Nanoscale plastic deformation and fracture of polymers studied by in situ nanoindentation in a transmission electron microscope

摘要

Nanoscale plasticity and fracture of polymers were studied by in situ nanoindentation in a transmission electron microscope. The indentation-induced plasticity during loading and the significant recovery of the deformed polymer upon unloading provide insight into the nanoscale viscoelastic and plastic behavior. Crack initiation and growth from a preexisting surface nanodefect due to adjacent nanoindentation was found to lead to localized delamination. The in situ observations of this study provide information for the evolution of nanoscale viscoelastic-plastic deformation and fracture (delamination) processes at polymer surfaces during the loading and unloading phases of a nanoindentation cycle.