Homogeneous and Localized Deformation in Poly(Methyl Methacrylate) Nanocutting

Nanoscale manufacturing imposes demands on prediction of cutting processes on small scales. Predictive modeling schemes based on the underlying physical mechanisms could potentially be more generally applicable in manufacturing. In this work, the experimental and numerical studies on polymethyl methacrylate (PMMA) nanocutting are reported. The cutting experiments were performed on an ultramicrotome instrumented with piezoelectric transducers to measure the cutting forces on cutting down to about 60 nm thickness. Using atomic force microscopy, the surface damage was identified as shear yield bands triggered by adiabatic heating. A suitable physical model including these observed phenomena made it possible to link the processing conditions with the onset of damage, i.e., the transition between a high-quality transparent surface and a damaged uneven surface. Finite element analysis was carried out to investigate the deformation modes of PMMA under different cutting conditions and to predict the formation of the undesired shear bands. From an engineering perspective, such an approach could be potentially useful in improving manufacturing control.