparatuses formed with the carbon fiber reinforced carbon composite material of any one of Claims 1-3.

Images