Component Failure Analysis

Abrasion

• Roughened scratches or marks occur due to foreign matter between moving parts or surfaces.

Brinelling

• One or more indentations present on bearing races.
• Typically caused by high static loads or force during installation/removal.
• Indentations are rounded/spherical due to the impression from balls/rollers.

Burning

• Surface damage results from excessive heat.
• Can be due to improper fit, defective lubrication, or over-temperature operation.

Burnishing

• Polishing of a surface occurs through sliding contact with a smooth, harder surface.
• Usually involves no metal displacement or removal.

Burr

• A sharp or roughened metal projection typically results from machining.

Chafing

• Wear arises from rubbing between two parts under light pressure.

Chipping

• Pieces of material break away.
• Usually caused by excessive stress concentration or careless handling.

Corrosion

• Metal loss occurs through chemical or electrochemical action.
• Corrosion products are easily removed mechanically, like iron rust.

Crack

• Partial material separation is caused by vibration, overloading, internal stresses, defective assembly, or fatigue.
• Depth varies from thousandths of an inch to the full piece thickness.

Cut

• Metal loss occurs to a significant depth over a narrow area by mechanical means.
• Examples include a saw blade, chisel, or sharp-edged stone.

Dent

• Small, rounded surface depression results from being struck by a rounded object.

Erosion

• Metal loss from the surface occurs due to mechanical action by foreign objects like grit or sand.
• Affected area is rough and potentially lined in the direction of the foreign material's movement.

Flaking

• Small pieces of metal or coated surfaces break loose.
• Typically caused by defective plating or excessive loading.

Fretting

• Surface erosion occurs due to minute movement between two parts clamped together under significant unit pressure.

Galling

• Severe chafing or fretting causes metal transfer from one part to another.
• Results from slight movement between mated parts with limited relative motion under high loads.

Gouging

• Furrowing leads to metal displacement (a torn effect).
• Typically caused by a piece of metal or foreign material between moving parts.

Grooving

• A recess or channel with rounded, smooth edges results from faulty alignment.

Inclusion

• Foreign material exists entirely within a portion of metal.
• Such material is introduced during manufacturing of rod, bar, or tubing by rolling or forging.

Nick

• A gouge or depression with a V-shaped bottom is generally from careless handling of tools and parts.

Peening

• A series of blunt depressions on a surface.

Pick Up or Scuffing

• Metal builds up or rolls from one area to another.
• Typically caused by insufficient lubrication, clearances, or foreign matter.

Pitting

• Small hollows of irregular shape exist on the surface.
• Usually caused by corrosion or minute mechanical chipping.

Scoring

• Deep scratches are caused by foreign particles between moving parts, or careless assembly/disassembly.

Scratches

• Shallow, thin lines or marks vary in depth and width.
• Caused by fine foreign particles during operation or contact with other parts during handling.

Stain

• Local color change leads to noticeably different appearance

Upsetting

• Material displacement occurs beyond the normal contour or surface (a local budge or bump).
• Usually indicates no metal loss