Grinding Wear Caused by Fine Particles

Mechanical wear is the progressive loss of material from a surface due to contact and friction with another surface. Such wear can significantly reduce the operational lifespan of equipment.

Lubricating oil mitigates against the friction by creating a thin film between surfaces. This film is commonly up to 5um in thickness; although in heavy machinery can be much thicker. The surfaces themselves, even in precise machinery, can have separation distances up to 20um.

Where the oil contains hard microscopic particulate matter of the size and greater than the oil film, this then becomes a source of contact and friction between surfaces, which causes further hard microscopic particulate matter to be created and contaminate the oil. Hard particulate matter of the size of the separation distances between surfaces can also cause mechanical jamming in addition to wearing.

The below video gives an audio indication of the effects of mechanical wearing due to microscopic hard particulate matter.

The gritty grinding that results is easily felt in the fingers and heard in the audio – oil contamination causes wear, and wear causes further oil contamination.  If oil is kept clean, this process simply does not take place.