Effects of machining parameters and tool geometry on serrated chip formation, specific forces and energies in orthogonal cutting of nickel-based super alloy Inconel 100

Abstract

Nickel-based alloys are widely used in applications requiring high strength at elevated temperatures such as in aircraft jet engines. However, nickel-based alloys such as Inconel 100 are still considered difficult-to-machine metal alloys. In this study, specially designed orthogonal cutting tests on Inconel 100 nickel-based alloy have been conducted using WC/Co cutting tool with two varying rake angles, cutting edge radii and at wide ranges of cutting speed and feed. Effects of those parameters on specific forces have been investigated. Serrated and segmented chip formation is observed and the mechanics of segmented chip have been modeled and validated using the experimental test data. Chip microscopic images are utilized in measuring and calculating chip formation angles, shear strain, and shear strain rate in the main shear zone and within the shear bands. It was found that segmentation is highly influenced by machining conditions, and energy distributions calculated with regard to machining parameters reveal that friction dissipation and material separation are significant in machining of Inconel 100 nickel-based alloy.