Sintering aids for yttria partially stabilized zirconia

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6891721

Montross, C S

High-purity yttria partially stabilized zirconia does not sinter readily. Commercial production of the powder and finished parts has allowed contamination by silica and aluminosilicates to enhance the sintering via a liquid-phase mechanism at 1400/sup 0/C. This research analyzed several simple metal oxides as possible nonglassy sintering aids to enhance the sintering of high-purity yttria partially stabilized zirconia, Y-PSZ, without the deleterious effects of the glass contamination. Of the metal oxides analyzed: iron oxide, bismuth oxide, chromia, niobia, tantala, tungsten oxide and mullite, only one metal oxide, iron oxide resulted in enhanced sintering. The iron oxide doped Y-PSZ exhibited better sinterability than high purity Y-PSZ and equivalent/better sinterability than glass doped Y-PSZ. The iron oxide doped Y-PSZ had a higher tetragonal content at lower sintering temperatures and at lower densities than glass doped Y-PSZ. This resulted in higher fracture toughness at lower temperatures than the glass doped Y-PSZ. Additionally, the iron oxide doped Y-PSZ showed a better resistance to low temperature high humidity degradation than glass doped Y-PSZ under identical conditions. Problems of bloating common to high surface area ultra fine powders and exhibited by the glass doped Y-PSZ were not alleviated by the use of the nonglassy metal oxide sintering aids.

• Research Organization: Washington Univ., Seattle (USA)
• OSTI ID: 6891721
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CHALCOGENIDES
FABRICATION
GLASS
IMPURITIES
METALLURGICAL EFFECTS
OXIDES
OXYGEN COMPOUNDS
SINTERING
STABILIZATION
TRANSITION ELEMENT COMPOUNDS
VERY HIGH TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES