Contact Wear

Transmitted Oblique Off Crossed Circular Polarized Light and Darfield Reflected light Illumination

This copper alloy abrasive wear particle is from an oil sample collected from a 8400kVA transformer. This transformer was reportedly gas blanketed and sealed. This particle is typical of abrasive wear between contacting surfaces. The "corkscrew" shape characteristic of open surface abrasion can't occur between two conforming surfaces. The result is the elongated particle with striations running parallel to the long axis of the particle. This is typical of "contact wear" in electrical equipment. This particle also exhibits an embossed area in the middle of the left part of the particle. The embossed area is not striated but rather is marked by the impression of the surface that moved this particle into the oil.