In a cathodic protection system, in electrically nonconductive material, such as a coating, plastic sheet or pipe that is placed between an anode and an adjacent cathode to avoid current wastage and to improve current distribution, usually on the cathode.

The electrode of an electrolytic cell at which reduction is the principal reaction. (Electrons How toward the cathode in the external circuit.) Typical cathodic processes are cation' taking up electrons and being discharged, oxygen being reduced. and the ...

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 ...

The thermodynamic function 3G = 5H - TSS, where H is enthalpy, T is absolute temperature. and S is entropy. Also called free energy, free enthalpy, or Gibbs function.

A metal plating process wherein the plating current is provided by galvanic action between the work metal and a second metal, without the use of an external source of current.

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 ...

Corrosion resulting from an electrochemical cell caused by a thermal gradient.

The degradation of a solid body resulting from its exposure to cavitation. This may include loss of material, surface deformation, or changes in properties or appearance.

The partial derivative of the total electrochemical free energy of a constituent with respect to the number of moles of this constituent where all factors are kept constant. It is analogous to the chemical potential of a constituent except that it include ...

A term primarily used in Europe to describe galvanic corrosion between dissimilar metals.

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 ...

The current density, often referred to as limiting current density, that corresponds to the maximum transfer rate that a particular species can sustain because of the limitation of diffusion.

Polarization of the cathode; change of the electrode potential in the active (negative) direction due to current flow; a reduction from the initial potential resulting from current flow effects at or near the cathode surface. Potential becomes more active ...

Pertaining to the body-centered cubic crystal structure (BCC) of many ferrous (iron-base) metals.

Embrittlement of ultrahigh-strength steels caused by tempering in the temperature range of 205 to 400

See copper-accelerated salt-spray test.

A metallic connection that provides electrical continuity between metal structures.

The interface between an eletrode or a suspended particle and an electrolyte created by charge-charge interaction (charge separation) leading to an alignment of oppositely charged ions at the surface of the electrode or particle. The simplest model is rep ...

The maximum stress that presumably leads to fatigue fracture in a specified number of stress cycles. If the stress is not completely reversed. the value of the mean stress. the minimum stress, or the stress ratio should also be stated. Compare with endura ...

An electrode in an electrolytic cell that is not mechanically connected to the power supply, but is so placed in the electrolyte, between the anode and cathode, that the part nearer the anode becomes cathodic and the part nearer the cathode becomes anodic ...