  We present a high-throughput nanoindentation study of in-situ bending effects
on incipient plastic deformation behavior of polycrystalline and
single-crystalline pure aluminum and pure copper at ultra-nano depths (<200nm).
We find that hardness displays a statistically inverse dependence on in-plane
stress for indentation depths smaller than 10nm, and the dependence disappears
for larger indentation depths. In addition, plastic noise in the
nanoindentation force and displacement displays statistically robust noise
features, independently of applied stresses. Our experimental results suggest
the existence of a regime in FCC crystals where ultra-nano hardness is
sensitive to residual applied stresses, but plasticity pop-in noise is
insensitive to it.
