Parametric analysis and multi response optimization of laser surface texturing of titanium super alloy

The present research deals with laser surface texturing (LST) on titanium super alloy considering four important LST parameters viz. average power, pulse frequency, scan speed and gas pressure. The material removal rate (MRR) and average texture width (ATW) are evaluated at various parametric combinations. Experiments are conducted on a multi-diode Nd: YAG laser as per a L16 orthogonal array design. The main effects and the interaction effect of the four LST variables on the two responses i.e., MRR and ATW are studied. To simultaneously optimize all the LST parameters such that the desired performance of the responses is achieved multi-criteria decision-making (MCDM) method is used. Hybrid-MCDM formulations are introduced in this paper by using Preference Selection Index (PSI) in conjunction with Technique for order preference by similarity to the ideal solution (TOPSIS) and Evaluation based on Distance from Average Solution (EDAS). The hybrid PSI-TOPSIS and PSI-EDAS are evaluated by comparing with three popular objective methods (viz. mean-weight method, standard deviation method and entropy method) of weight allocation to criteria. It is observed that except for Entropy-TOPSIS and PSI-TOPSIS all other methods predict A3B4C3D3 as the optimal process parameter combination.