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Activated Sintering of ThO 2 and ThO 2 ‐Y 2 O 3 with NiO
Author(s) -
HALBFINGER GEORGE P.,
KOLODNEY MORRIS
Publication year - 1972
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1972.tb13420.x
Subject(s) - sintering , materials science , non blocking i/o , isothermal process , shrinkage , scanning electron microscope , analytical chemistry (journal) , diffusion , yield (engineering) , micrography , metallurgy , mineralogy , composite material , chemistry , thermodynamics , biochemistry , physics , chromatography , catalysis
The effect of additives on the sintering of ThO 2 and ThO 2 ‐Y 2 O 3 compacts and loose powders was studied by isothermal shrinkage measurements and by scanning electron micrography. Small amounts of the oxides of Ni, Zn, Co, and Cu reduced the sintering temperature. The behavior of NiO at a concentration of 0.8 wt% (2.5 mol%) was studied in detail and found to yield high‐density bodies at temperatures below 1500°C. The presence of Y 2 O 3 as a separate phase increases the rate of sintering of ThO 2 , but smaller amounts of NiO are much more potent. The major portion of the densification occurs very rapidly and is followed by a much slower sintering process typical of volume diffusion. The fast early shrinkage may be caused by the capillary forces of a liquid, but since no evidence of melting was found, a solid‐state mechanism may be responsible.