| The interface between the chip and the tool in machining is critical for determining power consumption, surface finish, and other properties of the machined surface. The friction mechanism developed within the interface consists of a region of seizure friction where a solid phase bond exists between the chip and tool and a region of sliding friction.; Aiding conventional machining operations with ultrasonic vibration is one possibility to eliminate or reduce the seizure friction and improve the surface integrity of machined products. In this research: (1) an ultrasonic motor designed to produce a standing wave propagating from the cutting edge of the tool, (2) a mathematical model is developed which relies upon measured data to estimate the seizure length during orthogonal cutting, and (3) a Hertzian contact mechanism using the concepts of adhesion and interfacial bonding energy introduced to explain the modifying process upon seizure friction after applying ultrasonic wave into the tool-chip interface.; This contact mechanism is verified experimentally with an oscillating tool which cuts various work materials with different adhesion nature related to tool. It is found that the tool equipped with an ultrasonic motor can reduce seizure friction and accelerate the chip which leads to reduced cutting forces. |
