Deformation Rate Effect And Near Surface Damage Evolution - A Nanomechanical Probing Study
Free (open access)
K B Yoder, Y Katz & W W Gerberich
Mechanical response of small volumes by contact testing becomes a key issue both fundamentally and/or for practical applications. Phenomenological studies by nanoidentation and continuous micro scratch technique in different solids eventually reveal specific deformation behavior and failure trends. Mostly such differences can be attributed to the material constitutive properties and to the loading conditions. Nevertheless, the current study mainly in glassy polymers of small volume behavior by nanomechanical probing introduces highly complex combination. These in terms of inhomogeneous deformation, characteristic damage patterns, crack density variations and fracture criteria aspects. The current objective is to develop further insights into damage evolution by including also the critical variable of the deformation rate. Experimentally, nanoidentation and continuous micro scratch techniques were applied at ambient temperatures with tip velocities spanning four orders of magnitude, The study has revealed that in some circumstances even the self-organized damage features could be illuminated with emphasis to the local strain rate aspects.