Grain boundary strengthening in alumina by rare earth impurities.
Impurity doping often alters or improves the properties of materials. In alumina, grain boundaries play a key role in deformation mechanisms, particularly in the phenomenon of grain boundary sliding during creep at high temperatures. We elucidated the atomic-scale structure in alumina grain boundaries and its relationship to the suppression of creep upon doping with yttrium by using atomic resolution microscopy and high-precision calculations. We find that the yttrium segregates to very localized regions along the grain boundary and alters the local bonding environment, thereby strengthening the boundary against mechanical creep.
Buban
J P
JP
Institute of Engineering Innovation, University of Tokyo, 2-11-16, Yayoi, Bunkyo, Tokyo 113-8656, Japan.
Matsunaga
K
K
Chen
J
J
Shibata
N
N
Ching
W Y
WY
Yamamoto
T
T
Ikuhara
Y
Y