Oxidation Behavior and Mechanical Property of Si<sub>3</sub>N<sub>4</sub> Ceramics with Rare Earth Oxide Addition

The effects of rare earth oxides (Lu2O3 and La2O3) on the property, microstructure and oxidation behavior of hot-pressing sintered Si3N4 ceramics were investigated. The silicon nitride ceramics with Lu2O3 and La2O3 as addition have been fabricated by hot-pressed at 1800°C for 1h under a pressure of 25MPa. Oxidation test was carried out at 1400°C in air for 100 hours. Mechanical properties, SEM and XRD were measured before and after oxidation. The results showed that Si3N4 ceramics doped Lu2O3 had good microstructure and mechanical properties than those doped La2O3. Oxidation test showed a parabolic weight gain with oxidation time at 1400°C in air and the oxidation products of the ceramics were SiO2, Re2Si2O7 and Re2SiO5 confirmed by XRD and EDS. The rate-controlling step was the diffusion of ion. The samples doped Lu2O3 showed superior oxidation resistance to those doped La2O3.

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Effects of rare earth oxide addition on NdFeB magnets.

Journal of the Magnetics Society of Japan ◽

10.3379/jmsjmag.11.235 ◽

1987 ◽

Vol 11 (2) ◽

pp. 235-238 ◽

Cited By ~ 9

Author(s):

K. Ohashi ◽

T. Yokoyama ◽

Y. Tawara

Keyword(s):

Rare Earth ◽

Rare Earth Oxide ◽

Ndfeb Magnets ◽

Oxide Addition

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Effect of Processing Technique on Microstructure and Oxidation Behavior of Rare Earth Oxide Dispersion Containing Steels

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.189-191.322 ◽

2001 ◽

Vol 189-191 ◽

pp. 322-327 ◽

Cited By ~ 3

Author(s):

M.F. Pillis ◽

Lalgudi Venkataraman Ramanathan

Keyword(s):

Rare Earth ◽

Oxidation Behavior ◽

Rare Earth Oxide ◽

Processing Technique ◽

Oxide Dispersion

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Oxidation Behavior Research of the SiC/B4C Multiphase Ceramics

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.727-728.288 ◽

2015 ◽

Vol 727-728 ◽

pp. 288-291 ◽

Cited By ~ 1

Author(s):

Yun Long Zhang ◽

Xiao Gang Song ◽

Guo Jing Li ◽

Yu Min Zhang

Keyword(s):

Rare Earth ◽

Oxidation Behavior ◽

Rare Earth Oxide ◽

Eutectic Phase ◽

Oxidation Time ◽

Pressureless Sintering ◽

Micro Structure ◽

Phase Constitution ◽

Sintering Additives ◽

Multiphase Ceramics

Inthis investigation, the rare-earth oxide Yb2O3 combined with Al2O3served as sintering additives and SiC and B4C powder were applied to fabricate SiC/B4C multiphase ceramics composites by pressureless sintering. The results proved thatcombination of Al2O3 and Yb2O3 sinter additives were effective fordensification of SiC/B4C composites. The influence of oxidation time onthe phase constitution, micro-structure and oxidation behavior of SiC/B4C composites was investigated.Theformation of eutectic phase Yb2Si2O7 phase waswrapped on the SiC surface and it reduced further oxidation of SiC particles.The oxidation kineticcurves followed a parabolic rule.

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