Analytical Predictive Modeling of Serrated Chip Formation in High Speed Machining of 7075-T6 Aluminum Alloy

Abstract

High speed machining has received increasingly broad applications in various industries, especially in the aircraft and aerospace industry, where a large number of structural frames are machined. Based on Manyindo and Oxley’s descriptive model of serrated chip formation, this paper proposes a new mathematical model for high speed machining of 7075-T6 aluminum alloy. The new model integrates Johnson-Cook’s material model with Oxley’s machining theory and is validated by using the published experimental data. A good agreement between the predicted and experimental degree of chip segmentation is reached. The effects of cutting conditions and tool geometry on the serrated chip geometry, the cutting forces, and the shear-plane angles are quantitatively investigated. The analysis shows that a large undeformed chip thickness, a negative tool rake angle, and a high cutting speed strengthen the degree of chip segmentation in high speed machining.