Phenomenological study of chip flow/formation and unified cutting force modelling during Ti6Al4V alloy turning operations

Mechanistic approach for prediction of cutting forces are showing limits when it comes to enhance the cutting force modelling for specific applications of high-value added and thin parts, which are made of difficult-to-cut materials such as titanium alloys. This is the reason why precise cutting force modelling is needed in order to avoid deflection during machining. Therefore, this contribution aims to improve the description of the chip formation in cutting force modelling thanks to an original experimental set-up built up to observe in-situ the chip flow and measure the cutting forces during Ti6Al4V turning. This study highlights the fact that the chip flow direction has a significant effect on cutting forces and can be influenced by several parameters. In view of the results obtained, a generalised chip flow direction model is suggested. Chips morphology observation is also conducted with the purpose of providing experimental observations physical meaning. Afterwards, a cutting force model is proposed which takes into account the chip flow direction influence. (C) 2018 The Authors. Published by Elsevier Ltd.