MS&E #12+13 Ceramics
34 flashcards · Physics · by Kristóf Nagy
Glass transition temperature
The temperature at which a glass transitions from a brittle, solid-like state to a leathery, rubbery state, characterized by a significant drop in viscosity.
Glass-ceramic
A composite material comprised of a glass matrix with embedded fine crystalline particles, formed through controlled crystallization of a parent glass.
Softening point (glass)
The temperature at which a glass transitions from a rigid, solid-like state to a soft, ductile state, characterized by a viscosity of 10^6.5 - 10^7.5 Pas (10^7.5 - 10^8.5 Poise).
Slip casting
A forming process in which a slurry (or slip) of ceramic particles suspended in water is poured into a porous plaster mold. Water gets absorbed by the mold, leaving behind a solid ceramic piece as it dries.
Calcination
A high-temperature heat treatment process used to convert raw materials into a "clinker" product, typically for cement production.
Sintering
A heat treatment process for consolidating and densifying powdered materials by promoting atomic diffusion and particle bonding at elevated temperatures.
Refractory (ceramic)
A high-temperature resistant ceramic material, typically used for linings, crucibles, or protective coatings in harsh environments.
Green ceramic body
An unfired, dried ceramic body, usually containing pores and exhibiting low strength.
Vitrification
Transformation of a material into a glassy state, characterized by the absence of long-range crystalline order. Occurs during sintering or firing of ceramic materials.
Firing
Heating a ceramic material to a high temperature to strengthen, harden, or vitrify it. Similar to sintering but generally refers to higher temperatures and longer duration.
Melting point (glass)
The temperature at which a glass transitions from a solid-like state to a liquid state, corresponding to a viscosity of 10^1 Pas (10^2 Poise).
Abrasive (ceramic)
A hard, tough ceramic material used to wear, grind, or cut away other materials. Examples include silicon carbide, tungsten carbide, and diamond.
Annealing point (glass)
The temperature at which the viscosity of a glass is 10^12 Pas (10^13 Poise), and atomic diffusion is sufficiently rapid to remove residual stresses within ~15 minutes.
Whiteware
A class of ceramic materials featuring high purity, whiteness, and translucency, typically used for decorative or artistic purposes. Includes porcelain, bone china, and fine china.
Cement
A binding agent that hardens due to a chemical reaction with water. Often refers specifically to portland cement, which is a hydraulic cement.
Hydroplastic forming
A forming process utilizing a wet, plastic mixture of clay and water. Can be performed through extrusion, injection molding, or slip casting.
Microelectromechanical system (MEMS)
Miniaturized electromechanical systems integrating mechanical and electrical components on a single chip, enabling sensing, actuation, and signal processing functions.
Crystallization (glass-ceramics)
The process of transforming a glass into a fine-grained polycrystalline material via a heat treatment, leading to improvements in mechanical properties and resistance to thermal shock.
Strain point (glass)
The temperature at which a glass exhibits a viscosity of 10^13.5 Pas (10^14.5 Poise), below which it will not deform plastically under its own weight.
Structural clay product
A category of clay-based ceramic materials intended for structural purposes, such as bricks, blocks, floor tiles, and sewer pipes.
Thermal shock
Rapid temperature fluctuations leading to mechanical stresses and potential cracking or failure in brittle materials like ceramics.
Thermal tempering
A heat treating process to create compressive surface stresses in glass, improving its resistance to thermal shock and increasing its overall strength.
Optical fiber
Ultra-pure glass fibers used to transmit light signals in communication networks, providing high bandwidth and low loss over long distances.
Frenkel defect
A defect structure characterized by the displacement of an atom from its original lattice site to an interstitial site.
Schottky defect
A defect structure characterized by the simultaneous creation of a cation vacancy and an anion vacancy.
stoichiometry
Exact ratio of constituent ions in a compound.
defect structure
The types and concentrations of atomic defects in ceramics.
electroneutrality
The state that exists when there are equal numbers of positive and negative charges from the ions.
anion
A negatively charged ion in a compound.
octahedral position
Position between closed-packed planes where six neighboring atoms form an octahedron around an atom.
cation
A positively charged ion in a compound.
viscosity
Resistance of a fluid to flow under an applied shear stress.
flexural strength
The maximum stress experienced in the outermost fibers of a beam subjected to bending.
tetrahedral position
Position between closed-packed planes where four neighboring atoms form a tetrahedron around an atom.