Hole Quality Assessment During Drilling of Carbon‐Kevlar Hybrid Textile Composite Considering Matrix and Tool Geometry Effect

ABSTRACT In lightweight engineering applications, carbon–Kevlar hybrid textile composites are increasingly employed, yet drilling‐induced damage is a critical challenge because of their heterogeneous fiber architecture, differing failure mechanisms, and matrix‐dependent behavior. Till now, the combined effect of matrix type, tool geometry, and drilling parameters on hole quality of carbon‐Kevlar hybrid textile composites has not yet been properly analyzed. In the present study, two matrices (polypropylene and epoxy), two drills (twist and brad spur), and two drilling parameters (feed rate and spindle speed) were considered. For both drills, the drilling outcomes of the polypropylene composite show reduced thermal generation, force, damage evolution, and surface irregularity. With the brad spur drill, the polypropylene composite shows lower values than the epoxy composite for temperature (56.95%), thrust force (48.55%), delamination (54.19%), and surface roughness (36.55%). With the twist drill, the reductions are 54.98%, 47.58%, 41.92%, and 30.46%, respectively. Comparing tools, the brad spur yields lower temperature, thrust force, delamination, and roughness than the twist by 26.01%, 33.29%, 30.31%, and 23.80% for the polypropylene composite, and 22.61%, 32.03%, 11.64%, and 16.48% for the epoxy composite.