Optimization of sputtering parameters using MCDM techniques for synthesis of CoCrFeNi medium entropy alloy coatings

The superior mechanical and tribological properties offered by multi-element alloy coatings are drawing significant attention, but choosing the best deposition parameters is still difficult because of several requirements. In this study, the synthesis parameters of CoCrFeNi multi-entropy alloy coatings were optimized using three multi-criteria decision-making techniques: TOPSIS, MOORA, and MARCOS. The impact of criterion importance on the final rankings was evaluated using three weighting schemes: Equal, MEREC, and CRITIC. According to rank stability analysis, alternative A19 continuously obtained the highest rank across all techniques, whereas alternative A16 was consistently found to be the least favorable condition. While MARCOS generated somewhat more variable rankings for mid-performing alternatives, TOPSIS and MOORA showed strong agreement across all weighting schemes, suggesting low sensitivity to weight variation. These trends were further supported by Pearson correlation analysis, which showed somewhat lower correlations with MARCOS but coefficients ≥0.9 for TOPSIS and MOORA variants. In order to speed up performance-driven coating development, the combined approach shows a strong and methodical framework for choosing the best process parameters for HEA coatings. It is also easily adaptable to other material systems.