Experiments in high voltage electron microscopy. Progress report, October 31, 1978-August 1979

Technical Report · Sat Jul 01 00:00:00 EDT 1978

DOI:https://doi.org/10.2172/5880184· OSTI ID:5880184

High voltage electron microscopy (HVEM) has been used to study radiation damage in metals and ceramics, along with supplemental investigations using neutron and ion irradiation. Studies of alloys have concentrated on radiation effects on phase stability, particularly precipitate growth and, most recently, order/disorder transitions. ..beta..-phase alloys (e.g., FeAl) disorder under irradiation, but also develop unique striated structures with streaks in the diffraction patterns (especially NiAl), which may be due to secondary defects or a second phase. In simple oxides such as MgO, Arrhenius plots of dislocation loop growth rates give a high temperature activation energy corresponding to vacancy migration and an apparent low temperature activation energy corresponding to interstitial migration. Both electron and neutron irradiation produce voids in Al/sub 2/O/sub 3/; in addition neutron-irradiated polycrystalline Al/sub 2/O/sub 3/ exhibits microcracking along grain-boundaries due to aisotropic swelling. Further studies of the radiation-induced metamictization of quartz have revealed that the strain centers which are observed prior to the general amorphization are probably amorphous inclusions; these inclusons are much more prominent in wet synthetic quartz than dry lunar quartz. Ceramics with more complex crystal structures are much more resistant to the formation of interstitial loops and voids (and hence swelling) under both electron and neutron irradiations.

• Research Organization: Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Metallurgy and Materials Science
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-S-02-2119
• OSTI ID: 5880184
• Report Number(s): COO-2119-22; TRN: 79-021480
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
PHYSICAL RADIATION EFFECTS
ALUMINIUM OXIDES
IRON ALLOYS
MAGNESIUM OXIDES
NICKEL ALLOYS
QUARTZ
YTTRIUM OXIDES
ELECTRON MICROSCOPY
ORDER-DISORDER TRANSFORMATIONS
PHASE STUDIES
SWELLING
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
MAGNESIUM COMPOUNDS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
RADIATION EFFECTS
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360106* - Metals & Alloys- Radiation Effects
360206 - Ceramics
Cermets
& Refractories- Radiation Effects