Multi-Criteria Evaluation of Brake Disc Materials Using BWM-TOPSIS Linear Programming

The selection of the best all-around material for brake discs remains a challenging engineering problem due to the conflicting requirements for wear resistance, thermal stability, mechanical strength, and manufacturability. To address this multi-criteria challenge, this study proposes an integrated decision-making framework combining the index of Item-Objective Congruence (IOC), the Best-Worst Method (BWM), and the Technique for Order Preference by Similarity to Ideal Solution Linear Programming (TOPSIS-LP) approach. The IOC was employed to validate the relevance of six evaluation criteria based on input from five domain experts, while BWM derived weights for these criteria. TOPSIS-LP was then used to rank five material alternatives, including gray cast iron, steel alloy, Aluminum Metal Matrix Composite (Al-MMC), Carbon-Carbon/Carbon-Silicon Carbide Composite (C-C/SiC), and Ceramic-Based Composites (CMC), through linear optimization of the weighted decision matrix. The results indicated that the CMC achieved the highest performance with a relative closeness coefficient CCi of 0.7629, followed by C-C/SiC and Al-MMC, while a four-scenario sensitivity analysis confirmed perfect rank stability (Spearman's rank correlation: ρs = 1.00) under ±20% weight variations. Overall, the findings indicate that advanced ceramic and composite materials outperform conventional metals in tribological and thermal performance, while the proposed IOC-BWM-TOPSIS-LP framework demonstrates strong robustness, interpretability, and applicability to complex engineering material selection problems.