Radiation effects and micromechanics of SiC/SiC composites. Annual technical report, November 15, 1991--November 14, 1992
The basic displacement damage process in SiC has been fully explored, and the mechanisms identified. Major modifications have been made to the theory of damage dosimetry in Fusion, Fission and Ion Simulation studies of Sic. For the first time, calculations of displacements per atoms in SiC can be made in any irradiation environment. Applications to irradiations in fusion first wall neutron spectra (ARIES and PROMETHEUS) as well as in fission spectra (HIFIR and FFTF) are given. Nucleation of helium-filled cavities in SiC was studied, using concepts of stability theory to determine the size of the critical nucleus under continuous generation of helium and displacement damage. It is predicted that a bimodal distribution of cavity sizes is likely to occur in heavily irradiated SiC. A study of the chemical compatibility of SiC composite structures with fusion reactor coolants at high-temperatures was undertaken. It was shown that SiC itself is chemically very stable in helium coolants in the temperature range 500--1000{degree}C. However, current fiber/matrix interfaces, such as C and BN are not. The fracture mechanics of high-temperature matrix cracks with bridging fibers is now in progress. A fundamentally unique approach to study the propagation and interaction of cracks in a composite was initiated. The main focus of our research during the following period will be : (1) Theory and experiments for the micro-mechanics of high-temperature failure; and (2) Analysis of radiation damage and microstructure evolution.
- Research Organization:
- California Univ., Los Angeles, CA (United States). Dept. of Mechanical, Aerospace and Nuclear Engineering
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG03-91ER54115
- OSTI ID:
- 10187998
- Report Number(s):
- DOE/ER/54115-T2; ON: DE93003268
- Resource Relation:
- Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
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Radiation effects and micromechanics of SiC/SiC composites (December 1, 1990--November 14, 1993) and modeling the mechanical behavior of SiC/SiC composites in fusion environments (November 15, 1993--November 14, 1996). Final report, December 1, 1990--November 14, 1996
Phenomenological inelastic constitutive equations for SiC and SiC fibers under irradiation
Related Subjects
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
SILICON CARBIDES
RADIATION EFFECTS
FRACTURE PROPERTIES
PROGRESS REPORT
POINT DEFECTS
ATOMIC DISPLACEMENTS
MICROSTRUCTURE
CAVITIES
NUCLEATION
COMPATIBILITY
THERMONUCLEAR REACTORS
COMPOSITE MATERIALS
FIBERS
REINFORCED MATERIALS
CRACK PROPAGATION
360206
360603
700480
MECHANICAL PROPERTIES
COMPONENT DEVELOPMENT
MATERIALS STUDIES