Faceting,
Grain Growth, and Crack Healing in Alumina
Pankaj Rajak
Rajiv K. Kalia
Aiichiro Nakano
Priya Vashishta
10.1021/acsnano.8b02484.s001
https://acs.figshare.com/articles/journal_contribution/Faceting_Grain_Growth_and_Crack_Healing_in_Alumina/6942998
Reactive molecular dynamics simulations
are performed to study
self-healing of cracks in Al<sub>2</sub>O<sub>3</sub> containing core/shell
SiC/SiO<sub>2</sub> nanoparticles. These simulations are carried out
in a precracked Al<sub>2</sub>O<sub>3</sub> under mode 1 strain at
1426 °C. The nanoparticles are embedded ahead of the precrack
in the Al<sub>2</sub>O<sub>3</sub> matrix. When the crack begins to
propagate at a strain of 2%, the nanoparticles closest to the advancing
crack distort to create nanochannels through which silica flows toward
the crack and stops its growth. At this strain, the Al<sub>2</sub>O<sub>3</sub> matrix at the interface of SiC/SiO<sub>2</sub> nanoparticles
forms facets along the prismatic (A) ⟨2̅110⟩ and
prismatic (M) ⟨1̅010⟩ planes. These facets act
as nucleation sites for the growth of multiple secondary amorphous
grains in the Al<sub>2</sub>O<sub>3</sub> matrix. These grains grow
with an increase in the applied strain. Voids and nanocracks form
in the grain boundaries but are again healed by diffusion of silica
from the nanoparticles.
2018-08-03 00:00:00
precracked Al 2 O 3
study self-healing
nanoparticle
Al 2 O 3
Al 2 O 3 matrix
Grain Growth
prismatic
SiC
nanocracks form
Alumina Reactive
mode 1 strain
grain boundaries
nucleation sites
Crack Healing
dynamics simulations
silica flows
facets act