The Conflicting Roles of Carbontetrachloride as a Boundary Lubricant

Abstract

Under certain conditions, carbontetrachloride is found to be a negative boundary lubricant (gives a higher coefficient of friction than that of dry surfaces in air), while under other conditions, it lowers friction and gives a beneficial effect. Both of these situations are illustrated for heavily loaded sliding surfaces where the subsurface is undergoing gross plastic flow and an explanation is presented which appears to be consistent with all experimental facts. Carbontetrachloride is found to be more reactive chemically when the sliding surfaces are heavily strained or galled under high normal and shear stresses and containing microcracks, a situation that arises when cutting at low speed.