Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Microstructure development and properties of novel Ba-doped phase Sialon ceramics
AU - Basu, B.
AU - Lewis, M.H.
AU - Smith, M.E.
AU - Bunyard, M.
AU - Kemp, T.
PY - 2006
Y1 - 2006
N2 - Herein, we report the microstructure and properties of the newly developed near monophasic S-Sialon ceramic, based on the composition of Ba2Si12-xAlxO2+xN16-x (x = 20.2). Appropriate amount of the precursor powders (BaCO3, α-Si3N4, AlN, Al2O3) with a targeted composition of BaAlSi5O2N7 was ball milled and hot pressed to full density in the temperature range of 1600-1750 °C for 2 h in nitrogen atmosphere. Extensive transmission electron microscopy (TEM) study has been conducted to understand the microstructure development and characterise the various morphological features in hot pressed S-Sialon. The sintering mechanism is based on the liquid phase sintering route, which involves the formation of a Ba-Al silicate liquid (<5%) with dissolved nitrogen at intergranular pockets. The experimental observation suggests that the S-phase crystallises in elongated platelet morphology with preferred growth parallel to the orthorhombic 'c' axis and primary facet planes parallel to (1 0 0) and (0 1 0). The Ba-S-phase ceramic has an acoustically measured Young modulus of 210-230 GPa, a hardness of 13 GPa and a fracture toughness of 4 MPa m1/2, little lower than typical of a ceramic with morphologically anisotropic grains contributing to bridging and pullout mechanisms. © 2006 Elsevier Ltd. All rights reserved.
AB - Herein, we report the microstructure and properties of the newly developed near monophasic S-Sialon ceramic, based on the composition of Ba2Si12-xAlxO2+xN16-x (x = 20.2). Appropriate amount of the precursor powders (BaCO3, α-Si3N4, AlN, Al2O3) with a targeted composition of BaAlSi5O2N7 was ball milled and hot pressed to full density in the temperature range of 1600-1750 °C for 2 h in nitrogen atmosphere. Extensive transmission electron microscopy (TEM) study has been conducted to understand the microstructure development and characterise the various morphological features in hot pressed S-Sialon. The sintering mechanism is based on the liquid phase sintering route, which involves the formation of a Ba-Al silicate liquid (<5%) with dissolved nitrogen at intergranular pockets. The experimental observation suggests that the S-phase crystallises in elongated platelet morphology with preferred growth parallel to the orthorhombic 'c' axis and primary facet planes parallel to (1 0 0) and (0 1 0). The Ba-S-phase ceramic has an acoustically measured Young modulus of 210-230 GPa, a hardness of 13 GPa and a fracture toughness of 4 MPa m1/2, little lower than typical of a ceramic with morphologically anisotropic grains contributing to bridging and pullout mechanisms. © 2006 Elsevier Ltd. All rights reserved.
KW - Electron microscopy
KW - Mechanical Properties
KW - Microstructure
KW - S-Sialon
KW - Sintering
KW - Anisotropy
KW - Barium compounds
KW - Crystal growth
KW - Crystal microstructure
KW - Crystallization
KW - Elastic moduli
KW - Fracture toughness
KW - Hardness
KW - Morphology
KW - Transmission electron microscopy
KW - Facet planes
KW - Liquid phase sentering
KW - Precursor powders
KW - Sialon ceramic
KW - Ceramic materials
U2 - 10.1016/j.jeurceramsoc.2006.01.004
DO - 10.1016/j.jeurceramsoc.2006.01.004
M3 - Journal article
VL - 26
SP - 3919
EP - 3924
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
SN - 0955-2219
IS - 16
ER -