Effects of magnetic field on discharge point distribution and distortion behavior in WEDM of thin-walled components

Abstract

The geometric error is an important indicator for component performance in Wire Electrical Discharge Machining (WEDM) process, but there are significant and inevitable complex thermal deformation phenomena which lead to large geometric error when machining thin-wall components. This study mainly describes an intricate thermal deformation phenomenon called distortion behavior along the directions of workpiece thickness and cutting path, and figure outs its mechanism of formation and reduction by use of simulation and experimental methods during magnetic assisted WEDM processing the thin-wall component. First of all, the discharge point distributions with and without magnetic assisted technology are experimentally observed, and then the corresponding statistical formulas of discharge point distribution are obtained. Then the thermo-physical model based on above discharge distributions’ formulas are established to simulate the distortion behavior by temperature and residual stress analysis. Furthermore, a comparative experiment is carried out to explore the effect of magnetic field on distortion magnitude of thin-wall samples. The comparison of experimental and simulation results reveals a good consistency between experimental and simulation results. Additionally, the variations of surface integrity with and without magnetic assisted are both measured to investigate the distortion conditions. Eventually, it can be concluded that variation of residual stress and surface integrity show consistent tendency with distortion magnitude and direction, and magnetic field assisted technique is an effective way to reduce distortion behavior.