A scaling factor, usually denoted by the symbol K, used in linear-elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape. At the onset of rapid crack propagation in any structure containi ...

(1) The application of an electrically conductive metallic layer to the surface of nonconductors. (2) The application of metallic coatings by nonelectrolytic procedures such us spraying of molten metal and deposition from the vapor phase.

A coating process whereby thermally emitted electrons collide with inert gas atoms, which accelerate toward and impact a negatively charged electrode that is a target of the coating material. The impacting ions dislodge atoms of the target material, which ...

Hardening caused by the precipitation of a constituent from a supersaturated solid solution. See also age hardening and aging.

The maximum or minimum value at the normal stress at a point in a plane considered with respect to all possible orientations of the considered plane. On such principal planes the shear stress is zero. There are three principal stresses on three mutually p ...

A loss ofstrength and ductility of .steel by high-temperature reaction of absorhcd hydrogen with carbides in the steel resulting in dec arbwri:.alien and internal fissuring.

A coating process whereby the cleaned and masked component to be coated is heated and rotated on a spindle above the streaming vapor generated by melting and evaporating a coating material source bar with a focused electron beam in an evacuated chamber.

Any of various functions from which intensity or velocity at any point in a field may be calculated. The driving influence of an electrochemical reaction. See also active potential, chemical potential, corrosion potential, critical pitting potential, deco ...

The opposition that a device or material offers to the flow of direct current, equal to the voltage drop across the element divided by the current through the element. Also called electrical resistance.

Fracture through or across the crystals or grains of a metal. Also called transcrystalline fracture or intracrystalline fracture. Contrast with intergranular fracture.

See corrosion potential and open-circuit potential.

An accelerated corrosion of' metal surfaces that results from the combined elTect of oxidation and reactions with sulfur compounds and other contaminunts, such us chlorides, to form a molten salt on a metal iurfuce that f1uxes, destroys, or disrupts the n ...

The threshold value of the corrosion potential that has to be reached to enter a protective potential range. The term used in cathodic protection to refer to the minimum potential required to supress corrosion.

The time rate of straining for the usual tensile test. Strain as measured directly on the specimen gage length is used for determining strain rate. Because strain is dimensionless, the units of strain rate are reciprocal time.

Artificial aging in which a constituent precipitated from a supersaturated solid solution.

The unit of change in the size or shape of a body due to force. Also known as nominal strain.

A general term for the emhrittlement, cracking, blistering. and hydride formation that can occur when hydrogen is present in some metals.

Pertains to the machining characteristics of an alloy to which one or more ingredients have been introduced to give small broken chips, lower power consumption, better surface finish, and longer tool life; among such additions are sulfur or lead to steel, ...

Factor for a loading condition that displaced the crack faces in a direction normal to the crack plane (also known as the opening mode of deformation).

A multiplying factor for applied stress that allows for the presence of a structural discontinuity such as a notch or hole; Kt equals the ratio of the greatest stress in the region of the discontinuity to the nominal stress for the entire section. Also ca ...