TY - GEN
T1 - Crack healing of nano-Ni/Al2O3 hybrid materials via high-temperature oxidation
AU - Maruoka, Daisuke
AU - Nanko, Makoto
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2011
Y1 - 2011
N2 - Crack-healing effectiveness was investigated on 5 vol% nano-Ni dispersed Al2O3 hybrid materials. Influence of the Y or Si doping or SiC co-dispersion was also studied on the crack healing behavior. Cracks were introduced by a Vickers indentation to be a crack length of approximately 60 μm. Cracks of nano-Ni/Al2O3 were completely disappeared, for example, by oxidation at 1200°C for 6 h in air, Y/Si doped one and SiC co-dispersed one have similar performance of crack disappearance. Bending strength of crack-disappeared samples showed about 550 MPa and was comparable or improved with that of as-sintered one. Mechanism of crack healing was considered as filling up of cracks by NiAl2O4 oxidation product which is developed by outward diffusion of cations at grain boundary of Al2O3matrix. Nano-Ni/Al2O 3 with Y or Si doping or SiC co-dispersion are realized to have crack-healing effectiveness with improved high-temperature oxidation resistance.
AB - Crack-healing effectiveness was investigated on 5 vol% nano-Ni dispersed Al2O3 hybrid materials. Influence of the Y or Si doping or SiC co-dispersion was also studied on the crack healing behavior. Cracks were introduced by a Vickers indentation to be a crack length of approximately 60 μm. Cracks of nano-Ni/Al2O3 were completely disappeared, for example, by oxidation at 1200°C for 6 h in air, Y/Si doped one and SiC co-dispersed one have similar performance of crack disappearance. Bending strength of crack-disappeared samples showed about 550 MPa and was comparable or improved with that of as-sintered one. Mechanism of crack healing was considered as filling up of cracks by NiAl2O4 oxidation product which is developed by outward diffusion of cations at grain boundary of Al2O3matrix. Nano-Ni/Al2O 3 with Y or Si doping or SiC co-dispersion are realized to have crack-healing effectiveness with improved high-temperature oxidation resistance.
KW - Bending strength
KW - Crack healing
KW - Grain boundary diffusion
KW - High temperature oxidation resistance
KW - Nanocomposite
KW - Pulsed electric current sintering
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U2 - 10.4028/www.scientific.net/MSF.696.378
DO - 10.4028/www.scientific.net/MSF.696.378
M3 - Conference contribution
AN - SCOPUS:80053485051
SN - 9783037852354
T3 - Materials Science Forum
SP - 378
EP - 383
BT - High-Temperature Oxidation and Corrosion 2010, ISHOC-10
PB - Trans Tech Publications Ltd
T2 - 3rd International Symposium on High-Temperature Oxidation and Corrosion, ISHOC-10
Y2 - 8 November 2010 through 11 November 2010
ER -