(See related pages)
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| Ceramic materials | inorganic, nonmetallic materials that consist of metallic and nonmetallic elements bonded together primarily by ionic and/or covalent bonds. (See page(s) 592; Sec. 10.1) |
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| Coordination number (CN) | the number of equidistant nearest neighbors to an atom or ion in a unit cell of a crystal structure. For example, in NaCl, CN = 6 since six equidistant Cl- anions surround a central Na+ cation. (See page(s) 592; Sec. 10.2) |
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| Radius ratio (for an ionic solid) | the ratio of the radius of the central cation to that of the surrounding anions. (See page(s) 592; Sec. 10.1) |
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| Critical (minimum) radius ratio | the ratio of the central cation to that of the surrounding anions when all the surrounding anions just touch each other and the central cation. (See page(s) 592; Sec. 10.1) |
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| Octahedral interstitial site in the FCC crystal structure | the space enclosed when the nuclei of six surrounding atoms (ions) form an octahedron. (See page(s) 592; Sec. 10.1) |
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| Tetrahedral interstitial site in the FCC crystal structure | the space enclosed when the nuclei of four surrounding atoms (ions) form a tetrahedron. (See page(s) 592; Sec. 10.1) |
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| Dry pressing | the simultaneous uniaxial compaction and shaping of ceramic granular particles (and binder) in a die. (See page(s) 592; Sec. 10.4) |
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| Isostatic pressing | the simultaneous compaction and shaping of a ceramic powder (and binder) by pressure applied uniformly in all directions. (See page(s) 592; Sec. 10.4) |
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| Slip casting | a ceramic shape-forming process in which a suspension of ceramic particles and water are poured into a porous mold and then some of the water from the cast material diffuses into the mold, leaving a solid shape in the mold. Sometimes excess liquid within the cast solid is poured from the mold, leaving a cast shell. (See page(s) 592; Sec. 10.4) |
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| Sintering (of a ceramic material) | the process in which fine particles of a ceramic material become chemically bonded together at a temperature high enough for atomic diffusion to occur between the particles. (See page(s) 593; Sec. 10.4) |
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| Firing (of a ceramic material) | heating a ceramic material to a high enough temperature to cause a chemical bond to form between the particles. (See page(s) 593; Sec. 10.4) |
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| Vitrification | melting or formation of a glass; the vitrification process is used to produce a viscous liquid glass in a ceramic mixture upon firing. Upon cooling, the liquid phase solidifies and forms a vitreous or glassy matrix that bonds the unmelted particles of the ceramic material together. (See page(s) 593; Sec. 10.4) |
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| Dielectric | an electrical insulator material. (See page(s) 593; Sec. 10.6) |
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| Capacitor | an electric device consisting of conducting plates or foils separated by layers of dielectric material and capable of storing electric charge. (See page(s) 593; Sec. 10.6) |
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| Capacitance | a measure of the ability of a capacitor to store electric charge. Capacitance is measured in farads; the units commonly used in electrical circuitry are the picofarad (1 pF = 10-12 F) and the microfarad (1 μF = 10-6 F). (See page(s) 593; Sec. 10.6) |
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| Dielectric constant | the ratio of the capacitance of a capacitor using a material between the plates of a capacitor compared to that of the capacitor when there is a vacuum between the plates. (See page(s) 593; Sec. 10.6) |
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| Dielectric strength | the voltage per unit length (electric field) at which a dielectric material allows conduction, that is, the maximum electric field that a dielectric can withstand without electrical breakdown. (See page(s) 593; Sec. 10.6) |
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| Thermistor | a ceramic semiconductor device that changes in resistivity as the temperature changes and is used to measure and control temperature. (See page(s) 593; Sec. 10.6) |
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| Ferroelectric material | a material that can be polaized by applying an electric field. (See page(s) 593; Sec. 10.6) |
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| Polarization | the alignment of small electric dipoles in a dielectric material to produce a net dipole moment in the material. (See page(s) 593; Sec. 10.6) |
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| Curie temperature (of a ferroelectric material) | the temperature at which a ferroelectric material on cooling undergoes a crystal structure change that produces spontaneous polarization in the material. For example, the Curie temperature of BaTiO3 is 120oC. (See page(s) 593; Sec. 10.6) |
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| Piezoelectric effect | an electromechanical effect by which mechanical forces on a ferroelectric material can produce an electrical response and electrical forces produce a mechanical response. (See page(s) 593; Sec. 10.6) |
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| Transducer | a device that is actuated by power from one source and transmits power in another form to a second system. For example, a transducer can convert input sound energy into an output electrical response. (See page(s) 593; Sec. 10.6) |
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| Refractory (ceramic) material | a material that can withstand the action of a hot environment. (See page(s) 593; Sec. 10.8) |
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| Glass | a ceramic material that is made from inorganic materials at high temperatures and is distinguished from other ceramics in that its constituents are heated to fusion and then cooled to the rigid condition without crystallization. (See page(s) 593; Sec. 10.9) |
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| Glass transition temperature | the center of the temperature range in which a noncrystalline solid changes from being glass-brittle to being viscous. (See page(s) 593; Sec. 10.9) |
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| Glass-forming oxide | an oxide that forms a glass easily; also an oxide that contributes to the network of silica glass when added to it, such as B2O3 . (See page(s) 593; Sec. 10.9) |
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| Glass-modifying oxide | an oxide that breaks up the silica network when added to silica glass; modifiers lower the viscosity of silica glass and promote crystallization. Examples are Na2O, K2O, CaO, and MgO. (See page(s) 594; Sec. 10.9) |
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| Glass intermediate oxides | an oxide that may act either as a glass former or as a glass modifier, depending on the composition of the glass. Example, Al2O3 . (See page(s) 594; Sec. 10.9) |
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| Glass reference points (temperatures) | Working point: at this temperature the glass can easily be worked. Softening point: at this temperature the glass flows at an appreciable rate. Annealing point: at this temperature stresses in the glass can be relieved. Strain point: at this temperature the glass is rigid. (See page(s) 594; Sec. 10.9) |
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| Softening point | at this temperature the glass flows at an appreciable rate. (See page(s) 594; Sec. 10.9) |
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| Annealing point | at this temperature stresses in the glass can be relieved. (See page(s) 594; Sec. 10.9) |
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| Strain point | at this temperature the glass is rigid. (See page(s) 594; Sec. 10.9) |
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| Float glass | flat glass that is produced by having a ribbon of molten glass cool to the glass-brittle state while floating on the top of a flat bath of molten tin and under a reducing atmosphere. (See page(s) 594; Sec. 10.9) |
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| Thermally tempered glass | glass that has been reheated to near its softening temperature and then rapidly cooled in air to introduce compressive stresses near its surface. (See page(s) 594; Sec. 10.9) |
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| Chemically tempered glass | glass that has been given a chemical treatment to introduce large ions into its surface to cause compressive stresses at its surface. (See page(s) 594; Sec. 10.9) |