Optimization and alternative image processing approach for the comprehensive assessment of delamination and uncut fiber in drilling fiber metal laminate

In this study, hole exit delamination and uncut fiber (UCF) formation in the drilling of carbon fiber-reinforced aluminum laminates (CARALL) were investigated. The adjusted delamination factor (F-da) was used to assess delamination. The experiments were carried out using a brad spur drill (Tool 1), a twist drill (Tool 2), and a dagger drill (Tool 3) tool. A multi-mapped image processing model (MMIPM) was developed for an advanced and comprehensive delamination assessment in images by evaluating F-da and UCF parameters. In order to provide more information about the preferential orientation of delamination, in addition to F-da, conventional delamination factor (F-d) and minimum delamination factor (F-dmin) were calculated and a comparison of all delamination approaches was performed. Furthermore, the PROMETHEE-GAIA method was used to perform multi-objective optimization of F-da and UCF. The minimum F-da and UCF values were achieved with the twist drill (Tool 2). Vc = 118 m/min and f = 0.156 mm/rev were optimal conditions for minimum F-da and UCF.