Initial Period of Chip Formation: Observations Towards Enhancing Machining Sustainability

Abstract

In machining, high mechanical and thermal loads are exerted on a small area of the tool where it interacts with the workpiece. Despite limited interaction space, extensive use of cutting fluids (CFs) is inefficiently used to improve the machining process and increase productivity. In order to minimize CFs’ negative impact on health, environment and financial burden, various strategies have been developed and studied to optimize their use including minimum quantity lubrication. In this research, initial period of chip formation (IPCF), that occurs during a narrow window of space and time at the beginning of the cut, is closely investigated in an orthogonal machining setup. During IPCF, low mechanical loads were observed. The existence of IPCF is further investigated under interrupted cutting process at prescribed intervals in order to sustain its positive effects. In addition, 2D numerical chip formation friction model is proposed. The numerical model comprises a friction criterion dependent on tool temperature that is observed to be associated with a transient friction regime.