Materials Science and Engineering Terminology

A set of flashcards covering key terminology and concepts from materials science and engineering.

Incongruent

Melts into a liquid and different solid.

Steady-state diffusion

Diffusion that occurs at a constant rate.

Congruent

Liquid of same composition as solid.

Vacancy

Absence of an atom in a crystal structure.

Frenkel defect

A type of defect involving a vacancy and an interstitial in the same sublattice.

Schottky defect

Vacancies found in both sublattices of a crystal.

Twist boundaries

Boundaries characterized by a rotation image at the boundary.

Tilt boundaries

Boundaries that can be small or high angle orientation, relating to integer ratio of components.

Twin boundaries

Boundaries characterized by a mirror image at the boundary with an absence of an atom.

Interstitial

An extra atom situated in the crystal structure.

Inclusions

Embedded particles within a material.

SEM (Scanning Electron Microscope)

An instrument used to image the surfaces of materials and determine the type of dislocation.

TEM (Transmission Electron Microscope)

Used to image thin foils and examine materials.

XRD (X-ray Diffraction)

Technique used to determine crystal structures, involving rotation at boundary.

Fick's First Law

Describes steady-state diffusion.

Fick's Second Law

Describes time-dependent diffusion.

Substitutional impurity

An atom that replaces a host atom in a crystal structure.

Cracks

Defects that affect the time-dependent diffusion process.

Slip system

A system characterized by a line perpendicular to the Burgers vector.

Burgers vector

A vector that determines the type of dislocation in a crystal.

Edge dislocation

A type of dislocation where the line of dislocation is along the edge of the crystal.

Screw dislocation

A dislocation characterized by a spiral arrangement of atoms in the crystal.

Polymers

Materials that melt into a liquid and then form a different solid.

Glasses

Amorphous solids that experience vacancy and interstitial defects.

Liquidus

The temperature above which only liquid exists in a material.

Solidus

The temperature below which only solid exists in a material.

Intermediate Compound

A compound that exhibits short-range order only.

Nucleation

The process of forming a new phase within a material.

Recrystallization

A process performed to refine the grain size of metals.

Cold working

A strengthening mechanism involving deforming a material at lower temperatures.

Tempering

Re-heating process used to relieve stresses in a material.

Ferrite

A phase of iron (alpha-iron) in the crystal structure.

Austenite

A phase of iron (gamma-iron) that exists at higher temperatures.

Cementite

A compound of iron and carbon (Fe3C).

Pearlite

A mixture of ferrite and cementite.

Martensite

A hardened structure obtained from quenching steel.

Viscous deformation

Deformation behavior that is unique to amorphous materials.

Viscoelastic deformation

Deformation behavior that is unique to thermoplastic polymers.

Deformation by slip

The relationship between shear strain and shear stress.

Young's modulus

The slope of the stress versus strain curve for a material.

Poisson's ratio

The ratio of orthogonal strains in a material.