Influence of tool cutting edge micro-geometry on machining additive manufactured Ti-6Al-4V titanium alloy

Overview & Synopsis

The titanium alloy Ti6Al4V obtained by Additive Manufacturing (AM) have shown exceptional advantages in creating complex geometries and internal structures, making them widely applicable in the aerospace and biomedical industries. However, Ti6Al4V components made by AM only can hardly meet their service requirements. Therefore, AM post-processing is needed in which machining process plays critical role to making it suitable for high-precision and demanding applications. In this case, the material to be removed is not as massive as that in conventional subtractive machining. The tool cutting edge (TCE) microgeometry is thereby of significant influence on the machining process. Therefore, this study aims to investigate such influence experimentally and numerically. At first, constitutive material model was developed and implemented in ABAQUS software, considering material plasticity and damage. A VUMAT subroutine was developed to implement the proposed constitutive material model in this finite-element simulation software. On this basis, an improved numerical model based on Lagrangian formulation without sacrificial layer (LAG-nSL) was developed for machining with special consideration of TCE microgeometries. Its advantages in predicting machining process variables were validated by comparisons with the other type of numerical models. Finally, orthogonal cutting tests of AM Ti6Al4V were performed using tools prepared with various TCE. By comparing the measured temperature distribution and forces with those from numerical simulations, it is found that the developed numerical model presents a good accuracy in prediction of these process variables. This study could offer theoretical support for optimization of cutting parameters and tool design in AM prost-processing by machining of Ti6Al4V components.