Nanomechanical Characterization of the Deformation Response of Orthotropic Ti–6Al–4V

The nanoindentation-induced mechanical deformation response is applied to
identify the orthotropic elastic moduli using the Delafargue and Ulm method as
well as to validate the asymmetri c orthotropic CPB06 nonlinear plasticity model
required in simulations of nonuniform macroscopic mechanical response of the
Ti–6Al–4V alloy. Scanning electron microscope (SEM) technique allows to select
the maximum penetration depth for the indentation in the deformed alpha phase
and alpha–beta interphase, α and α/β, respectively. The apparent macrome-
chanical response can be successfully derived from several residual imprints
conducted at micro- and/or submicrometric length scale and distributed
throughout samples of the investigated bulk alloy, as demonstrated by correlation
with nite element simulations based on the orthotropic elastoplastic model. The
accurate numerical response obtained validates the material model and the
Delafargue and Ulm approach, opening a window for next generation identi-
cation methods of macromechanical plasticity models with hybrid experimental–
numerical method based on instrumented indentation and the use of SEM
technique.