Dilatometric Study of U1−xAmxO2±δ Sintering: Determination of Activation Energy. Issue 11 (18th October 2013)

• Record Type: Journal Article
• Authors: Horlait, Denis; Lebreton, Florent; Delahaye, Thibaud; Blanchart, Philippe
• Editors: Bordia, R.
• Is Part Of: Journal of the American Ceramic Society. Volume 96:Issue 11(2013)
• Page Start: 3410
• Page End: 3416
• Publication Date: 2013-10-18
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12642
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract : In the framework of minor actinide bearing blanket fuel fabrication, the sintering of uranium/americium (U0.85 Am0.15 O2 ± δ ) homogeneous mixed‐oxide pellets was studied. After the characterization of the U0.85 Am0.15 O2 ± δ starting powder (granulometry, X‐ray diffraction, and scanning electron microscopy), its densification under a reducing atmosphere was monitored through dilatometric measurements and compared to a similar experiment with UO2+δ . During the heating phase, up to 2173 K, the U0.85 Am0.15 O2 ± δ pellet shrinks from 70 to 95%TD (theoretical density). Neck formation and growth initiate the densification of this pellet at 1200 K. Two subsequent mechanisms were also evidenced, and a maximum shrinkage rate was observed between 2000 and 2100 K, suggesting an optimal sintering temperature within this range. The associated activation energy ( Q ) of sintering process was also determined using three different models which yield values noticeably higher than those reported or measured for UO2 .