3D Finite Element Method Simulations on the Influence of Tool Helix Angle in Thin-Wall Milling Process

In the reported work, a three-dimensional (3D) finite element method (FEM) model was developed to assess the effect of cutter helix angle on milling forces and wall deflection considering thin-wall machining of aluminum 2024-T351 alloy. Johnson-Cook (J-C) constitutive law was employed to model the material flow, whereas the material damage was initiated using the Johnson-Cook damage criterion. Work-tool contact was established using a modified Coulombs friction model. The simulations were carried out for a fixed set of process conditions by varying the helix angle, and the predicted results were experimentally validated. Comparing the milling force and deflection values showed that numerical results augured well with the experimentally measured values. The use of an end mill with a higher helix generated lower force values. Also, a smaller magnitude of wall deflection was noted when 45º and 55º helix tools were used. The experimental investigation into the surface roughness indicated improved shearing action and surface finish when high helix tools were employed.