CONSIDERATIONS ON THE THEORY OF FRICTION: FRICTION WITHOUT WEAR

Abstract

From studies of the friction between metal surfaces it has been possible to form a new concept of friction in relation to wear. Its basis is the fact that certain intermetallic compounds are unlikely to stick on common metals. Friction can be produced by adding a small amount of metal to the intermetallic compound and it is shown theoretically that the condition of friction without wear is then achieved. The elastic vibrations produced in the metals lead to the necessary sticking followed by shearing to cause friction. Practical results are given where the lives of clutches have been prolonged by factors of up to 100; similar improvements are gained for the brakes of trains and aircraft. New phenomena are explained that limit the life of the friction materials even though wear is negligible.