Parametric optimisation of Nd:YAG laser micro-drilling of alumina using NSGA II

摘要

Laser micro-drilling is potent enough to replace the mechanical removal methods in many industrial applications especially for machining of difficult-to-cut materials like ceramics and composites. In the present study, laser micro-drilling of alumina has been investigated experimentally. Nd:YAG laser of wavelength of 1.06 μm is used to investigate process parameters such as lamp current, pulse frequency, air pressure and pulse width. Response surface methodology is adapted to perform experimental design and also to develop the mathematical relationships relating input and output process parameters. Since the responses are conflicting in nature, it is difficult to obtain a single combination of cutting parameters satisfying both the objectives in any one solution. Therefore, it is essential to explore the optimisation landscape to generate the set of dominant solutions. Further, this study adapted non-dominated sorting genetic algorithm II (NSGA II) to optimise the responses such that a set of mutually dominant solutions are found.