Sm. Allameh et al., THE ROLE OF INTERFACIAL ENERGY IN CRYSTALLITE REORIENTATION BY TWINNING, Acta metallurgica et materialia, 41(10), 1993, pp. 2887-2896
Based on the results of annealing experiments, inside and outside the
electron microscope, a new mechanism has been found for the reorientat
ion of particles on a monocrystalline substrate. Silver particles sint
ered on the (110) surface of a nickel substrate such that (110)[111BAR
]Ag parallel-to (110)[111BAR]Ni were reoriented by the nucleation and
growth of annealing twins. All of the growing twins were of one varian
t. Twins of other orientations did not nucleate, and in particles that
contained them before sintering, they did not grow. The driving force
for twinning comes from the reduction in the particle/substrate inter
facial free energy. These observations are consistent with the hierarc
hy of Ag/Ni interfacial energies as calculated with the embedded-atom
method. The ramifications of the results are discussed for annealing t
wins and for epitaxy.