Machining-Induced Work Hardening Behavior of Inconel 718 Considering Edge Geometries

Abstract

As a representative type of superalloy, Inconel 718 is widely employed in aerospace, marine and nuclear industries. The significant work hardening behavior of Inconel 718 can improve the service performance of components; nevertheless, it cause extreme difficulty in machining. This paper aims to investigate the influence of chamfered edge parameters on work hardening in orthogonal cutting of Inconel 718 based on a novel hybrid method, which integrates Coupled Eulerian-Lagrangian (CEL) method and grain-size-based functions considering the influence of grain size on microhardness. Orthogonal cutting experiments and nanoindentation tests are conducted to validate the effectiveness of the proposed method. The predicted results are highly consistent with the experimental results. The depth of work hardening layer increases with increasing chamfer angle and chamfer width, also with increasing feed rate (the uncut chip thickness). However, the maximum microhardness on the machined surface does not exhibit a significant difference. The proposed method can provide theoretical guidance for the optimization of cutting parameters and improvement of the work hardening.

INCONEL® Alloy Machining and Tool Wear Finite Element Analysis Assessment: An Extended Review

“…INCONEL ® machinability modelling in FEA must rely on a proper damage evolution model. Since INCONEL ® 718 and 625 present elastoplastic behaviour, as shown in Figure 2, from T 0 through different T values until reaching T ≈ 1200 • C, a ductile material damage model is the most suitable [52][53][54][55][56][57][58] to predict the damage caused by machining.…”

“…These fracture-energy-based criteria have been widely used for machining simulations, particularly Hillerborg's fracture energy criterion [54][55][56]. The model's second form of the equation is solved in order to obtain u p , a change of variable that is very useful so that u p f can be calculated according to Equation (13):…”