Silicon Carbide and Silicon Carbide Ceramics Specifications

Help with Silicon Carbide and Silicon Carbide Ceramics specifications:

Shape / Form

	Shape / Form:
	Your choices are...
	Bar Stock		Stock products are available in the form of a bar or rod, usually with a square cross-section. Stock forms can be processed in rectangular, oval, hexagonal, or other shapes.
	Fabricated / Custom Shape		Materials are fabricated in the form of a custom or application-specific shape such as a crucible, valve seat, blade, fired custom shaped brick or block, custom contoured tile, diffuser, furnace lining, degasser, and precast cement or concrete structural shape. The custom shape could be fabricated using pressing, slip casting, firing or sintering, melting, casting, cement form casting, and/or other processing methods.
	Ferrule / Eyelet		Ferrules and eyelets are cylindrically-shaped ceramic components with a central bore for protection or spacing applications. Refractory ferrules provide the best protection possible for vulnerable boiler tube inlet areas and metal tube sheets in sulfur recovery units (SRUs), methane reformers and waste heat boilers (WHBs). Eyelets are used in textile and wear guide applications.  Ceramic ferrules or stand-offs are used in circuit board, fiber optic, and RF & microwave applications. Electronic ferrules or stand-offs required good dielectric properties.  Optical ceramic ferrules are used in the alignment of optical fiber. Electronic ferrules are used in spacing or insulating electronic components.
	Plate / Board (e.g., Fiberboard)		Stock products are available in the form of a solid plate, slab, board, or substrate. The board or plate may consist of a ceramic fiberboard product, a dense sintered ceramic plate, or a precast cement bonded slab.
	Powder / Aggregate (Grain / Grog)		Stock products are available in a particulate form such as a powder, grog, grain, or fused and crushed aggregate.
	Precursor / Sol-gel		Stock or standard products are available in the form of a liquid, solid or gaseous chemical precursor, or sol-gel chemical components. Sol-gel ceramics are made using alkoxide precursor chemicals.
	Rod Stock		Stock products are available in the form of a rod or a bar with a round cross-section.
	Roller / Roll		Rolls or rollers are tube or hollow shaped components used in bearing, rolling, and material handling applications.  Ceramic rollers are a key component in hybrid ceramic roller bearings.  Ceramic or fused silica rolls are used in furnaces to handle or move hot glass sheet or other thermally processed materials.
	Filter / Diffuser		Spargers or diffusers are porous ceramics used to blow fine bubbles of a gas into a metal melt to remove impurities, particulates or other detrimental melt gases, de-oxidize melts, and enable chemical reactions. Filters are porous ceramics are used to remove impurities by passing the molten materials through the filter.
	Foundry / Plunger Tools (Stirrer, Stopper, etc.)		Foundry or plunger tools are designed to be immersed in molten metal and aid in the processing and casting of metal melts. Foundry and plunger tools include stirring rods, mixing paddles, dippers, skimmers, degasser tubes, degassing rotors, riser stalks, and stopper rods. Plunger mixers or stirring rods are dipped into molten materials to agitate, mix, or sample the metal or glass melt to assure consistent homogeneity. Stopper rods are used to control the flow and mixing of molten material in a crucible, ladle, pot or furnace. Stoppers are used to stop or control flow of a melt by plugging up a hole in the bottom of furnace crucible or melting pot. Dippers or skimmers are used to remove.
	Granular Fill / Bed Media		Granular fill is a loose, insulating material such as vermiculite that is loaded into a cavity to provide insulation and remains in a loose, unbonded condition. Bed media is a loose granular ceramic used in a catalytic oxidizer, fluid bed heater, or other thermal process unit to hold, filter or carry catalyst chemicals or particles during the heating, burning, or chemical reaction operation. Typically, ceramic bed media and granular fill have a high degree of porosity.
	Tube / Sheath - Immersion (Closed End)		Sheathed, immersion, or closed-end tubes are designed to protect heating elements, burners, or other devices in high-temperature furnaces from immersion in molten metals, glasses, or other melted materials.
	Wafer Carrier / Holder		Wafer carriers and holders are specialized devices for processing of silicon or compound (GaAs) semiconductor wafers. Ceramics are used to fabricate wafer carriers due to their corrosion resistance and refractoriness. Wafers are mounted onto or held by the carriers during dicing, polishing, lapping, thinning, chemical mechanical planarization (CMP), inspection or other operations.
	Wafer / Substrate		Ceramic products in the form of thin substrates and wafers are used in semiconductor, thin and thick-film deposition, and optoelectronics applications. The ceramic material may be a dielectric insulator, a semiconductor, or a semi-insulator. Wafers for semiconductor applications usually consist of round substrates that are precision-polished and planarized.
	Spout /  Nozzle (Launder Pouring / Atomization)		Pouring nozzles or orifices are used to direct or meter the flow of molten metal or other melted materials. Atomization nozzles are a critical component in the gas atomization process used to product metal powders. Ceramic nozzles are also used to shield other components of a system from arcs or abrasive jet/blast streams. Pouring cups, pouring tubes, tundish nozzles, and continuous casting tips also fit into this category.  A launder or spout is used delivery molten metal or molten glass from a furnace to ladle or crucible, from furnace to furnace, or from a furnace or crucible to a mold or forming equipment.
	Tile		Tile consists of a flat, thin ceramic shape usually with beveled edges for lining or covering a surface. Tile may have square, rectangular, hexagonal, triangular, round or custom shapes.  Tiles often have a protective glaze to create a waterproof or water resistance surface.  Tile can be smooth and glossy for wall applications, or anti-slip textured with a matt finish for floor applications.
	Tube Stock		Tube stock has a single, central bore or inner diameter. Tubes are commonly used as heating elements, for thermocouple protection, or channeling molten metal.
	Liner - Modular / Sectional		Modular or sectional lining systems consist of a series of interlocking components that fit or stack together to form a protective furnace lining. Induction furnaces often utilize a modular furnace lining system fabricated from ceramics that do not interfere with the inductive heating process. Liners may use a backup of ramming cement behind the liner, but not within the interlocking grooves.  Removal of refractory cement between the ceramic sections improves lining life and quality of the melt.  Tongue and groove crucibles are a modular crucible system consisting of a series of interlocking components that stack together to form a furnace lining or crucible.
	Kiln Furniture / Support		Beams, posts, setters, supports, rollers, baffles, kiln cars, boats, shelves, or other components are used to support, move, and process products or raw materials in furnaces or kilns.
	Block		Blocks are building materials or masonry units consisting of fired ceramic or cement materials with a regular shape. Blocks usually have a rectangular shape, although specialized shapes are used for paving, refractory, decorative and other specialized applications. Refractory or fireclay blocks are manufactured from temperature resistant materials.  Refractory blocks are stacked to form an insulating furnace, boiler, or other thermal process vessel wall.  The refractory blocks are usually cemented together with a refractory mortar. Blocks are similar to bricks but typically smaller in overall dimensions.
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	Hollow Stock / Shape?		Materials are supplied or available as hollow tubes, pipes or other stock with an open internal bore.
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Dimensions

	Length		The length of a stock material such as a bar, rod, plate or tube.
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	Width / O.D.		The width is the outer diameter (O.D.) of stock shapes such as bars, plates, and tubes; or of fabricated components such as crucibles.
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	Thickness / Wall Thickness		The thickness of a stock form, tube wall, or other fabricated component. Stock forms include bars, rods, plates and tubes.
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	Bore Diameter (I.D.)		The bore diameter or inner diameter (ID) is the width at the bottom of fabricated, tapered components such as crucibles.
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Thermal

	Max Use / Curie Temperature		This is the maximum temperature that the refractory or ceramic material can be exposed to momentarily without the degradation of structural or other required end-use properties.  The maximum use temperature is usually equal to the melt temperature of the metal, glass, or other material contained by the refractory body in the furnace, boiler or process unit. The Curie point is the temperature above which a material loses its unique magnetic, dielectric or piezoelectric property.  Ferrites or other magnetic materials lose their unique magnetic properties above the Curie temperature. The relative permeability drops to a value below 0.1 above the Curie temperature.  Magnetic susceptibility is inversely proportional to temperature.
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	Thermal Conductivity		Thermal conductivity is the linear heat transfer per unit area through a material for a given applied temperature gradient. Heat flux (h) = [thermal conductivity (k) ] x [temperature gradient (Δ T)]
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	Coeff. of Thermal Expansion (CTE)		The coefficient of linear expansion (CTE) is the amount of linear expansion or shrinkage that occurs in a material with a change in temperature.
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Electrical

	Dielectric Strength		Dielectric strength is the maximum voltage field that the ceramic or material can withstand before electrical breakdown occurs.
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	Dielectric Constant (Relative Permittivity)		The dielectric constant is the relative permittivity of a material compared to a vacuum or free space.  k = εr = ε / εo= where ε is the absolute permittivity of the material and εo is the absolute permittivity of a vacuum 8.85 x 10-12 F/m.
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	Loss Tangent (tan δ )		In dielectric materials, the loss tangent or loss coefficient is ratio of the imaginary or loss permittivity to the real permittivity of a material. In a capacitive circuit with a sinusoidal or AC voltage, the loss tangent is equal to the ratio of dissipated or discharged current to the storage current tan δ = | IR / IC | .  The dielectric quality factor (Q) is equal the inverse of the loss tangent. High Q or low loss tangents are required to reduce insertion losses.  Q = (average stored energy per cycle / energy dissipated per cycle) In magnetic materials or ferrites, the loss tangent or loss coefficient is ration of complex imaginary permeability (µ") to real permeability(µ').
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	Electrical Resistivity		Electrical resistivity is the longitudinal electrical resistance (ohm-cm) of a uniform rod of unit length and unit cross-sectional area. Electrical resistivity is the inverse of conductivity. High resistivity is a defining characteristic of a dielectric material.
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Mechanical

	MOR / Flexural Strength		Modulus of rupture (MOR), cross-break strength or flexural strength (3-point or 4-point) is the maximum flexural stress a bar can withstand before failure or fracture occurs. The bar is supported by two points beneath the bar and the load is applied by one or two points above the bar. Cross break strength is used to evaluate the strength of ceramics or other materials that do not provide sufficient plastic deformation to test tensile strength reliably.
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	Compressive / Crushing Strength		The crushing or compressive strength is the maximum compressive load per unit cross section that a ceramic body can withstand before mechanical failure or breakage occurs.
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	Modulus of Elasticity		Young's modulus or the modulus of elasticity is a material constant that indicates the variation is strain produced under an applied tensile load.  Higher modulus of elasticity materials provides higher stiffness or rigidity.
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Physical & Optical Properties

	Density		Density is the mass per unit area for a material.  The fired density is dependent on the theoretical density of 100% dense body and the actual porosity retained after processing.
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	Index of Refraction		The index of refraction is a measure of the speed of light in a material.
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	Transmission		This is the amount of light transmitted through a material.
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Applications

	Applications:
	Your choices are...
	Abrasive / Erosive Wear Protection		Materials resist damage by abrasion or erosion, and protect underlying surfaces from abrasive or erosive wear.
	Armor / Ballistic Protection		Materials are used to protect equipment, vehicles and/or personal against damage from blasts, explosions, bullets and other high-speed projectiles.
	Battery / Fuel Cell		Material is suitable for use in battery or fuel cell as a collector plate, proton exchange membrane or catalyst.
	Biocompatible / Bioceramics		Bioceramics are specially formulated or designed to have suitable biocompatibility for biotechnology and medical applications.
	Ceramics / Glass Manufacturing		Materials provide resistance to molten glass, or are compatible with ceramics and glasses during firing, calcining or fusing in a kiln or furnace.
	Chemical / Materials Processing		Materials provide high temperature and/or corrosion resistance, making them suitable for chemical-processing applications.  Examples include ceramics or refractories with resistance to molten glass, ceramics, metals, plastics or other materials during milling, firing, calcination, fusion or other processes.
	Construction & Building / Architectural		Materials are designed or suitable for use in architectural, building, and construction applications. Examples include bricks, fire bricks or tiles.
	Optics / Optical Grade		Ceramic, optical grade materials are used in the fabricating or processing of optical components such as lenses, windows, prisms, optical fibers, and lasing material components. Materials with optical applications include single-crystal ceramics, transparent ceramics, sapphire, and quartz.
	Refractory / High Temperature Materials		Refractory and high-temperature materials are hard, heat-resistant products such as alumina cement, fire clay, bricks, precast shapes, cement or monolithics, and ceramic kiln furniture. Ceramic refractories have high melting points and are suitable for applications requiring wear-resistance, high temperature strength, electrical or thermal insulation, or other specialized characteristics.
	Thermal Insulation / Fire Proofing		Thermally-insulating ceramics and refractories provide a thermal barrier between components and a hot or cold source. These ceramics and refractory shapes are also useful in providing flame protection and fire-proofing between a burner and the surrounding environment, or between combustion and oxygen sources.
	Corrosion Protection		Materials are designed or suitable for corrosive environments, such as the floors or walls of chemical processing plants.
	Electrical / HV Parts		Materials are used to fabricate electrical parts for high voltage or power applications. Examples include insulators, igniters or heating elements.
	Electronics / RF-Microwave		Materials are suitable for electronics applications, including RF and microwave. Ferrites, garnets, alumina/sapphire and silicates have sufficient dielectric properties for use in electronic, radio frequency (RF) and microwave devices such as antenna radomes, patch antenna substrates, thin/thick film substrates and resonators. In addition, ceramics, glass and other non-metallic compounds or elemental semiconductors are used as substrates, wafer or dummy wafers in semiconductor manufacturing.  Ceramics are also used for wafer chucks or holders, wafer furnace boats and thin film chamber liners.
	Foundry / Metal Processing		Materials are designed for foundry and metal-processing applications. Ceramic and refractory crucibles, tubes, stoppers, liners, spouts, permanent molds, thermocouple protection tubes, combustion gas heater tubes, submersible heater tubes, die casting stalks/sleeves, and other furnace components are used in foundries for melting and casting aluminum, steel, copper alloys or other metals.
	Structural		Structural applications require ceramic components with a suitable strength, elastic modulus, toughness, and other mechanical properties. Ceramics can have much higher compressive strengths and elastic moduli compared to metals.
	Wear Parts / Tooling		Wear-resistant ceramics are used in industrial products such as automotive rings, pump parts, valve seals/seats, faucet discs, papermaking machine dewatering strips, aluminum can dies, wire drawing dies and textile guides.
	Other		Other unlisted, specialized or proprietary applications.
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Features

	Performance Features:
	Your choices are...
	Machinable		Machinable ceramics can be machined in the green, glass or finished state without excessive chipping. Typically, non-machinable ceramics are ground to finished dimensions, often with super abrasive grinding wheels.
	Metallized / Silvered (Electrode, Mirror)		Ceramic surfaces are coated with a thin metal layer applied by plating, thin film, fired-on coating or other process. The coatings maybe continuous or selectively patterned on the surface or thru vias. In addition, float glass sheet or glass plate silvered to produce sheet mirror stock.
	Modified / Doped		Materials are modified or doped with ions or additions of another ceramic to impart specific properties or improve processing.
	Porous / Foam		Porous ceramics have a large degree of open or closed internal pores that provide a thermal barrier.  Certain ceramics have intrinsically low thermal conductivity, even in dense forms.  Reticulated foam refractories are useful in filtering molten metals and providing an extremely low density structure for insulation or other applications.
	Specialty / Other		Other unlisted, specialized, or proprietary material features.
	Coated		Coated materials use or are available with a glaze (fused glass enamel), metallized coating, plastic coating or other protective coating. The coating may seal porosity, improve water or chemical resistance, or enhance joining to metals or other materials. This category also includes glass materials with an organic coating or film, or ceramic frit coating for spandrel applications.
	Composite / Ceramic Matrix		Composite materials consist of a matrix material reinforced with a stronger or higher modulus second phase.  The second phase may be in the form of particulates, chopped fibers or continuous fibers.  The matrix may consist of a ceramic in CRC or ceramic matrix composites.  Ceramic or reinforcing fibers are commonly chosen with high modulus and/or strength.
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