  Functionally Graded Material (FGM) is a type of advanced material consisting
of two (or more) distinct substances with a constantly changing composition
profile. FGM technologies have moved from their traditional use to advanced
micro and nanoscale electronics and energy conversion systems along with the
advent of nanotechnology. MD simulations are used in this analysis to examine
the effect of compressive load on Ag-Au FGM and Core-shell nanospheres. The
plasticity process is often started by the nucleation of partial dislocations
from the contact surfaces, and these dislocations spread towards the
nanosphere's center. Also, we have found the formation of pyramidal-shaped
partial dislocations on the pseudo-plastic regime. For a given wt% range of Ag
in Au, Coreshell nanospheres have stronger mechanical strength than FGM
nanospheres, and we have also observed two distinct patterns in ultimate stress
variation for FGM and Coreshell nanospheres. The dislocation analysis suggests
a correlation between this stress variation and the Shockley & Hirth partial
dislocation density.
