One-shot drilling process for thin CFRP/Aluminium alloys stacks

The aerospace industry pursues lighter, stronger, and more fuel-efficient aircraft, relying on lightweight materials. This study investigates one-shot drilling of thin hybrid stacks, including carbon fiber-reinforced polymer (CFRP, 2.2 mm thick), and aluminum alloys (Al2024-T3, 1.6 mm thick, and Al7075-T6, 1.0 mm thick), crucial in modern aircraft structures. The challenge of thin materials lies in their reduced flexural stiffness, which significantly impacts the quality of the final hole and the effects of the process parameters on torque and thrust force. The experimental approach involves drilling each material separately to analyze thrust force, torque, and hole quality, then comparing outcomes with one-shot drilling in thin hybrid stacks. The results highlight that thin hybrid stacks are challenging to drill because their reduced flexural stiffness significantly impacts the final hole quality and the effects of the process parameters on torque and thrust force differently from what typically occurs for the drilling of conventional hybrid stacks.