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Densification of Calcia‐Stabilized Zirconia with Borates
Author(s) -
Buchanan Relva C.,
Sircar Anup
Publication year - 1983
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.1151-2916.1983.tb09998.x
Subject(s) - monoclinic crystal system , sintering , cubic zirconia , materials science , boron , leaching (pedology) , phase (matter) , mineralogy , grain growth , grain size , metallurgy , analytical chemistry (journal) , chemical engineering , crystallography , chemistry , crystal structure , ceramic , chromatography , organic chemistry , geology , soil science , engineering , soil water
Densification studies of submicrometer ZrO 2 powders stabilized with 6.5 wt% CaO (CSZ) showed borate additions (1 to 10 wt%) to be effective sintering aids. Estimated densities >99% of theoretical were obtained on sintering at 1200°Cfor 4 h with 2 wt% B 2 O 3 or 5 wt% CaO·2B 2 O 3 additions to the CSZ powders. Average grain sizes obtained were typically <1 μm. Partial development of a monoclinic ZrO 2 phase was observed in the sintered samples. The amount of this phase varied from ∼7 to 75 wt% and was approximately linearly dependent on the additive concentration. The effect was most marked for the B 2 O 3 additions. Development of the monoclinic phase was attributed to progressive leaching of Ca from the CSZ phase by B 2 O 3 , in effect partially destabilizing the ZrO 2 .