Optimization for drilling process of metal-composite aeronautical structures

Abstract Metal-composite laminates and joints are applied in aircraft manufacturing maintenance (repairing) using aluminum alloys (AA) glass fiber-reinforced polymer (GFRP). In these applications, drilling has a prominent place due to its vast application aeronautical structures’ mechanical joints. Thus, this study presents the influence of uncoated carbide drills (85C, 86C, H10N), cutting speeds ( v c = 20, 40, 60 m min ?1 ), feed rates f 0.05, 0.15, 0.25 mm rev ) on delamination factor, thrust force F t {F}_{\text{t}} burr formation dry metal-composite (AA2024/GFRP/AA2024). Experiments were performed, analyzed, optimized Box–Behnken statistical design. Microscopic digital images for evaluation, piezoelectric dynamometer acquisition, analysis considered. The major finding was that during depends significantly rate. Another significant factor drill type (combined or not with rate). fact, it verified rate most parameters while relevant force. speed did affect at exit ( da S stretchy="false">) \hspace{.25em}({F}_{{\text{da}}_{\text{S}}}) . However, combination × entrance E \text{ }({F}_{{\text{da}}_{\text{E}}}) Based input parameters, they presented lower values factors = 1.18 {F}_{{\text{da}}_{\text{E}}}=1.18 1.33 {F}_{{\text{da}}_{\text{S}}}=\hspace{.25em}1.33 67.3 width=".5em" N {F}_{\text{t}}=67.3\hspace{.5em}\text{N} ). These obtained by 85C-tool, 0.05 rate, 20 speed. burrs hole output AA2024 considered unsatisfactory specific condition, which implies additional investigation.