Indentation Induced Deformation and Crack Behavior of β-SiC Irradiated at High Temperature

Author(s):  
Kyeon Hwan Park ◽  
Tatsuya Hinoki ◽  
Akira Kohyama
1999 ◽  
Vol 25 (5) ◽  
pp. 179-187
Author(s):  
Satoshi KOBAYASHI ◽  
Nobuo TAKEDA ◽  
Mikio OBA ◽  
Shinji OGIHARA ◽  
Akira KOBAYASHI

2015 ◽  
Vol 750 ◽  
pp. 376-381
Author(s):  
Wen Fu Liang ◽  
Tong Liu ◽  
Min Shan Liu

Three-dimensional crack behavior simulation analysis and anti-fracture design have been a main subject in fracture theory and engineering application. Piping system is a key part of nuclear power engineering. Utilizing the three-dimensional finite element analysis software ANSYS and the specialized crack analysis programs Franc3D, three-dimensional crack behavior and leak before break (LBB) case were simulated and evaluated of a pipe with a crack in waste heat exhaust system of China Experimental Fast Reactor ( CEFR ). In fast reactor, the piping is working under a high temperature. Therefore, the code RCC-MR.A16 was adopted that is suitable for materials and structural safety design at high temperature. Material used in this article is modified 9Cr1Mo-T91/P91. The analysis model of pipe section was built in three-dimensional entity structure containing a cracks and the high temperature and creep effects were considered. The simulation results show that creep contributes more effect on crack growth than fatigue. The evaluation results on LBB of studied T91 steel pipe with a crack-like defect can satisfy the need of LBB design guidelines. The research results can be referenced in pipe material choose, safety assessment and structural integrity evaluation of a pipe containing defects at high temperature in a fast reactor design.


2016 ◽  
Vol 713 ◽  
pp. 273-276
Author(s):  
Cheol Jun Park ◽  
Ji Woong Kang ◽  
Oh Heon Kwon

The crack formation and propagation remain as major issues regarding the mechanical crack behavior of solid oxide fuel cell (SOFC), due to the thermomechanical mismatch and the porous nature of the SOFC components. The SOFC consisting of brittle ceramic materials can be damaged by the cracking due to high-temperature during the manufacturing and operation. The crack generated during the manufacturing were can cause the cell performance degradation during operation. For crack evaluation because the SOFC products the required power density through the stack considering the interconnector is required. The purpose of this study is to investigate the effect of the vertical crack at the cathode electrode, and also the effects of the crack on the interconnect channel position in operation for the crack behavior and stress field.


Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.


Author(s):  
B. J. Hockey

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.


Author(s):  
D. R. Clarke ◽  
G. Thomas

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.


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