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

A segregated structure consisting of alternating nearly parallel bands of different composition, typically aligned in the direction of primary hot working.

(1) A reduction of the anodic reaction rate of an electrode involved in corrosion. (2) The process in metal corrosion by which metals become passive. (3) The changing of a chemically active surface of' a metal to a much less reactive state. Contrast with ...

See principal stress (normal).

The lowest value of oxidizing potential at which pits nucleate and grow. It is dependent on the test method used.

Deforming metal plastically under conditions of temperature and strain rote that induce strain hardening. Usually, hut not necessarily, conducted at room temperature. Contrast with hot working.

The property of a material by virtue of which deformation caused by stress disappears upon removal of the stress. A perfectly elastic body completely recovers its original shape and dimensions after release of stress.

A change in dimensions directly proportional to and in phase with an increase or decrease in applied force.

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

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

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.

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

Plating with dummy cathodes.

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

The minimum value of Kc for any given material and condition, which is attained when rapid crack propagation in the opening mode is governed by plane-strain conditions.

A linear imperfection in a crystalline array of atoms. Two basic types are recognized: (1) an edge dislocation corresponds to the row of mismatched atoms along the edge formed by an extra, partial plane of atoms within the body of a crystal; (2) a screw d ...

Coating containing zinc powder pigment andan organic resin.

A raised area, often dome shaped, resulting from (1) loss of adhesion between a coating or deposit and the base metal or (2) delamination under the pressure of expanding gas trapped in a metal in a near-subsurface zone. Very small blisters may be called p ...

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

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