Residual stresses prediction in machining of Inconel 718 superalloy using a constitutive model considering the state of stress

Abstract

The need for developing new products that meet high functional requirements, such as high fatigue strength, superior thermal and corrosion resistance, have permitted to focus on the development of enhanced materials and seek solutions that also promote better surface integrity. It is the case of the Inconel 718 nickel superalloy, where the combination of its mechanical and thermal properties provides a full industrial application, especially in hot engine components in the aerospace industry. However, there is still a big challenge to obtain suitable surface integrity for this kind of application after machining this alloy. This work aims to predict the surface integrity in the machining of the Inconel 718 alloy using an orthogonal cutting model implemented in Abaqus FEA software. This model includes a constitutive model considering the most relevant factors affecting the mechanical behavior of Inconel 718 in machining, including the strain rate and the state of stress. The machining model is validated by comparing the measured and predicted results. Then, it is used to evaluate the influence of the cutting regime parameters and tool geometry on the residual stresses.