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Ceramic tube and ceramic rod products are used in high-temperature applications that require erosion resistance and electrical or thermal insulation. Like other ceramic products, ceramic tubes and rods consist of oxides, carbides, nitrides, carbon, and other non-metals with high melting points. These refractories are hard, heat-resistant materials and products such as alumina cement, fire clay, bricks, and precast shapes. Some examples of ceramic tube and ceramic rod products are precast tubes, ladle impact pads, damns and weirs, impact runners, troughs, covers, furnace roofs, and skimmer paddles.
Many different materials are used in ceramic tube and ceramic rod products. Alumina, a compound of aluminum metal and oxygen, is used in refractory tubes, industrial crucibles, analytical labware, dielectric substrates, wear components, refractory cements, and abrasives. Depending on its purity, density and crystal structure, carbon is used for refractory linings, industrial crucibles, arc furnace electrodes, analytical labware, composites, refractory cements and superabrasives. Ferrites, garnets, and ferromagnetic materials have dielectric and magnetic properties that are useful in RF, microwave, and specialized industrial applications. Sapphire ceramics are used in lasers, substrates, jewel bearings, watch crystals, and other specialized optical, wear, and electronic applications.
Ceramic tube and ceramic rod products are available with a variety of material features. Composite products have a reinforced matrix that includes metals, polymers, or glass fibers. Glazed products have a metallic coating or plastic seal to improve water or chemical resistance. Single-crystal ceramics do not contain any foreign materials, while sintered or fused products use only small traces of dopants or sintering aids. Porous and foam ceramics provide a thermal barrier and low electrical conductivity. Machinable ceramic tube and ceramic rod products can be machined in the green, glass, or finished state without excessive chipping. Typically, non-machinable ceramics are ground to finishing dimensions, often with superabrasive grinding wheels.
A variety of chemical and materials processing applications use ceramic tube and ceramic rod products. For example, ceramic tub and rod products are used to fabricate electrical parts for high voltage or power applications such as insulators, igniters or heating elements. Ceramics are also used in structural components, in foundries, and in semiconductors. Optical applications use single crystal ceramics, transparent ceramics, and ceramics that include sapphire and quartz.
Shapes and Types
Ceramic tube and ceramic rod products are available in a variety of shapes and types. Recuperator tubes are cross-shaped ceramic components that recover heat from combusted gases. Degassers are sometimes porous and bar stock usually has a square cross-section. Immersion tubes protect heating elements, burners, and other devices in high temperature furnaces from immersion in molten metal, glass, or other melted materials. Muffle or furnace tubes form a barrier between the heating elements and heated parts in a furnace. Runner or riser tubes distribute molten metal into the different regions of a mold or die at the proper times and flow rates. Stirring rods agitate melts to ensure a consistent homogeneity, while stopper rods plug the holes in the bottom of furnace crucibles and melting pots. Single, double, and multi-bore tubes have inner diameter openings and are commonly used for thermocouple electrical insulation and protection. Thermocouple tubes are designed to protect thermocouples from molten metals, glass, or materials.