A term generally applied to paints to describe holidays, holes, and skips in a film. Also used to describe shrinkage in castings and weld.

Imparting resistance to oxidation to an iron or steel surface by heating in aluminum powder at 800 to 1000

A chromate conversion coating produced on magnesium alloys in a boiling solution of sodium dichromate.

Plating with dummy cathodes.

Any interruption in the normal physical structure or configuration of a part, such as cracks, laps, seams, inclusions, or porosity. A discontinuity may or may not affect the usefulness of the part.

A measure of proportion by weight, equivalent to one unit weight of a material per million (106) unit weights of compound. One part per million is equivalent to l mg/g

One or more anodes installed vertically at a nominal depth of 15 m (50 ft) or more below the earth's surface in a drilled hole for the purpose of supplying cathodic protection for an underground or submerged metallic structure. See also groundbed.

Current efficiency at the cathode.

The formation and instantaneous collapse of innumerable tiny voids or cavities within a liquid subjected to rapid and intense pressure changes. Cavitation produced by ultrasonic radiation is sometimes used to effect violent localized agitation. Cavitation ...

Change of electrode potential with respect to a reference value. Often the free corrosion potential is used as the reference value. The change may be caused, for example, by the application of an external electrical current or by the addition of an oxidan ...

(1) Injection of air or water under high pressure through a tube to the anode area for the purpose of purging the annular space and possibly correcting high resistance caused by gas blocking. (2) In connection with boilers or cooling towers, the process o ...

The selective leaching or corrosion of a specific constituent (Al, Ni, Mo, Ni) from an alloy.

A strongly alkaline solution into which metal is immersed for etching. for neutralizing acid, or for removing organic materials such as greases or paints.

A fractographic pattern of radial marks (shear ledges) that look like nested letters "V"; sometimes called a herringbone pattern. Chevron patterns are typically found on brittle fracture surfaces in parts whose widths are considerably greater than their t ...

Corrosion occurring under or around a discontinuous deposit on a metallic surface. Also called poultice corrosion.

See principal stress (normal).

Provisional value for plane-strain fracture toughness.

The fracture toughness determined under dynamic loading conditions; it is used as an approximation of KIc for very tough materials.

See copper-accelerated salt-spray test.

A chemical substance or mixture that prevents or reduces the rate of the cathodic or reduction reaction by physical, physico-chemical or chemical action.