Evaluation of different tool geometries in the finite element simulation of ultrasonic-assisted drilling of Ti6A14V

This paper attempts to analyze the effect of various drilling parameters such as feed rate, spindle speed and vibration frequency on performance characteristics such as thrust force, effective stresses, temperature and chip morphology in conventional drilling (CD) and ultrasonic-assisted drilling (UAD) of Ti6A14V using three different point angle (140 degrees, 120 degrees, 90 degrees) drill bits in order to optimize the chip breakability of Ti6A14V. The three different point angle drill bits are utilized to establish the finite element models (FEM) to simulate the drilling process with Lagrangian approach in DEFORM-3D software. The simulations are validated by the experimental findings and analytical data of thrust forces, and the percent errors in results range approximately between 3 and 7%. The results obtained prove that UAD can produce segmental discontinuous chip, lower thrust force, lower process temperature and lower effective stress. The point angle of 120 degrees drill achieved the thinnest chip thickness and the excellent effects of chip breaking. The achieved results are assumed to help for the optimization of the drill tool geometries, drilling parameters and chip breakability.