The Element Carbon 6 C 12.01 Diamond & Derivates Graphite & Derivates Fullerene & Nanotubes SGL Group 2007: Sales: 1373 mio. Employees: 5862 Net profit: 131 mio. R&D costs: 30 mio. Supplier (Gr. Powder...) Production R&D R&D 3
Graphite (Single Crystal) Structure & Properties - Overview - low strength (bonding energy 7 kj/mol) - low stiffness (36.5 GPa) - soft (mohs 0.5); good lubricant prop. - high thermal expansion (28.6 * 10-6 /K) - low thermal conductivity (< 8 W/(mK)) - high electrical resistivity (10 4 µωm) General Properties: - low weight (2.266 g/cm³) - high corrosion resistance - high temperature resistance - sensitive against oxidation 3.35 A Perpendicular to the carbon layers 1.41 A Parallel to the carbon layers - high strength (bond. energy 524 kj/mol) - high stiffness (~ 1060 GPa) - hard (mohs hardness 9) - low thermal expansion (-1.5 * 10-6 /K) - high thermal conductivity (> 1000 W/(mK)) - low electrical resistivity (0.5 µωm) 4
Carbon & Graphite History Major Milestones 1878 Swan/Edison: 1 st carbon fiber (cellulose) 1960s Natural Graphite 800 BC Ancient celts used graphite for fire resistant ceramics 1565 Lead pencil with natural graphite 1877 Refining of graphite ore was possible Invention of the flotation process 1891 Luzi: Expanded graphite 1991 Start asbestos ban (Germany) Carbon Fibers & Composites Shindo & Watt, Johnson, Bacon: PAN-based carbon fibers 1970/80s Start CFRC development 1980/90s Start C/SiC development ~ 2001 First serial C/SiC brake disc Polygranular Synthetic Graphite 1810 Davy: Carbon electrode for arc generation 1886 Hall & Heroult: Carbon electodes for Al-electrolysis 1893/94 Castner/Acheson: Graphitization processes 1942 Fermi: Nuclear reactor with graphite 1965 Brooks & Taylor: Carbon mesophase in pitch Fullerenes & Nanotubes 1985 Kroto, Curl & Smalley: Fullerenes 1990 Krätschmer et al.: Fullerene synthesis 1991 Iijima: Carbon nanotubes *) excluding milestones regarding diamond, carbon black, activated carbon, glassy carbon etc. 5
Expanded Graphite Based on Natural Graphite Main Production Steps natural graphite flakes (C-content: 98-99.98 %) intercalation solution (i.e.: H 2 SO 4 /HNO 3 ) formation of a graphite intercalation compound (i.e.: C 24 HSO 4 2.4 H 2 SO 4 ) thermal expansion at 1000 C (expanded graphite) removal of intercalated agents compacting the expanded graphite worms to graphite foil or sheets without any binder addition 8
Expanded Graphite Based on Natural Graphite Applications - Overview Increasing Density 0.002-0.02 g/cm³ 0.05-0.15 g/cm³ 0.1-0.4 g/cm³ 0.7-1.3 g/cm³ 1.5-1.9 g/cm³ Foil for Gaskets Bipolar Plates Thermal Conductive Matrix for PCM Battery Powder Base Material High Density Graphite Plates Graphite Foil Expanded Graphite Worms Exp. Graphite Powder Leight Weight Panels 9
Graphite Manufacturing Process Overview Raw material storage Coke, graphite, anthracite Pitch Weighting Mixing Crushing grinding Screening, sieving Extrusion vibromoulding isostatic pressing Baking (800 C) impregnation rebaking Storages for classified fractions + Machining (Purification & Coating) - Graphitisation (3000 C) 10
Polygranular Synthetic Carbon & Graphite Coarse - Fine Grain Applications - Overview Decreasing Grain Size 20000-1000 µm 1000-200 µm 20-15 µm 10 µm 3-1 µm Crucibles EDM Tools Nuclear Graphite Casting Dies Electrode/Nipple Vibration Moulded Graphite Coarse Grain Extruded Graphite 10 MPa Isostatic Graphite Increasing Bending Strength Super Fine Grain Fine Grain Isostatic Graphite Isostatic Graphite 100 MPa 11
Carbon Fiber Reinforced Carbon Manufacturing Process Raw Materials (C-fiber & resin) C-fiber Resin C-fiber + resin Lamination Filament Winding CFRP Pressing & Curing vacuum bag p vacuum Carbonisation Densification Rebaking Graphitization Machining gas vacuum CFRC 12
Carbon Fiber & Carbon Fiber Composites Value Chain - Overview Carbon fiber Textile products Prepreg CFRP CFRC C/SiC Carbon fibers Textile products Prepregs Carbon fiberreinforced Carbon fiberreinforced carbon (C/C) plastic (CFRP) Carbon fiberreinforced silicon carbide (C/SiC) 13
SGL GROUP THE CARBON COMPANY Best Solutions for our Customers Iron and Steel Non-Ferrous Metal Semiconductor High-performance graphite electrodes Carbon and graphite lining materials for blast furnaces Carbon and graphite cathodes in customized designs Fine-grain graphite for continuous casting High-purity fine-grain graphite for Si monocrystal-growing Coated graphite susceptors Best in Class Products, Services and Ideas to satisfy current and future Needs of our Customers 16
SGL GROUP THE CARBON COMPANY Best Solutions for our Customers Automotive Mechanical Engineering Chemicals Cylinder head gaskets Carbon ceramic brake discs Pump components made of carbon and graphite CFRP light weight components Fine-grain graphite for electrical discharge machining Sealing material Thermal decomposition units Multi-tube heat exchangers Best in Class Products, Services and Ideas to satisfy current and future Needs of our Customers 17
SGL GROUP THE CARBON COMPANY Best Solutions for our Customers Energy and Environmental Technology Aerospace High Temperature Technology Carbon fibers for wind power plants Cold storage systems for truck air conditioning High-purity fine-grain graphite for solar wafer production Primary structural CFRP components Carbon fibers for aircraft brakes SiC for satellite mirror support Graphite heaters and insulation material C/C charging systems Best in Class Products, Services and Ideas to satisfy current and future Needs of our Customers 18