A type of wear that occurs between tight-fitting surfaces subjected to cyclic relative motion of extremely small amplitude. Usually, fretting is accompanied by corrosion, especially of the very fine wear debris.

Current flowing through paths other than the intended circuit.

A molecule usually an organic compound, having the ability to join with a number of identical molecules to form a polymer.

Any aquatic organism with a sessile adult stage that attaches to and fouls underwater structures of ships.

The occurrence of embrittlement in a material below the melting point of the embrittling species. See also liquid-metal embrittlement.

See intergranular cracking.

An alloy having an amorphous or glassy structure. See also amorphous solid.

A range of corrosion potential values in which unacceptable corrosion resistance is achieved for a particular purpose.

A thermal spraying process in which the coating material is melted with heat from a plasma torch that generates a nontransferred arc: molten coating material is propelled against the base metal by the hot, ionized gas issuing from the torch.

Descriptive treatment of fracture, especially in metals, with specific reference to photographs of the fracture surface. Macrofractography involves photographs at low magnification (< 25x); microfractography, photographs at high magnification (>25x)

Heat treatment carried out in steel to reduce internal stresses.

The stress condition in linear elastic fracture mechanics in which the stress in the thickness direction is zero; most nearly achieved in loading very thin sheet along a direction parallel to the surface of the sheet. Under plane-stress conditions, the pl ...

A twisting deformation of a solid body about an axis in which lines that were initially parallel to the axis become helices.

A method of fracture analysis that can determine the stress (or load) required to induce fracture instability in a structure containing a cracklike flaw of known size and shape. See also fracture mechanics and stress-intensity factor.

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 ...

The potential of an electrode in an electrolytic solution when the forward rate of a given reaction is exactly equal to the reverse rate. The equilibrium potential can only be defined with respect to a specific electrochemical reaction.

That type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact.

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 ...

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.

See biological corrosion.