Numerical analysis of the formation of the dead metal zone with different tools in orthogonal cutting

摘要

This work focuses on the mechanism of the dead metal zone (DMZ) formation and the effects of the cutting edge geometries (sharp, chamfered, double chamfered and blunt edges) and the cutting speed as well as the coefficient of friction on the formation of DMZ during orthogonal cutting of AISI 1045 material using finite element method (FEM). The different tool edge geometries are utilized to establish the finite element models to simulate the cutting process with Arbitrary Lagrangian-Eulerian (ALE) approach in ABAQUS/Explicit. The simulations are validated by the experimental findings and analytical data of cutting and thrust forces. The experiments are conducted with four kinds of tools at a velocity of 8 m/s and a chamfer tool at three different cutting speeds (4 m/s, 10 m/s and 16.7 m/s). The simulation results show that both the cutting speed and friction coefficient have some effects on the formation of the DMZ due to the thermal softening effect and friction. However, tool edge geometry has large influence on the formation of DMZ because of the missing region created by different edge. The machining forces both in the cutting and thrust directions increases as the size of the DMZ increases and decreases as the cutting speed increases. The DMZ is responsible for the increasing of thrust force. The finite element size is also studied in the paper, the comparisons with different FE sizes show that a smaller size contributes to a more accurate result at the cost of the computing time, so a balance between the accurate results and the computing time should be made. (C) 2015 Elsevier B.V. All rights reserved.