AN ELECTRON MICROSCOPE STUDY OF THE SINTERING OF URANIUM OXIDE POWDER COMPACTS

Technical Report · Sun Jul 01 04:00:00 EDT 1962

OSTI ID:4803602

Ross, A M; Whitton, J L

Electron microscopy revealed the changes in microstructure that occurred in UO/sub 2/ powder compacts sintered in hydrogen for two hours at various temperatures between 790 and 1655 deg C. Sintering at temperatures up to 930 deg C caused no important changes in either the size or the shape of the powder particles. After sintering at 1070 deg C, most particles assumed more definitely polyhedral shapes, but still did not increase in size; the shape change was attributed to the growth of necks between particles. General particle growth (grain growth) occurred in the compacts sintered at the next highest temperature, 1155 deg C. The growth was markedly nonuniform, and, in compacts sintered at still higher temperatures, appeared to result in the retention of groups of small grains with numerous intergranular pores surrounded by a matrix of relatively large grains with a few intragranular pores. The islands of high porosity were thought to be the origin of relatively large pores located mainly at the intersections of grain boundaries in the compacts sintered at 1655 deg C. Possible causes for the uneven grain growth were considered. Of these the variation in particle size and presence of agglomerates in the original powder were believed important. (auth)

• Research Organization: Atomic Energy of Canada Ltd., Chalk River, Ont.
• NSA Number: NSA-16-027599
• OSTI ID: 4803602
• Report Number(s): CRFD-1100; AECL-1563
• Country of Publication: Canada
• Language: English

Related Subjects

CONFIGURATION
ELECTRON MICROSCOPY
GRAIN BOUNDARIES
GRAIN SIZE
HYDROGEN
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
PARTICLES
POROSITY
SINTERING
TEMPERATURE
URANIUM DIOXIDE