Fracture Behavior of a Silicon Nitride Ceramic Containing a High Temperature Ductile Phase

1992 ◽  
pp. 407-425
Author(s):  
Roger L. K. Matsumoto ◽  
Julie W. Pier
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Fracture Behavior ◽  
Ductile Phase ◽  
Silicon Nitride Ceramic

Dependence of fracture stress on applied stress rate in a Yb2O3–SiO2-doped hot-pressed silicon nitride ceramic

2001 ◽  
Vol 16 (11) ◽  
pp. 3254-3261 ◽  
Author(s):  
Shuqi Guo ◽  
Naoto Hirosaki ◽  
Yoshinobu Yamamoto ◽  
Toshiyuki Nishimura ◽  
Mamoru Mitomo
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Crack Growth ◽  
Applied Stress ◽  
Fracture Stress ◽  
Fracture Behavior ◽  
Slow Crack Growth ◽  
Silicon Nitride Ceramic ◽  
Temperature Fracture ◽  
Stressing Rate

High-temperature fracture behavior of a Yb2O3–SiO2–doped hot-pressed silicon nitride (Si3N4) ceramic was investigated in four-point flexure between 1000 and 1500 °C at five crosshead speeds, using the specimens precracked with three indentation loads. Above 1000 °C, a temperature and stressing rate dependence of fracture stress was seen. At 1200 °C the fracture stress of the precracked specimens increased with decreasing stressing rates due to a toughening effect, the absence of slow crack growth (SCG). However, at 1400 and 1500 °C the fracture stress decreased with decreasing stressing rate. In particular, this dependence was stronger at 1500 °C than at 1400 °C. The SCG was observed only in the specimens precracked with indentation loads of 98 and 196 N. This crack extended with increasing test temperature and/or decreasing stressing rate. The dependence of fracture stress on stressing rate was attributed to a SCG behavior at higher temperatures.

scholarly journals Fracture Behavior of a Silicon Nitride Ceramic under Mixed-Mode Fracture Condition

1993 ◽  
Vol 101 (1170) ◽  
pp. 240-243 ◽  
Author(s):  
Takashi ONO ◽  
Takeshi TAKENOSHITA ◽  
Hiroshi UCHIMURA ◽  
Masaki KAJI
Keyword(s):  
Silicon Nitride ◽  
Mixed Mode ◽  
Fracture Behavior ◽  
Mixed Mode Fracture ◽  
Silicon Nitride Ceramic ◽  
Mode Fracture ◽  
Fracture Condition

Research on the metamorphic layer of silicon nitride ceramic under high temperature based on molecular dynamics

2020 ◽  
Vol 109 (5-6) ◽  
pp. 1249-1260 ◽  
Author(s):  
Jinmei Yao ◽  
Yuhou Wu ◽  
Jian Sun ◽  
Ying Xu ◽  
He Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Silicon Nitride ◽  
Silicon Nitride Ceramic

High-temperature slow crack growth of an Yb2O3–SiO2-doped hot-pressed silicon nitride ceramic

2003 ◽  
Vol 57 (21) ◽  
pp. 3257-3264 ◽  
Author(s):  
Shuqi Guo ◽  
Naoto Hirosaki ◽  
Yoshinobu Yamamoto ◽  
Toshiyuki Nishimura ◽  
Hidehiko Tanaka
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Crack Growth ◽  
Slow Crack Growth ◽  
Silicon Nitride Ceramic

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

TEM Studies of Grain Boundary Films in Si3N4 Ceramics

1991 ◽  
Vol 49 ◽  
pp. 930-931
Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
Amorphous Film ◽  
Liquid Phase Sintering ◽  
Second Phase ◽  
High Temperature Mechanical Properties ◽  
Triple Points ◽  
Boundary Films

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.

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