551 Micromechanical Analysis of Stress-Induced Transformation-Toughening in Partially Stabilized Zirconia

2001 ◽  
Vol 2001 (0) ◽  
pp. 583-584
Author(s):  
Shigetoshi ARAKI ◽  
Kenji SAITO ◽  
Hiroyuki ONO
Keyword(s):  
Transformation Toughening ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Micromechanical Analysis

Examination of CaO-Dy2O3 for potential use as a high-temperature transformation toughening System

1988 ◽  
Vol 46 ◽  
pp. 790-791
Author(s):  
M. M. Fleming ◽  
W. M. Kriven
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Transformation Toughening ◽  
Stabilized Zirconia ◽  
Two Phase ◽  
Volume Increase ◽  
Partially Stabilized Zirconia ◽  
Temperature Transformation ◽  
Fast Quenching ◽  
Potential Use

Similarities exist between the tetragonal to monoclinic transformation of ZrO2 and the monoclinic (B) to cubic (C) transformation of Dy2O3. On cooling the transformation occurs at 1950°C and is accompanied by an 8 % volume increase which causes shattering of bulk specimens. The transformation can be suppressed, however, by minor additions of CaO. An attempt was made to fabricate a “PSD” analogue to partially stabilized zirconia (PSZ).As-received and chemically precipitated powders of pure Dy2O3 were mixed with CaO (0 to 25 mol%), uniaxially and cold isostatically pressed, sealed in small Mo crucibles and sintered at various temperatures (1900° or 1650°C) and times before cooling or subsequent annealing treatments. Some pellets were annealed in the two phase (B + C) region at 1700°C for 2 hours before quenching. Specimens were examined by XRD, TEM, EDS, HVEM, and STEM.A fast quenching in combination with the =8 mol% CaO additions were found to be essential for retention of the high temperature B phase down to room temperature.

Displacive Phase Transformations in Zirconia-Based Ceramics

1986 ◽  
Vol 78 ◽  
Author(s):  
B. C. Muddle
Keyword(s):  
Habit Plane ◽  
Orientation Relationship ◽  
Tetragonal Zirconia ◽  
Formal Theory ◽  
Orthorhombic Phase ◽  
Thin Foil ◽  
Intermediate Stage ◽  
Transformation Toughening ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia

ABSTRACTA review is presented of experimental observations of the mechanism and crystallography of the martensitic tetragonal to monoclinic transformation occurring both in dispersed tetragonal ZrO2 particles in partially stabilized zirconia and in polycrystalline tetragonal zirconia. Preliinary results of determination of the orientation relationship and habit plane for the stress-activated transformation in a CeO2 –stabilized TZP ceramic are reported and compared with predictions of the crystallographic theory for the transformation. This orientation relationship is such that (100)m//(100)t and [001]m//[001]m, and for this variant of the orientation relationship the habit plane is approximately ( 301 )t. These results are in good agreement with theoretical predictions. Progress in the application of the formal theory of martensitic transformations to the transformations in both types of system is examined critically and implications for theories of transformation toughening are discussed.Attention is also given to tetragonal orthorhombic and orthorhombic monoclinic transformations occurring in Zro2 particles in thin foil specimens of partially stabilized zirconia. Formation of a metastable orthorhombic phase appears a possible, but not essential, intermediate stage in the tetragonal to monoclinic transition. However, present evidence strongly suggests that the orthorhombic structure only occurs in those particles experiencing the relaxed matrix constraints typical of thin foil specimens.

Transformation-toughening in partially-stabilized zirconia (PSZ)

1979 ◽  
Vol 27 (10) ◽  
pp. 1649-1654 ◽  
Author(s):  
D.L. Porter ◽  
A.G. Evans ◽  
A.H. Heuer
Keyword(s):  
Transformation Toughening ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia

A mode of deformation in partially stabilized zirconia

1981 ◽  
Vol 16 (5) ◽  
pp. 1428-1431 ◽  
Author(s):  
R. H. J. Hannink ◽  
M. V. Swain
Keyword(s):  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia

A ceramic based on partially stabilized zirconia: Synthesis, structure, and properties under dynamic load

2011 ◽  
Vol 49 (5) ◽  
pp. 685-689 ◽  
Author(s):  
V. V. Milyavskii ◽  
A. S. Savinykh ◽  
F. A. Akopov ◽  
L. B. Borovkova ◽  
T. I. Borodina ◽  
...  
Keyword(s):  
Dynamic Load ◽  
Structure And Properties ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia
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