Analytical model of work hardening and simulation of the distribution of hardening in micro-milled nickel-based superalloy

Abstract

During the process of micro-milling nickel-based superalloy, the cutting surface is strengthened along with the high strain and strain rate, which leads to work hardening and affects the quality of parts and the tool’s life. At present, there are few analytical models that can predict the micro-hardness of the micro-milled surface. Therefore, the authors focus on the research of the micro-milling work hardening of nickel-based superalloy. Firstly, based on the stress-strain relationship and strain-hardening characteristics of Inconel718, the relationship between hardness and strain of Inconel718 is obtained. Then, based on the established micro-milling force model, the stress of a point in the process of micro-milling is derived. Finally, the surface hardness value of the machined surface is predicted by combining the relationship between the stress-strain and the hardness of the workpiece. In addition, a 3D simulation model of micro-milling nickel-based superalloy groove is established by Deform-3D software to research the distribution of micro-hardness of the machined surface. The research offers reference for improving the surface integrity and fatigue performance of micro-milling nickel-based superalloy and explores a feasible way for revealing the mechanism of micro-milling hardening.