3D FE modelling of the cutting of Inconel 718

Following a literature review, the paper outlines the development of a 3D finite element model for the turning of Inconel 718 using ABAQUS/Explicit as a precursor to ball end milling simulation. The model employed a Lagrangian formulation. The workpiece material property data were determined from experimental work on a Gleeble thermo-mechanical simulator using uniaxial compression testing, with temperatures and strain rates of up to 850degreesC and 100 s(-1), respectively. Predicted and measured forces were within 6% for the tangential component, while feed forces were within 29%. The actual chip morphology determined from quick-stop experiments was segmented, whereas the predicted profile was continuous, irrespective of the cutting speed. It is likely that the discrepancies were a result of over-simplification of the friction model together with inadequacies in the algorithms describing the material behaviour. A user sub-routine which contains a 'damage criterion' to initiate crack propagation has been highlighted as a requirement to simulate chip segmentation. Details of preliminary work on the 3D ball nose end milling of Inconel 718 are also presented, which underline the difficulties inherent in this approach, together with geometry and mesh considerations. (C) 2004 Elsevier B.V. All rights reserved.