Effect of tool size on the cutting of aluminum film with micrometer-level thickness

Cutting aluminum films with micrometer-level thickness requires a full understanding of the mixed effect due to bending, buckling, and fracture. These three deformation patterns have a strong relationship with the tool size. In this study, we present experimental, numerical, and theoretical studies of the tool size effect on a fracture. Using the energy analysis during a cut, we first build up a cutting force model that takes both the tool size and film thickness into account. The proposed model differs from previous models that used the ratio of size to thickness as the only factor. Our results first show that tool size affects fracture morphology. Films cut with large tools fail in the form of sequenced concertina tears, while films cut with small tools fail in the form of curling flaps. Furthermore, the transition of the two failure modes is theoretically presented with the critical value being obtained by the cutting force model proposed. Additionally, we find that when predicting the cutting force of aluminum films with micrometer-level thickness, the effect of fracture energy cannot be neglected. Increasing film thickness will decrease the effect of fracture energy on cutting force.