NUMERICAL AND EXPERIMENTAL INVESTIGATION OF LASER-ASSISTED MACHINING OF INCONEL 718

Abstract

A numerical investigation of laser-assisted machining for Inconel 718 is presented. This study is based on a three-dimensional finite element model, which takes into account a new constitutive law of Inconel 718 as well as friction and heat transfer models at the tool-chip interface that are developed at the Aerospace Manufacturing Technology Centre (AMTC), of the National Research Council of Canada (NRC), Canada. The material flow stress is described as a function of the strain, the strain rate, and the temperature. The friction model accounts for the sticking and the sliding regions observed experimentally. The formulation of the heat transfer model is based on combining contact mechanics analysis with the solution of the thermal contact problem. The laser beam is modeled as a moving heat source, which is experimentally calibrated. To validate the three-dimensional finite element model, laser-assisted machining experiments were designed and carried out under different cutting conditions. The predicted cutting force and chip thickness are compared with the experimental results. The temperature, stress, strain, and strain rate fields in the primary deformation zone are investigated in order to reveal the plastic deformation process under laser-assisted machining operations.