Optimizing magnetic field-assisted WEDM for magnetocaloric material rare-earth Gd thin-walled parts: Measuring thermal deformation and surface characteristics

Thin-walled regenerators made from rare-earth Gd are commonly used to enhance the performance of room-temperature magnetic refrigeration systems. This study investigates thermal deformation (TD) and surface characteristics of thin-walled parts during magnetic field-assisted wire electrical discharge machining. Thermo-mechanical coupling simulations demonstrated that magnetic field (MF) reduces the temperature gradient in thin-walled parts by enlarging the discharge channel radius, thereby mitigating TD effects. The average error of simulation results was 13.95 %. X-ray diffraction measurements indicated the formation of recast layer induced residual stresses, yielding increased TD. Applying an MF of 0.14 T reduced the average thickness of recast layer by 2.5 μm. The effects of process parameters on TD and surface roughness (SR) were studied through Taguchi experiments. The study measured TD and SR, and through a multi-objective particle swarm optimization algorithm, the average errors for the Pareto optimal solutions of TD and SR were 6.95 % and 7.75 %, respectively.