Serrated Chip Morphology and Comparison with Finite Element Simulations

The complexity of chip formation in machining processes stems from the confluence of several physical phenomena mechanical, thermal, and chemical occurring at very high strain rate. The prediction of chip morphology depends on a fundamental understanding of these phenomena and is of industrial importance for cutting force prediction and surface integrity control. Within this framework, our paper focuses on the modelling of serrated-chip formation (saw-tooth shape chip) and on the physical phenomena accompanying the serrated-chip formation according to the variation of feed rate. In the first part, bibliography review and experimental study on chip formation is made. The experimental study, based on metallographic analysis of chip morphology, focuses on the machining of an American Iron and Steel Institute (AISI) 4340 steel alloy work material. The second part of the paper deals with the FEM model to simulate cutting processes using the Abaqus explicit code and Third Wave Systems Advantedge software. The simulations utilize plasticity models for material behaviour and damage to predict chip morphology. The third section proposes a comparison of simulations results with experimental observations. Experimental results support the results of the simulations for various cutting parameters. We end the paper with some concluding remarks.