Process parameter auto-adaptation strategy for one-up drilling of CFRP/aluminium hybrid stack

The aerospace sector is looking for lighter, more robust, and less fuel-consuming aircraft by using advanced lightweight materials. Fibre-reinforced polymers and lightweight alloys are pivotal to this aim, owing to their favourable strength-to-weight ratio and mechanical properties. Therefore, assembling hybrid stacks of these materials offers customisation opportunities to optimise performance and structural integrity. This research explores one-up drilling techniques for hybrid stacks of carbon fibre-reinforced polymer (CFRP) laminates and aluminium alloy sheets, which are essential in the fabrication of advanced aircraft structures. The experimental procedure consists of first drilling individual materials separately to optimise the process parameters for each material and then drilling a hybrid stack configuration (CFRP/AA7075-T6) with an innovative approach using spindle active power monitoring to implement a self-adapting strategy of process parameters at the interface between the two materials. This flexible methodology offers a practical solution for streamlining the drilling process in aerospace applications.