Crack propagation in silicon nitride ceramics under various temperatures and grain boundary toughness

2015 ◽  
Vol 632 ◽  
pp. 58-61 ◽  
Author(s):  
Sai Wei ◽  
Lukas W. Porz ◽  
Zhipeng Xie ◽  
Bin Liu ◽  
Juan Chen ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Propagation ◽  
Nitride Ceramics

Effect of Oxynitride Grain Boundary Phase on Toughening of Silicon Nitride Ceramics

2006 ◽  
Vol 317-318 ◽  
pp. 649-652 ◽  
Author(s):  
Takafumi Kusunose ◽  
Tohru Sekino ◽  
P.E.D. Mogan ◽  
Koichi Niihara
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Propagation ◽  
Hot Pressing ◽  
Boundary Phase ◽  
Toughening Mechanism ◽  
Nitride Ceramics

The Si3N4/YSiO2N composite in which crystalline YSiO2N was formed as grain boundary phase was fabricated by hot-pressing the mixture of SiO2, Si3N4 and Y2O3. The fracture toughness of this composite was significantly improved, compared to the Si3N4 composites containing Y5Si3O12N or Y2Si3O3N4 as a grain boundary phases. To clarify the toughening mechanism, the microstructure and the crack propagation profiles were observed.

ChemInform Abstract: Dopant Distribution in Grain-Boundary Films in Calcia-Doped Silicon Nitride Ceramics.

ChemInform ◽  
2010 ◽  
Vol 30 (13) ◽  
pp. no-no
Author(s):  
Hui Gu ◽  
Xiaoqing Pan ◽  
Rowland M. Cannon ◽  
Manfred Ruehle
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Dopant Distribution ◽  
Nitride Ceramics ◽  
Doped Silicon ◽  
Boundary Films

High-Resolution Electron Microscopy Observations of Grain-Boundary Films in Silicon Nitride Ceramics

1992 ◽  
Vol 287 ◽  
Author(s):  
H.-J. Kleebe ◽  
M. K. Cinibulk ◽  
I. Tanaka ◽  
J. Bruley ◽  
R. M. Cannon ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silicon Nitride ◽  
High Resolution ◽  
Grain Boundary ◽  
Film Thickness ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Nitride Ceramics ◽  
Boundary Films ◽  
Repulsive Forces

ABSTRACTCharacterization of silicon nitride ceramics by transmission electron microscopy (TEM) provides structural and compositional information on intergranular phases necessary to elucidate the factors that can influence the presence and thickness of grain-boundary films. Different TEM techniques can be used for the detection and determination of intergranular-film thickness, however, the most accurate results are obtained by high-resolution electron microscopy (HREM). HREM studies were applied, in conjunction with analytical electron microscopy, to investigate the correlation between intergranular-phase composition and film thickness. Statistical analyses of a number of grain-boundary films provided experimental verification of a theoretical equilibrium film thickness. Model experiments on a high-purity Si3N4 material, doped with low amounts of Ca, suggest the presence of two repulsive forces, a steric force and a force produced by an electrical double layer, that may act to balance the attractive van der Waals force necessary to establish an equilibrium film thickness.

High-strength silicon nitride ceramics obtained by grain-boundary crystallization

1991 ◽  
Vol 26 (20) ◽  
pp. 5513-5516 ◽  
Author(s):  
K. Komeya ◽  
M. Komatsu ◽  
T. Kameda ◽  
Y. Goto ◽  
A. Tsuge
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
High Strength ◽  
Nitride Ceramics

Silicon Nitride Ceramics with Sodium Ion Conductive Grain Boundary Phase

2003 ◽  
Vol 18 (12) ◽  
pp. 2752-2755 ◽  
Author(s):  
Hirokazu Kawaoka ◽  
Tohru Sekino ◽  
Takafumi Kusunose ◽  
Koichi Niihara
Keyword(s):  
Electrical Conductivity ◽  
Silicon Nitride ◽  
Ionic Conductivity ◽  
Grain Boundary ◽  
Sodium Ion ◽  
Boundary Phase ◽  
Structural Ceramics ◽  
Silicon Nitride Ceramic ◽  
Nitride Ceramics ◽  
Conductive Particles

Sodium ion-conductive silicon nitride ceramic with Na2O–Al2O3–SiO2 glass as the grain boundary phase was fabricated by adding Na2CO3, Al2O3, and SiO2 as sintering additives. The electrical conductivity was two and four orders of magnitude higher than that of Si3N4 ceramic with Y2O3 and Al2O3 additives at 100 and 1000°C, respectively. This result clearly indicates that ionic conductivity can be provided to insulating structural ceramics by modification of the grain boundary phase without dispersion of conductive particles.

Microstructure and microanalysis of silicon nitride ceramics in the Y-Si-Al-O-N and Y-Si-O-N systems

1990 ◽  
Vol 48 (4) ◽  
pp. 1072-1073
Author(s):  
Michael K. Cinibulk
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Grain Boundary Sliding ◽  
Liquid Phase Sintering ◽  
Boundary Phase ◽  
Full Density ◽  
High Temperature Strength ◽  
Transmission Electron ◽  
Structural Applications ◽  
Nitride Ceramics

Silicon nitride ceramics are among the leading candidate materials for use in structural applications at high temperatures. Due to the highly covalent nature of the Si-N bond and therefore low self-diffusivity, processing Si3N4 to full density requires the use of additives to provide a medium for liquid-phase sintering. When exposed to temperatures above ∼1000°C the resulting amorphous grain-boundary phases soften, leading to grain-boundary sliding and the eventual failure of the ceramic. The objectives of this work were to modify the grain-boundary phase composition and then attempt to devitrify the resulting intergranular phase to a refractory crystalline phase, producing a sintered Si3N4 with improved high-temperature strength and oxidation resistance. Transmission electron microscopy (TEM) and energy-dispersive x-ray spectroscopy (EDS) were used to characterize these materials. This paper describes these results.

Compositions and Thicknesses of Grain Boundary Films in Ca-Doped Silicon Nitride Ceramics

1994 ◽  
pp. 275-289 ◽  
Author(s):  
I. Tanaka ◽  
J. Bruley ◽  
H. Gu ◽  
M. J. Hoffmann ◽  
H.-J. Kleebe ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Nitride Ceramics ◽  
Doped Silicon ◽  
Boundary Films
Sign in / Sign up

Export Citation Format

Share Document