High remnant polarization of (K0.5Na0.5)0.99(Ba0.0025Sr0.0025)NbO3 piezoceramics with nano-CuO sintering aid

2021 ◽  
Vol 127 (8) ◽  
Author(s):  
Hajar Ahmadimoghadam ◽  
Mehdi Delshad Chermahini
Author(s):  
W. W. Davison ◽  
R. C. Buchanan

Yttria stabilized zirconia (YSZ) has become a significant technological material due to its high ionic conductivity, chemical inertness, and good mechanical properties. Temperatures on the order of 1700°C are required, however, to densify YSZ to the degree necessary for good electrical and mechanical properties. A technique for lowering the densification temperature is the addition of small amounts of material which facilitate the formation of a liquid phase at comparatively low temperatures. In this study, sintered microstructures obtained from the use of Al2O3 as a sintering aid were examined with scanning, transmission, and scanning transmission microscopy (SEM, TEM, and STEM).


2008 ◽  
Vol 591-593 ◽  
pp. 436-440
Author(s):  
João Marcos K. Assis ◽  
Francisco Piorino Neto ◽  
Francisco Cristóvão Lourenço de Melo ◽  
Maria do Carmo de Andrade Nono

A comparative study between alumina added niobia ceramics and two alumina zirconia composites from nanostructured TZP (7% and 14% weight) was made. On this composites the zirconia were yttria stabilized and the alumina were submicron structured. As sintering aid a mixture of magnesia, niobia and talc were used on all samples. The sintering was performed at 1450 oC during 60 minutes. The characteristic grain size and shape of an alumina and zirconia powders, aggregates and agglomerates were characterized. The sintering ceramics were evaluated through hardness, fracture toughness and 4 point bending test. Weibull statistic was applied on the flexural results. Although the fracture toughness result from ZTA were lower, and seems to be affected by the liquid fase, the hardness and Weibull modulus were higher than alumina niobia. The grains size and the homogeneity of its distributions on the microstructure of this ceramics was correlated to these higher values. The results from these alumina zirconia composites showed a potential to apply as a ballistic armor material.


Author(s):  
Yuanye Huang ◽  
Rotraut Merkle ◽  
Joachim Maier

The effects of 0.125-0.2 wt% NiO added as sintering aid for highly refractory Ba(Zr,Ce,Y)O3-δ proton conducting ceramics are investigated. The complex nature of the solid state reactive sintering method shows...


1999 ◽  
Vol 25 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Amitava Chakraborty ◽  
Himadri S. Maiti
Keyword(s):  

1992 ◽  
Vol 287 ◽  
Author(s):  
Y. Sato ◽  
C. Sakurai ◽  
M. Ueki ◽  
K. Sugita

ABSTRACTA homogeneous mixture of Y2O3, CeO2 and MgO with a final weight ratio of 3:1: 2 was prepared by the alkoxide method. The powder mixture was then added into Si3N4 powder in amounts ranging from 4 to 12 wt%, andconsolidated by hot-pressing. Microstructure and mechanical properties of the sintered bodies were determined and compared to those of materials prepared by the conventional route of mixing the oxide powders as sintering aids individually in essentially same composition. The β-fraction (modification ratio) in same composition was higher in thesintered bodies made through the alkoxide method than those made through the conventional one. The room temperature flexural strength was maximized with 6wt% addition of the alkoxide derived oxide, whereas, 12wt% addition of the total oxide was required to maximize the strength by conventional processing.


Materialia ◽  
2019 ◽  
Vol 5 ◽  
pp. 100182
Author(s):  
S.F. Li ◽  
Y.F. Yang ◽  
K. Kondoh ◽  
S. Kariya ◽  
Q.S. Zhu ◽  
...  

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