CHIP STRUCTURE CLASSIFICATION BASED ON MECHANICS OF ITS FORMATION

Understanding chip formation is the first step to good chip control, a necessity for automated machining. Such understanding results in the prediction of chip breakability for a wide range of machining conditio ns. This paper presents a generalized model of chip formation in metal cutting. The mechanical properties of the workpiece are of prime conc ern. A new classification of chip structure is proposed, according to which classification, seven different chip structures are distinguishe d, namely: the regular broken chip, the irregular broken chip, the con tinuous fragmentary chip, the continuous fragmentary chip with a wedge -shaped texture, the continuous chip, the continuous hump-back chip, a nd the fragmentary hump-back chip. Unlike the known classifications wh ich often have a post-process nature, the proposed classification cons iders the chip structure, the chip stress and strains as the results o f chip-formation dynamics. The methodology presented in this paper pro vides a new and viable means to predict chip breakability. The results of this study give clear ideas to the tool designer, technologist, or even to the foreman, as to what kind of chip-breaking should be used for a given set of machining conditions. (C) 1997 Elsevier Science S.A .