Slipline field solutions for metal machining with adhesion friction and elastic effects at the chip-tool contact region

Abstract

Slipline field solutions for orthogonal metal machining are presented by considering elastic effects on chip formation and assuming adhesion friction at the chip-tool interface. The slipline fields are constructed following the matrix operational procedure developed by Dewhurst and Collins and by Dewhurst and assuming a linear relation between the angular range of α and β lines within the secondary shear zone. The limits of validity of the proposed solutions are examined using Hill's overstressing criteria. Elastic, plastic, total cutting, and total thrust forces and contact lengths are computed assuming an exponential pressure distribution in the elastic contact region. Results indicate that for any given rake angle and coefficient of friction the machining parameters are not uniquely determined but may have a range of allowable values and this is due to the non-unique nature of the machining process. Rake angle and rake friction are found to be the most important variables that influence cutting forces, cutting ratio, and contact length. The predicted results show excellent agreement with experimental observations, especially at small rake angles.