Materials Science Vocabulary Flashcards

This set of flashcards contains key vocabulary terms and their definitions related to materials science, focusing on composite materials, electrical properties, and mechanical behavior.

Ceramic Matrix Composite

A composite for which both matrix and dispersed phases are ceramic materials, normally added to improve fracture toughness.

Concrete Dispersed Phase

The discontinuous phase surrounded by the matrix phase in composites and two-phase alloys.

Fiber Reinforced Composite

A composite in which the dispersed phase is in the form of a fiber that has a large length-to-diameter ratio.

Large Particle Composite

A type of particle-reinforced composite where particle-matrix interactions cannot be treated on an atomic level.

Longitudinal Direction

The lengthwise dimension; for a rod or fiber, in the direction of the long axis.

Matrix Phase

The continuous phase in a composite or two-phase alloy microstructure that completely surrounds the dispersed phase.

Metal Matrix Composite

A composite where the matrix is made of metal, surrounding the dispersed phase.

Rule of Mixtures

A method stating that the properties of a multiphase alloy or composite material are a weighted average of the properties of individual constituents.

Specific Modulus

The ratio of elastic modulus to specific gravity for a material.

Specific Strength

The ratio of tensile strength to specific gravity for a material.

Transverse Direction

A direction that crosses (usually perpendicularly) the longitudinal direction.

Trifunctional Anode

A term used to describe an electrode involved in multiple reactions; often related to energy systems.

Energy Band Gap

The minimum energy required to excite an electron from the valence band to the conduction band in a material.

Cathode

The electrode in an electrochemical cell where a reduction reaction occurs, receiving electrons from an external circuit.

Corrosion

The deteriorative loss of a metal as a result of dissolution from environmental reactions.

Electrolyte

A solution through which an electric current may be carried by the motion of ions.

Conduction Band

The lowest-lying electron energy band that is empty of electrons at 0 K for electrical insulators and semiconductors.

Doping

The intentional alloying of semiconducting materials with controlled concentrations of donor or acceptor impurities.

Electrical Conductivity

A measure of a material's ability to conduct electric current.

Intrinsic Semiconductor

A semiconductor material whose electrical behavior is characteristic of the pure material.

Mobility

The proportionality constant between the carrier drift velocity and applied electric field; also a measure of charge carrier motion.

Valence Band

The electron energy band in solid materials that contains the valence electrons.

Heat Capacity

The quantity of heat required to produce a unit temperature rise per mole of material.

Linear Coefficient of Thermal Expansion

Material property describing how much a material changes in length for each degree of temperature change.

Specific Heat

The heat capacity per unit mass of material.

Thermal Conductivity

A measure of a material's ability to conduct heat, relating heat flux to temperature gradient.

Thermal Shock

The fracture of a brittle material due to stresses introduced by a rapid temperature change.

Ductility

A measure of a material's ability to undergo plastic deformation before fracture.

Elastic Deformation

Nonpermanent deformation that is fully recovered after the stress is released.

Hardness

The resistance of a material to deformation, particularly permanent deformation.

Continuous-Cooling Transformation Diagram

A plot indicating when transformations occur as a steel alloy is continuously cooled.

Poisson’s Ratio

The ratio of transverse strain to longitudinal strain in the direction of stretching.

Martensite

A metastable iron phase supersaturated in carbon, produced from athermal transformation from austenite.

Spheroidite

A microstructure in steel alloys consisting of spherelike cementite particles in an alpha-ferrite matrix.

Modulus of Elasticity

The ratio of stress to strain in fully elastic deformation, measuring material stiffness.

Plastic Deformation

Permanent deformation that occurs when the material is subjected to a load beyond its yield strength.

Yield Strength

The stress required to produce a specified amount of plastic strain in a material.

Cold Working

Plastic deformation of a metal at a temperature below that of recrystallization.

Dislocation Density

The total length of dislocations per unit volume of material.

Slip System

The combination of a crystallographic plane and direction in which dislocation motion occurs.

Strain Hardening

Hardening and strengthening of metals from dislocation interactions due to plastic deformation.

Charpy Test

A test to measure impact energy or notch toughness of a standard notched specimen.

Fatigue Limit

The maximum stress a material can withstand for an infinite number of cycles without failing.