ON THE CLOSED-FORM MECHANISTIC MODELING OF MILLING - SPECIFIC CUTTINGENERGY, TORQUE, AND POWER

Specific energy in metal cutting, defined as the energy expended in re moving a unit volume of workpiece material, is formulated and determin ed using a previously developed closed form mechanistic force model fo r milling operations. Cutting power is computed from the cutting torqu e, cutting force, kinematics of the cutter, and the volumetric materia l removal rate. Closed form expressions for specific cutting energy we re formulated and found to be functions of the process parameters: pre ssure and friction for both rake and flank surfaces and chip flow angl e at the rake face of the tool. Friction is found to play a very impor tant role in cutting torque and power. Experiments were carried out to determine the effects of feedrate, cutting speed, workpiece material, and flank wear land width on specific cutting energy. It was found th at the specific cutting energy increases with a decrease in the chip t hickness and with an increase in flank wear land.