Multiresponse optimization of planar flow melt spinning parameters using the Taguchi-based VIKOR method

The present work focuses on optimizing the planar flow melt spinning process parameters for the fabrication of amorphous Fe-Si-B-Nb-Cu alloy ribbons using a Taguchi-based VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje) approach. The influence of wheel speed, nozzle-to-wheel gap, ejection pressure, and melt temperature was examined through an L ₁₆ orthogonal design with the goal of improving ribbon surface finish and thickness uniformity. The Taguchi method was initially applied to determine individual optimum conditions for each response, while the VIKOR method was employed to perform multiresponse optimization by considering the interaction between process variables. The comparative VIKOR analysis using equal weighting and entropy-based weighting consistently identified the same optimal parameter set (alternative A2), with ε i = 0 (utility measure) and β i = 0 (regret measure) and the lowest VIKOR index ( φ i ) in both cases, demonstrating the robustness and reliability of the optimization framework. The accuracy of the proposed approach was further confirmed using the MOORA (Multi-Objective Optimization on the basis of Ratio Analysis) method, which showed consistent rankings across different weighting conditions. The optimal parameters were identified as a wheel speed of 25  m / s , a nozzle-to-wheel gap of 0.3  mm , an ejection pressure of 14  kPa , and a temperature of 1475 K. Experimental validation under these conditions produced ribbons with a uniform thickness of 47 to 49  μ m , surface roughness of 1.72 to 1.81  μ m , and a complete amorphous structure. The results show that the developed methodology effectively improves process control, enabling efficient production of thin, smooth, and magnetically stable amorphous ribbons.