Chip formation in orthogonal cutting considering interface limiting shear stress and damage evolution based on fracture energy approach

Modeling of metal cutting has proved to be particularly complex, especially for tool-chip interface. The present work is mainly aimed to investigate the limiting shear stress at this interface in the case of Titanium alloy (Ti-6Al-4V) dry cutting based on a FE-model. It was first shown that the surface limiting shear stress is linked to the contact pressure and the coefficient of friction (CoF). A relationship between CoF and the limiting shear stress was given, and the effect of the temperature on the limiting shear stress was also considered. After that, an orthogonal cutting model was developed with an improved friction model through the user subroutine VFRIC in Abaqus/Explicit software. The numerical results obtained were compared with experimental data gathered from literature and a satisfied agreement was found. Finally, the effects of cutting speed, CoF and tool-rake angle on chip morphologies were analyzed. (C) 2011 Elsevier B.V. All rights reserved.