This proposed work is to develop a new cutting force model for chip breaking in machining with a conventional grooved tool insert. This is expected to be accomplished using a recently established force model for machining with a flat-faced (non-chip forming) tool. The proposed work will involve analytical modeling of the process of chip breaking process for conditions requiring consideration of additional forces at the free-end of the chip as well as at the back-wall of the chip groove. Variable frictional conditions will be assumed at the chip/tool back-wall and chip/work surface contact points. The well known shear plane theory of metal cutting will be extended to include the effects of the above additional friction forces. Experimental work will include the use of a high speed filming camera system to study the varying chip curling and breaking patterns within a typical chip breaking cycle while continuously monitoring the cutting force variations with the use of a three-component tool dynamometer system. Based on the analytical simulations and the experimental work, it is expected to model the curled chip using the finite element modeling technique for continuously varying chip loading. The variation of mechanical properties such as the tensile strain which normally contribute to the chip breaking process will be estimated. The major objective of this work is to establish the most significant factors that influence chip breaking and to develop a new chip breakability criterion based on the new findings. It is hoped that the new findings anticipated in this project will help cutting tool manufacturers in designing new and innovative chip forming tool inserts.
