Influence of Drilling Strategy and Cutting Parameters on Selected Aspects of the Single-Shot Drilling of CFRP/AISI 316L Steel Stacks

Drilling is often used to create holes in CFRP/AISI 316L hybrid stacks to facilitate the assembly process. Due to the non-uniform properties and difficult machinability of Cr-Ni-Mo AISI 316L steel, drilling CFRP/AISI 316L stacks poses significant challenges in manufacturing processes. This paper aims to evaluate the tool–workpiece interaction and the effect of the drilling strategy on the technological aspects of drilling CFRP/AISI 316L stacks. The experimental results show that cutting parameters have a significant impact on the drilling performance of CFRP/AISI 316L stacks. The AISI 316L → CFRP drilling strategy provides lower hole surface roughness with less burr formation in the AISI 316L layer, while the CFRP → AISI 316L drilling strategy is preferred in terms of minimizing delamination damage. The high temperature generated during drilling of the AISI 316L layer directly affects the hole surface quality in the CFRP layer and the phenomena occurring in the interlayer of the stack materials. The experimental results presented in this work allowed us to formulate several recommendations regarding the selection of cutting strategy and cutting parameters when drilling CFRP/AISI 316L hybrid stacks.