Integrated study of the ceramic processing of yttria

Technical Report · Sun Jun 01 04:00:00 EDT 1986

OSTI ID:5163741

Voigt, J A

The preparation of a yttria ceramic, beginning with the continuous precipitation of a yttrium hydroxynitrate precursor by the reaction between yttrium nitrate and ammonium hydroxide, was studied to find the interrelationships among the various processing steps. Emphasis was placed on the effect of precipitation conditions on the characteristics of the precursor powder; the effect of these initial powder properties on the product from the subsequent calcination, pressing, and sintering operations was then examined. The precipitation process was modeled using a population balance approach which included the competitive kinetic rate effects of nucleation, crystal growth, agglomeration, and agglomerate break-up. The crystallites formed at low pH were platelet-shaped and formed weak, porous flocs. The nucleation and crystal growth kinetics for the precipitation of yttrium hydroxynitrate showed a marked discontinuity at a precipitation pH of approx.8.9.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5163741
• Report Number(s): IS-T-1158; ON: DE87000182
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CHALCOGENIDES
CRYSTAL GROWTH
NUCLEATION
OXIDES
OXYGEN COMPOUNDS
PH VALUE
POWDERS
PRECIPITATION
PROCESSING
REMOVAL
SEPARATION PROCESSES
TRANSITION ELEMENT COMPOUNDS
WATER REMOVAL
YTTRIUM COMPOUNDS
YTTRIUM OXIDES