TY - JOUR
T1 - Interfacial energies and mass transport in the Ni(Al)-Al2O 3 system: The implication of very low oxygen activities
T2 - The implication of very low oxygen activities
AU - Ni, Na
AU - Kaufmann, Yaron
AU - Kaplan, Wayne D.
AU - Saiz, Eduardo
N1 - Funding Information: The authors would like to thank the EPSRC Science and Innovation grant Building New Capability in Structural Ceramics (EP/F033605/1). Na Ni would also like to acknowledge the EPSRC postdoctoral prize fellowship (under EP/J500239/1) for supporting the work. Dr. Tzipi Cohen-Hyams at Department Materials Science & Engineering – Technion is gratefully acknowledged for the assistance in preparing the TEM standard sample of Al 3 Ni.
PY - 2014/2
Y1 - 2014/2
N2 - Adhesion and capillary-driven mass transport at ceramic-metal interfaces play a very important role in the performance and durability of materials for many applications, and the influence of the oxygen activity is a critical issue. This work systematically investigates the variation of interfacial energies and atomic transport mechanisms at metal-oxide interfaces at very low oxygen activities by bonding Ni-Al alloys and pure polycrystalline alumina under controlled conditions in sessile drop experiments. The angles and the evolution of the grain boundary grooves were analyzed by scanning electron microscopy, atomic force microscopy and focused ion beam milling to calculate the interfacial and grain boundary energies and the transport rates at the metal-Al2O3 interface. In parallel, high-resolution structural and chemical analysis of selected grain boundaries was performed using advanced transmission electron microscopy. Our results confirm that all the interfacial energies (metal-Al2O3, Al 2O3 surface and grain boundary energy) are smaller at reduced p(O2) than those of stoichiometric interfaces. The atomic transport at the metal-Al2O3 interface was found to decrease initially with decreasing p(O2) but increased significantly with a further decrease in the oxygen activity. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
AB - Adhesion and capillary-driven mass transport at ceramic-metal interfaces play a very important role in the performance and durability of materials for many applications, and the influence of the oxygen activity is a critical issue. This work systematically investigates the variation of interfacial energies and atomic transport mechanisms at metal-oxide interfaces at very low oxygen activities by bonding Ni-Al alloys and pure polycrystalline alumina under controlled conditions in sessile drop experiments. The angles and the evolution of the grain boundary grooves were analyzed by scanning electron microscopy, atomic force microscopy and focused ion beam milling to calculate the interfacial and grain boundary energies and the transport rates at the metal-Al2O3 interface. In parallel, high-resolution structural and chemical analysis of selected grain boundaries was performed using advanced transmission electron microscopy. Our results confirm that all the interfacial energies (metal-Al2O3, Al 2O3 surface and grain boundary energy) are smaller at reduced p(O2) than those of stoichiometric interfaces. The atomic transport at the metal-Al2O3 interface was found to decrease initially with decreasing p(O2) but increased significantly with a further decrease in the oxygen activity. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
KW - Grain boundary energy
KW - Grain boundary structure
KW - Interface energy
KW - Metal-ceramic interfaces
KW - Transmission electron microscopy (TEM)
UR - https://www.mendeley.com/catalogue/a8acef88-db2e-3c36-9c2c-225f3fd1d2b3/
UR - http://www.scopus.com/inward/record.url?scp=84892368924&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2013.10.041
DO - 10.1016/j.actamat.2013.10.041
M3 - Article
SN - 1359-6454
VL - 64
SP - 282
EP - 296
JO - Acta Materialia
JF - Acta Materialia
ER -