Pro- and Subeutectoid Behavior of the Tetragonal Phase in Magnesia-Partially-Stabilized Zirconia

1992 ◽  
Vol 75 (2) ◽  
pp. 463-468 ◽  
Author(s):  
Charles S. Montross
Author(s):  
Riccardo Marin ◽  
Gabriele Sponchia ◽  
Michele Back ◽  
Pietro Riello

A method is reported for assessing the compositional fluctuations in a ceramic sample, based only on the determination of the crystalline lattice parameters. Pure tetragonal phase partially stabilized zirconia powders are synthesized through the co-precipitation method by incorporating 4% Eu3+. The powder is subjected to compression cycles to promote the tetragonal-to-monoclinic transformation. The Rietveld analysis of the X-ray powder diffraction patterns, recorded after each compression cycle, gives information about the lattice parameters and monoclinic phase content. The determination of europium content in the residual tetragonal phase is accomplished considering the unit cell volume oft-ZrO2using Vegard's law. Using this information the compositional fluctuations over the sample were determined by considering two possible distributions of lanthanide ion content in the powders: a Gaussian and a Log-normal one. It was found that the Gaussian distribution better fits the experimental data. It was eventually demonstrated that these results are physically meaningful.


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

2011 ◽  
Vol 49 (5) ◽  
pp. 685-689 ◽  
Author(s):  
V. V. Milyavskii ◽  
A. S. Savinykh ◽  
F. A. Akopov ◽  
L. B. Borovkova ◽  
T. I. Borodina ◽  
...  

2009 ◽  
Vol 24 (6) ◽  
pp. 2021-2028 ◽  
Author(s):  
R. Milani ◽  
R.P. Cardoso ◽  
T. Belmonte ◽  
C.A. Figueroa ◽  
C.A. Perottoni ◽  
...  

High temperature plasma nitriding of yttria-partially-stabilized zirconia in atmospheric pressure microwave plasma was investigated. The morphological, mechanical, and physicochemical characteristics of the resulting nitrided layer were characterized by different methods, such as optical and scanning electron microscopy, microindentation, x-ray diffraction, narrow resonant nuclear reaction profiling, secondary neutral mass spectrometry, and x-ray photoelectron spectroscopy, aiming at investigating the applicability of this highly efficient process for nitriding of ceramics. The structure of the plasma nitrided layer was found to be complex, composed of tetragonal and cubic zirconia, as well as zirconium nitride and oxynitride. The growth rate of the nitrided layer, 4 µm/min, is much higher than that obtained by any other previous nitriding process, whereas a typical 50% increase in Vickers hardness over that of yttria-partially-stabilized zirconia was observed.


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