Numerical Modelling of Microstructure Evolution in Ti6Al4V Alloy by Ultrasonic Assisted Cutting

Abstract This paper aims to reveal the influence of ultrasonic assisted cutting (UAC) on the microstructure of machined surface in Ti6Al4 V alloy. In order to investigate the microstructure evolution, an enhanced material constitutive model with the temperature dependent material properties of Ti6Al4 V alloy is presented. The study also performs a comparison of cutting and thrust forces in conventional cutting (CC) by using three models, and the Calamaz modified Johnson-Cook model meets the experimental results well. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) model for Ti6Al4 V alloy is utilized to predict dynamic recrystallization (DRx) and resultant grain size. Five points under machined surface are tracked to reflect the evolution of dynamic recrystallization grain size and average grain size subjected to CC and UAC. Further simulations of different vibration amplitudes and cutting parameters are performed, and the comparison between CC and UAC presents the change of average grain size of UAC is smaller than that of CC, thus showing the UAC can achieve low damage processing.