Fuzzy TOPSIS-Based Selection of Laser Beam Micro-marking Process Parameters

The process parameter selection in any machining process is one of the most challenging criteria for effective machining. Selection of an optimal parametric combination always results in efficient machining. In the current work, a fuzzy TOPSIS method for selection of optimal laser beam micro-marking process parameters, such as current, pulse frequency, and scanning speed, during laser beam marking on gallium nitride is adopted. Response surface methodology (central composite design) is adopted for the experimental design. The mark width, mark depth, and mark intensity are considered as the process responses. The mark width and mark depth are measured with the help of a precision optical microscope. Microscopic images are then treated using image processing software to calculate the mark intensity. A multi-criteria decision-making model is developed considering the effect of process parameters on process response for selection of optimal process parameter in the laser beam micro-marking process. The triangular fuzzy number is used to calculate the weight of each performance criteria, and the fuzzy TOPSIS hybrid approach is used for selection of optimal parametric combination. The results indicate that a small pulse frequency and high current and scanning speed lead to increase in mark intensity.