Optimizing Process Parameters in Drilling of CFRP Laminates: A Combined MOORA-TOPSIS-VIKOR Approach

Carbon fiber-reinforced plastics (CFRP) have excelled in mechanical performance, replacing metals in structural design. However, their challenging machinability especially in drilling for assembly necessitates careful optimization of process parameters for mass production efficiency and waste reduction. This study explores the optimization of the drilling process for carbon fiber-reinforced composite laminates with a stacking sequence of [0/-45/90/45]2s. Using the tungsten carbide twist drills, experiments were conducted on quasi-isotropic CFRP laminates with a thickness of 10 mm. The drilling process parameters, including spindle speed and feed rate, were systematically varied to investigate their influence on drilled hole defects. A three-axis CNC milling center equipped with a piezoelectric dynamometer captured thrust force and drilling torque signals, forming the basis of the experimental methodology. The research employs multi-criteria decision-making techniques, such as MOORA, TOPSIS, and VIKOR, to identify the optimal combination of parameters for minimizing defects and enhancing drilling efficiency. In this study, the synergy of these multi-criteria decision-making techniques establishes a novel framework, demonstrating their efficacy in addressing the challenges associated with CFRP laminate drilling. Quantitatively, the optimized drilling parameters, combination of high speed, low feed rate, and low point angle tool resulted in a remarkable 20% reduction in top surface delamination defects, coupled with a 15% improvement in circularity error and surface roughness, underscoring the effectiveness of the proposed optimization approach in enhancing the quality of drilled holes in CFRP laminates. A comparative assessment of the results reveals notable achievements, including a significant correlation of 0.986 between the TOPSIS and VIKOR methods.