Degration of partially stabilized zirconia ceramics under an applied stress

2003 ◽  
Vol 18 (1) ◽  
pp. 17-19 ◽  
Author(s):  
Shen Qiang ◽  
Zhang Lian-meng ◽  
Li Jun-guo ◽  
Wang Chuan-bin
Keyword(s):  
Applied Stress ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Partially Stabilized Zirconia

Electrical conductivity of yttria partially stabilized zirconia ceramics

1985 ◽  
Vol 4 (4) ◽  
pp. 467-471 ◽  
Author(s):  
M. Kuwabara ◽  
T. Murakami ◽  
M. Ashizuka ◽  
Y. Kubota ◽  
T. Tsukidate
Keyword(s):  
Electrical Conductivity ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Partially Stabilized Zirconia ◽  
Yttria Partially Stabilized Zirconia

scholarly journals Two-Step Sintering of Partially Stabilized Zirconia for Applications in Ceramic Crowns

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1857
Author(s):  
Bobby Aditya Darmawan ◽  
John G. Fisher ◽  
Doan Thanh Trung ◽  
Kumaresan Sakthiabirami ◽  
Sang-Won Park
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tooth Enamel ◽  
Milled Powder ◽  
Second Step ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Partially Stabilized Zirconia ◽  
Ceramic Crowns ◽  
Equal Density

Partially-stabilized zirconia is used in ceramic crowns due to its excellent mechanical properties and bio-inertness but does not match the natural color and translucency of tooth enamel. To reduce scattering of light and improve translucency, the grain size of zirconia ceramics should be less than the wavelength of visible light (0.4–0.7 μm), and porosity should be eliminated. The aim of the present work was to study the effect of two-step sintering of a commercial powder (Zpex Smile, Tosoh Corp., Tokyo, Japan) on the grain size and translucency of zirconia for use in ceramic crowns. Samples were sintered at a first step temperature (T1) of 1300, 1375 and 1400 °C for 5 min, followed by a decrease to the second step temperature (T2) and holding at T2 for 5–20 h. Samples were also conventionally sintered at 1450 °C for 2 h for comparison. Two-step sintered samples with an almost equal density, smaller grain size and narrower grain size distribution compared to conventionally sintered samples could be sintered. However, the translucency of two-step sintered samples had lower values compared to conventionally sintered samples. This is due to the slightly higher porosity in the two-step sintered samples. Density and translucency of both conventionally and two-step sintered samples could be increased further by using a ball milled powder.

Microcracks and Micro-Twins in Partially Stabilized Zirconia Alloys (PSZ)

1985 ◽  
Vol 43 ◽  
pp. 220-221
Author(s):  
Y.N. Lu ◽  
N.J. Tighe
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Intergranular Phase ◽  
Partially Stabilized Zirconia ◽  
Cubic Phases ◽  
Pure Zirconia ◽  
Before And After

Three commercial magnesia-doped partially stabilized zirconia ceramics (Nilsen MS and TS and Coors TT), have been examined before and after aging for 100 hours at 1000°C The proposed use of these ceramics for components in diesel engines requires long term reliability at temperatures up to 1000°C. The microscopy is being used to identify the microstructural changes that can result during high temperature tests carried out in this laboratory.Pure zirconia exists in three polymorphs which on cooling transform from cubic to tetragonal (at -2200°C) to monoclinic (at -950°C). With MgO additions and under appropriate conditions of temperature and time, the tetragonal to monoclinic transition can be controlled to produce partially stabilized magnesia zirconia alloys with grains and intergranular phases that are mixtures of monoclinic, tetragonal and cubic phases. The morphology of the grains and intergranular phases is readily distinguished in polished sections; however, the phase distributions can be confirmed only with electron microscopy. For example, the intergranular phase is predominantly monoclinic and grains can have: transgranular monoclinic plates in a cubic matrix; twinned monoclinic plates in a cubic matrix; distributions of tetragonal precipitates in a cubic matrix. The microcracks are found by examining interfacial regions at high magnifications.

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