Abrasive: A hard material used to
grind, cut or wear.
Absorption: The inclusion of the
energy of a photon within a substance.
Amorphous: A noncrystalline
substance, atoms lack long range order.
Annealing: Heat treatment to
Annealing point (glass):
Temperature at which stresses are removed.
Atomic vibration: Movement of an
atom within a substance.
Band gap energy: Energy
difference between the valence and conduction bands.
Brittle fracture: A break that
occurs by rapid crack propagation.
Capacitance (C): Charge storing
Cement: A material that binds
particles together in a mixture.
Ceramic: A compound of metallic
and nonmetallic elements.
Color: Wavelengths of light
perceived by the eye.
Component: A part, or device.
Conduction band: Carries the excited conduction electrons.
Conductivity: The ability to
carry an electric current (electricity) or thermal energy (heat).
Covalent bond: Bonding by sharing
Crystalline: A solid with a
repeating three-dimensional unit cell.
Crystal structure: The orderly
arrangement of the atoms or ions within a crystal.
Diamagnetism: Weakly repelled
from a magnetic field.
Dielectric: An insulator.
Dielectric constant: Relative
electrical permittivity of a material as compared to a perfect
Dielectric (breakdown) strength:
The amount of electricity needed to start an electric current flow
in a dielectric material.
Ductile fracture: Break
accompanied by large plastic deformation.
Elastic deformation: Change in
shape that returns when a stress is removed.
Elastic Modulus: Ratio of stress
to strain in elastic deformation, measure of elasticity.
Electric field: The gradient of
attraction of an atom for shared electrons.
Electron volt (eV): Unit of energy
equivalent to the energy gained by an electron when it falls
through an electric potential of one volt.
Excited state: An energy state to
which an electron may move by the absorption of energy.
Fiber Optics: The technology of
transferring information as light pulses through long thin fibers,
usually made of glass.
Firing: High temperature
processing to increase densification in a product.
Fluorescence: Light that is
emitted a short period of time after an electron has been
Fracture toughness (Kc): Measure
of a material's resistance to crack propagation.
Glass: An amorphous solid showing
characteristic specific volume behavior over a certain
Glass - ceramic: Crystalline
ceramic material that was formed by heat treating glass.
Glass transition temperature
(Tg): Temperature at which a glass changes from a
supercooled liquid into a solid.
Grain: Individual crystal in a
Grain boundary: The boundary
between grains (or crystals) that are misoriented with respect to
Green ceramic body: Ceramic
object that is dried but not fired.
Ground state: Lowest electron
Hardness: Resistance to
Heat capacity: Heat required to
produce a unit increase in temperature per quantity of
Imperfection: Flaw, any deviation
from perfection, as in a crystal.
Index of refraction: Ratio of the
speed of light in a vacuum to the speed of light in a medium.
Insulator: Material that does not
conduct electricity (electrical) or heat (thermal).
Ionic bond: Electrostatic force
between oppositely charged ions.
Laser: Source of coherent light
(Light Amplification by Stimulated Emission of Radiation).
Lattice: The regular arrangement
of points in a crystal.
Luminescence: Emission of visible
light when an electron returns to the ground state from an
Magnetic field strength:
Intensity of an applied magnetic field.
features that can be observed with a microscope.
Noncrystalline: Amorphous, with
no long-range atomic order.
Opaque: Material that does not
Phonon: Quantum of vibrational
that lasts for more than one second.
Photovoltaic cells: A device
capable of converting light energy to electricity.
conductivity induced by light.
Photon: Quantum of
Piezoelectric: Material that
produces an electrical response to a mechanical force.
Plastic deformation: Permanent
deformation, change of shape.
Polycrystalline: Composed of
more than one crystal or grain.
Porcelain: A durable ceramic
composite made by firing clay, feldspar and quartz together.
Reflection: Deflection of light
at the interface between two materials.
Refraction: Bending of light as
it passes from one medium into another.
Refractory: Material that can be
exposed to high temperature without deterioration.
Resistivity: Measure of
resistance to passage of electrical current (reciprocal of
material that has a relatively narrow energy band gap.
Sintering: Coalescence of
individual ceramic particles into a continuous solid phase at a
Slip: Mixture of clay with water
that can be poured into a mold.
Slip casting: Method of making
ceramic objects by pouring slip into a mold.
Softening point (glass): Maximum
temperature a glass can be heated before it permanently deforms.
Smart materials: Materials able
to detect a change in the environment and react to it.
Specific volume: Volume per unit
mass, reciprocal of density.
Strain: Change in length of a
sample in the direction of an applied stress.
Stress: Force applied to a
sample divided by its cross-sectional area.
Structural clay products: Ceramic
objects made mainly of clay and used in structural
Structure: Arrangement of
Disappearance of electrical resistivity at low temperatures.
Supercooling: Cooling below
the normal temperature for a phase change, without the change
Tensile strength: Maximum stress
Thermal expansion coefficient,
linear: Fractional change in length divided by change in
temperature, a measure of a materials tendency to expand when
Thermal stress: Residual stress
caused by a change in temperature.
Thermal tempering: The
introduction of residual compressive stresses to increase the
strength of glass.
Toughness: Energy absorbed by
a material as it fractures, a measure of its resistance to
Fracture by crack propagation through the grains.
Translucent: Transmits light
Transparent: Transmits light
Unit cell: The basic repeating
unit in a crystal.
Whiteware: Clay-based ceramic
that turns white after firing.