A Fundamental Study on Gas Film Formation and its Effect in Electrochemical Discharge Machining Process

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Advanced engineering materials and alloys possess excellent physical properties. However, machining these materials by traditional methods is difficult due to their hardness, brittleness, and other characteristics, leading to increased tool wear and surface damage. This award supports a fundamental study of electrochemical discharge machining (ECDM) - a nontraditional process that improves the surface integrity of advanced engineering materials that are critical for the US economy and national security. Using modeling, simulation and experimental methods, the formation and stability of gas film in the ECDM of advanced materials will be studied. The topography, mechanical and tribological properties, and composition of the machined surface will be analyzed subsequently. The expected improvement in the machinability of a wide variety of both conductive and nonconductive materials will help in unleashing the full application potential of these materials in biomedical, electronic, automotive, and energy industries. Potential applications in these industries include hip joint prosthesis, electronics packaging, brake linings, and solid oxide fuel cells. The multi-disciplinary approach and results of this study can be extended to other electrical machining processes. The outcome of this project will be integrated into graduate and undergraduate courses, and training and learning within female and underrepresented minorities. The results of this research will be disseminated through peer-reviewed publications, presentations at professional society meetings, and YouTube videos.Through this research, fundamental knowledge on the mechanism of gas film formation and stability during the electrochemical discharge machining process will be generated by conducting analytical and experimental investigations to understand the effect of thickness and stability of the gas film on the surface integrity changes in machined parts. Critical insight into the rate of gas bubble formation, the rate of coalescence, and the gas film thickness will be acquired by molecular dynamics simulations to produce stable and thin gas film. Finite element simulations coupling electrical, chemical and thermal aspects of ECDM will be pursued to investigate the hydrodynamic behavior of boundary layers during gas film formation. Multi-physics based mathematical models will be developed to predict the gas film thickness, discharge energy and surface roughness in ECDM. Sensor fusion of optical and electrical feedback signals will be used in the experimental studies for in-process monitoring and control.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.