Simulation and experimental investigations of complex thermal deformation behavior of wire electrical discharge machining of the thin-walled component of Inconel 718

The geometric error is very important to the component performance in wire electric discharge machining (WEDM) process, yet few studies have focused on the geometric error caused by thermal deformation. This work mainly describes the complex thermal deformation phenomenon and its corresponding cause during the WEDM processing the thin-walled component of Inconel 718. Firstly, the thermo-physical model is developed to explore the thermal deformation by calculating the temperature distribution of workpiece and surface residual stress. Then a number of experiments are conducted to investigate the effect of pulse-on time, pulse current, water pressure, and wire speed on the thermal deformation of thin-walled samples. By the comparison of experimental and simulation results, it was confirmed the reliability and accuracy of thereto-physical model while experimental results revealed that the effects of process parameters of WEDM on the surface integrity as well as thermal deformation scale. Furthermore, we presented their variations of residual stress and surface characteristics including surface topography, micro-hardness, surface elemental composition, and recast layer thickness under different thermal deformation conditions. It can be concluded that the variations of residual stress and surface integrity are almost consistent with that of the thermal deformation.