A FEA simulation study of ball end mill for fixed 3+1/3+2 axis machining of Ti-6Al-4V

This paper presents a Finite Element Analysis (FEA) simulation study conducted on ball endmill for fixed 3 + 1 and 3 + 2 axis orientations for machining Ti-6Al-4 V. This work adopts a tungsten carbide (WC) (sic)18.6 mm diametrical/6fluted ball endmill to analyse maximum principal elastic strain (epsilon(max-max-principal-elastic)), maximum principal stress (sigma(max-principal)) along with cutting tools forces in the axial (F-z), radial (F-y), tangential (F-x) and total (F-total) directions. The machining orientations considered for 3 + 1 and 3 + 2 axis are (i) tilt angles of 5 degrees, 10 degrees, 15 degrees & 20 degrees and (ii) lead angles of 5 degrees, 10 degrees & 15 degrees with a constant fixed tilt angle of 10 degrees. The cutting speed and feed rate per tooth is taken as 450 m/min and 0.5 mm/tooth. These are based on a high speed machining (HSM) scenario and has been dynamically simulated for a maximum of 175,000 cycles. From the simulation study considered at 16-20 valid cutting points, it can be noticed that in 3 + 1 axis, for a tilt angle of 10 degrees and 3 + 2 axis for a Tilt 10 degrees/Lead 10 degrees the sigma(max-principal) and epsilon(max-max-principal-elastic) are higher when compared with all tilt/lead angles. In case of total forces (F-total) from all 3 directions (F-x, F-y and F-z) not much variation can be noticed for different tilt/lead angles, but higher values are recorded with 3 + 1 axis at 5 degrees tilt angle and 3 + 2 axis at tilt/lead angle of 10 degrees. The paper provides a critical comparative study on the 3 + 1/ 3 + 2 axis orientations highlighting the cutting strain/stress with tool forces at valid cutting points considering entry, middle and exit region of the blank by emphasizing the importance of cutting tool design parameters. (C) 2021 Elsevier Ltd. All rights reserved.