Fracture
A material failure mode in which the solid part is separated into two or more pieces due to an applied stress that is static and at low temperatures
Fatigue
A form/mode of material failure that occurs in materials subjected to dynamic and fluctuating stresses (cyclic stresses)
Endurance/Fatigue Limit
The stress below which fatigue will not occur
Fatigue Life
The number of cycles required to cause fatigue failure of the material when subjected to a specific stress level
Fracture Toughness (Kic)
A measure of the material's resistance to brittle fracture in the presence of a crack
Ductile Fracture
This occurs in ductile materials where a plastic deformation is developed in the material before the initiation of the crack
Brittle Fracture
It occurs in brittle materials where a very small or no plastic deformation occurs before the initiation of the crack
Creep
A mode of material failure that is time dependent and permanent deformation of the material when subjected to a constant load or stress
Solubility Limit
The maximation concentration of solute (impurity) atoms that may dissolve in the solvent (host substance) to form a solid solution at some specific temperature.
Phase Transformation
the change in the phase of the material upon altering (or changing) temperature or pressure
Isothermal Transformation
A phase transformation process in which the temperature of the alloy is held constant throughout the duration of the transformation
Equilibrium Cooling
a process in which the cooling of an alloy occurs very slowly wherein phase equilibrium is continuously maintained
Nonequilibrium Cooling
a process in which the cooling of an alloy occurs at rates higher than the diffusional rates required for the compositional readjustments of the alloy. Nonequilibrium cooling results in gradient compositions for one or more of the phases.
Pearlite
a lamellar structure consisting of alternating layers of alpha ferrite and cementite (Fe3C)
Bainite
a non-lamellar structure consisting of alpha ferrite matrix and elongated particles (needles) of cementite (Fe3C)
Spheroidite
is a microstructure of steel consisting of alpha ferrite matrix and spherical like particles of cementite (Fe3C)
Fatigue Strength
the stress level at which failure will occur for some specified number of cycles
Solvus Line
a line of the solid solubility limit, separating one solid phase from the solid mixture with another solid phase in a phase diagram
Solidus Line
the line that separates the solid phase from the solid-liquid mixture in a phase diagram
Liquidus Line
the line that separates the liquid phase from the solid-liquid mixture in a phase diagram
Phase Diagram
a graphical representation of the relationships among temperature (and sometimes pressure), composition, and quantities of the phases of an alloy
Phase
A homogeneous portion of an alloy system that has uniform physical and chemical characteristics
Solute
one component of a solid solution (an alloy) system that has a low concentration and dissolves into a host materials
Solvent
one component of a solid solution (an alloy) system that is the hosting material with the highest concentration.
Solid Solution
a new solid that is formed by adding a substance of a low concentration
(acting as a solute) to a hosting material (acting as a solvent). The crystal structure of the hosting material is maintained, and no new structures are formed.
Alloying
the process of adding impurities to the metal to form a solid solution of better properties
Alloy
a chemical compound of a high concentration of a metal element and other elements including
Isomerism
the phenomenon by which two or more polymer molecules have the same composition but different structural arrangements and properties.
Monomer
A stable molecule from which a polymer is synthesized.
Red Hardness
The material ability to maintain its hardness at elevated temperatures.