Structural effect in neutron irradiation of insulating ceramics
A vacuum gap irradiation capsule was designed and built to maintain a temperature of 740/sup 0/C during 6 weeks irradiation at EBR-II. Sixty-eight samples of 15 ceramic or metal-ceramic combinations were irradiated to a fluence of approximately 3 x 10/sup 21/ neutrons/cm/sup 2/, E greater than 0.1 MeV. Measurements of sample dimensions before and after irradiation were used to determine volume swelling. This parameter and the physical appearance of the samples are discussed. A primary application of insulating ceramics in proposed fusion powder devices is the first wall insulating lining in the RTPR reactor. A satisfactory material for this application must bear substantial thermal stresses in cyclical fashion. Calculated values of pertinent parameters are presented and compared for several of the irradiated materials in non-irradiated form. Work to prepare apparatus for the measurement of thermal and mechanical properties of these materials following neutron irradiation is described. Silicon nitride is representative of a class of refractory ceramics distinguished by its high thermal conductivity, resistance to thermal shock, and elevated temperature strength retention. Recent work has suggested that Si/sub 3/N/sub 4/ hot pressed with additions of Y/sub 2/O/sub 3/, rather than the usual MgO, may offer improved high temperature strength. A project to prepare samples of this material with optimized Y/sub 2/O/sub 3/ concentration and pressing conditions is described. Samples of Si/sub 3/N/sub 4/ hot pressed with 0, 5, 10, 15, and 20 wt percent Y/sub 2/O/sub 3/ additions have been prepared for an irradiation experiment being carried out by ORNL at EBR-II.
- Research Organization:
- Los Alamos Scientific Lab., N.Mex. (USA)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 7269287
- Report Number(s):
- LA-UR-76-1131; CONF-760558-1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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Cermets
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ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARYONS
BEAMS
BERYLLIUM COMPOUNDS
BERYLLIUM OXIDES
BREEDER REACTORS
CERAMICS
CERMETS
CHALCOGENIDES
COMPOSITE MATERIALS
DIELECTRIC MATERIALS
EBR-2 REACTOR
ELEMENTARY PARTICLES
EPITHERMAL REACTORS
EXPERIMENTAL REACTORS
FABRICATION
FAST NEUTRONS
FAST REACTORS
FBR TYPE REACTORS
FERMIONS
GLASS
HADRONS
HOT PRESSING
LIQUID METAL COOLED REACTORS
MATERIALS WORKING
NEUTRON BEAMS
NEUTRONS
NITRIDES
NITROGEN COMPOUNDS
NUCLEON BEAMS
NUCLEONS
OXIDES
OXYGEN COMPOUNDS
PARTICLE BEAMS
PHYSICAL RADIATION EFFECTS
PNICTIDES
POWER REACTORS
PRESSING
RADIATION EFFECTS
REACTORS
RESEARCH AND TEST REACTORS
SILICON COMPOUNDS
SILICON NITRIDES
SODIUM COOLED REACTORS
THERMONUCLEAR REACTOR MATERIALS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES