Multi-response optimization of machining parameters in micro milling of alumina ceramics using Nd:YAG laser

Laser micro milling by material ablation is a growing technology for developing micro features in a wide range of materials and offers various advantages in terms of both product quality and process efficiency. In contrast, other non-traditional methods such as micro electro-discharge machining, ion milling or lithography are material dependent, slow and often associated low dimensional accuracies. This paper considers the analysis and multi-response optimization of machining parameters during Nd:YAG laser micro milling of Alumina ceramic using MOGA-II. MOGA-II is a multi-objective genetic algorithm that uses a new smart multi-search elitism operator for optimization. The results show that the pulse intensity and pulse overlap have a significant effect on the depth of the machined cavity and surface roughness. Better surface finish for micro-milled alumina ceramic is obtained with low pulse overlaps, high intensities, low frequencies and shorter pulse durations. Whereas material removal rate (MRR) is mostly influenced by intensity of the laser beam and the high material removal rates are associated with high laser beam intensities.