Experimental investigation on friction law under starved lubrication in metal forming

Abstract

Friction law under starved lubrication is investigated by friction tests under a wide range of the average pressure. The lubricant thickness applied to the specimen surface for friction test is controlled to four levels; very thin, fourth, half and twice of the surface roughness of specimen. Experimental results showed that the friction law under the lubricant thickness of very thin is similar to that under dry condition. When the lubricant thickness is large enough, Coulomb friction is applicable even under very high pressure.