Mechanics of metal cutting and cutting fluid action

Abstract The paper contains an analysis of orthogonal cutting where process geometry is described by the chip compression factor λ and where friction of the rake face is determined by the reduced tool-chip contact length n. The minimum energy principle is applied to a simple upper-bound field and an analytical relationship is found between λ and n. Experimental results, together with data from literature, are compared with the theoretical expression, and the range of validity of the model is discussed. The same model is proposed to explain the action of cutting fluids, a particular feature of the model being that fluid access to the rake face is not required. Three different mechanisms are suggested to account for lubrication in cutting, which generally speaking consists in restriction of the tool-chip contact area. It is proposed to adopt the reduced contact length in efficiency tests for cutting fluids. Experimental results are presented.