EXPANDABLE GRAPHITE SHEET, METHOD FOR PROTECTING CARBONACEOUS CRUCIBLE USING THE EXPANDABLE GRAPHITE SHEET, AND SINGLE CRYSTAL PULLING APPARATUS

• Main Authors: HIROSE, YOSHIAKI, YUKI, TETSUYA
• Format: Patent
• Language: English; French; Japanese
• Published: 30.10.2008
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; COMPOUNDS THEREOF; CONCRETE; CRYSTAL GROWTH; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INORGANIC CHEMISTRY; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; LIME, MAGNESIA; METALLURGY; NON-METALLIC ELEMENTS; PERFORMING OPERATIONS; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; REFRACTORIES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; SLAG; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; TREATMENT OF NATURAL STONE; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

This invention provides an expandable graphite sheet having improved tensile strength. There are also provided a method for protecting a carbonaceous crucible, which can realize significant shortening of working time and, at the same time, can cover the internal surface of the crucible without any space and breaking of the sheet and is also suitable for increasing the size of the crucible, and a single crystal pulling apparatus, by using an expandable graphite sheet having improved tensile strength as an insole in a carbonaceous crucible. An expandable graphite sheet (10) is characterized in that a reinforcing material (12) formed of a carbon fiber is formed in a laminate form on at least one side of a base material (11) formed of an expandable graphite material. Further, it is characterized in that the expandable graphite sheet (10) is interposed between the quartz crucible and the carbonaceous crucible in which the quartz crucible is mounted, for use of the expandable graphite sheet (10) as an insole for covering the internal surface of the carbonaceous crucible. Cette invention concerne une feuille de graphite expansible présentant une résistance à la traction améliorée. Elle propose également un procédé pour protéger un creuset en matériau carboné, ledit procédé permet de réaliser une réduction significative du temps de travail et, simultanément, permet de couvrir la surface interne du creuset sans laisser aucun espace et sans casser la feuille, et convient également pour augmenter la taille du creuset. Enfin l'invention concerne un appareil pour tirage de monocristal. Le procédé consiste à utiliser une feuille de graphite expansible présentant une résistance à la traction améliorée comme semelle dans un creuset en matériau carboné. Une feuille de graphite expansible (10) est caractérisée en ce qu'un matériau de renforcement (12) à base de fibre de carbone est formé sous la forme d'un stratifié sur au moins une face d'un matériau de base (11) constitué d'un matériau de graphite expansible. En outre, le procédé se caractérise en ce que la feuille de graphite expansible (10) est interposée entre le creuset en quartz et le creuset en matériau carboné dans lequel le creuset en quartz est placé, en vue d'une utilisation de la feuille de graphite expansible (10) comme semelle pour couvrir la surface interne du creuset en matériau carboné.