White Layer Formations at Machined Surfaces and Their Relationship to White Layer Formations at Worn Surfaces

Abstract

This paper describes the results of a deep drilling investigation in which white layers are formed at a hole surface by a combination of high temperatures, pressures, strain rates, cooling rates, and cyclic deformation. A comparison is drawn between the mechanisms involved in deep drilling and thermo-mechanical mechanisms present during rubbing. This comparison provides a clue as to how white layers are created during other machining processes, examples being given for drilling, milling, and grinding.