Definitions of terms for mechanical & metallurgical wear & force failure

Terms are in alphabetical order. Please click on the relevant section to jump to that section of the list.

A-E

Abrasive Wear (Cutting Wear)/Scouring Abrasion: The act of wearing or rubbing off outer layer.

Adhesive Wear - A sticking together of the surface of bodies.

Atomic Wear - Wear between two contracting surfaces in relative motion attributed to migration of individual atoms from one surface to another.

Brinelling - Damage to a solid bearing surface characterized by one or moreplastically formed indentations brought about by overload.

Catastrophic Wear - Sudden surface damage, deterioration, or change of shape caused by wear that shortens the life of the product.

Cavitation Erosion (or droplet erosion) - Creating hollow places or voids.

Corrosive Wear/Chemical Wear - The action of eating or wearing away by slow degrees.

Crater Wear (tool steel) - The wear that occurs on the rake face of a cutting tool due to contact with the material in the chip that is sliding along that face.

Craze Cracking - To make small cracks on the surface of, associated with thermal cycling.

Deformation Wear - Sliding wear involving plastic deformation of the wearing surface.

Delamination Wear - A wear process in which thin layers of material are formed and removed from the wear surface.

Electrical Pitting - The formation of surface cavities by removal of metal as a result of an electrical discharge across an interface.

Electrocorrosive Wear - Wear to a solid surface which is accelerated by the presence of a corrosion-inducing electrical potential across the contact interface.

Erosive Wear - The act of eating or wearing away surface due to relative motion in contact with a fluid that contains solid particles.

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F-J

Fatigue Wear - The tendency of a metal to weaken or break down under continuous stress.

Flank Wear (tool steel) - The loss of relief on the flank of a cutting tool behind the cutting edge due to rubbing contact.

Fretting Wear - Wear between tight-fitting surfaces due to small oscillating movements.

Galling, Scoring & Scuffing - To fret and wear away by friction

Gouging Abrasion - To make grooves or holes.

Heat Checking - A process in which fine cracks are formed on the surface of a body in sliding contact due to the build up of excessive frictional heat.

Hydrogen Embrittlement - Low ductility or cracking in metal caused by absorption of hydrogen.

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K-O

Lapping - Rubbing two surfaces together, with or without abrasives, for the purpose of obtaining superior surface finish.

Linishing - A method of finishing by grinding on a continuous abrasive belt.

Oxidative Wear - The act or process of uniting with oxygen (chemical reaction).

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P-T

Pitting - To become marked with pits or depressions.

Polishing Wear - To make smooth and glossy by friction.

Rain Erosion - A form of liquid impingement erosion in which the impinging liquid particles are raindrops.

Ridging Wear - A deep form of scratching in parallel ridges usually caused by plastic flow of the subsurface layer.

Scoring & Scuffing - To fret and wear away by friction

Scratch - A groove produced in a solid surface by the cutting and/or plowing action of a sharp particle moving along that surface.

Seizure - The act of taking sudden hold.

Severe Wear - A form of wear characterized by removal of material in relatively large fragments.

Spalling or Scabbing - To chip or splinter into smaller pieces.

Stress - Corrosion - Cracking due to simultaneous action of corrosion and stress.

Thermal Shock - The development of a steep temperature gradient and accompanying high stresses within a structure.

Thermal Cracking - Occurs when the material changes temperature faster than internal structure can adapt.

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U-Z

Weld Cracking - Occurs when molten weld pool solidifies, cools and contracts. If there is not enough ductility in weld metal, the weld is constrained, or poor weld practice was employed, cracks will precipitate.

Work - Hardening - A method of cold working in which compressive stresses are induced in the exposed surface layers of metallic objects by the impingement of a stream of shot, directed at the metal surface at high velocity and under controlled conditions.

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