A framework for modeling complicated global energy landscapes in a piecewise manner is presented. Specifically, a class of strain-dependent energy functions is derived for the triple point of Zirconia (ZrO2), where tetragonal, orthorhombic (orthoI) and monoclinic phases are stable. After presenting a simple two-dimensional framework to deal with this symmetry breaking, an explicit energy is fit...

objective: despite the high strength of zirconia restorations, aging in the oral environment and masticatory loading may result in transformation of tetragonal to monoclinic phase and decrease their strength. statements in this regard are controversial. this study sought to compare the flexural strength (fs) of zirkonzahn (zirkonzahn, cercon, ceramill) and mamut (dubai medical equipment llc, du...

Alumina-zirconia (AZ) composites are attractive structural materials, which combine the high hardness and Young's modulus of the alumina matrix with additional toughening effects, due to the zirconia dispersion. In this study, AZ composites containing different amounts of zirconia (in the range 5-20 vol %) were prepared by a wet chemical method, consisting on the surface coating of alumina powd...

In this study various yttria doped  zirconia based thin films were prepared by the aqueous tape casting method. The rheological property of the paste was studies. The phase content and microstructure of the samples was investigated by X-ray diffraction and scanning electron microscope, respectively. The mechanical properties of thin films were studied by Vickers microhardness and nanoindentatio...

Tetragonal zirconia (t-ZrO2) nanoparticles were synthesized from thezirconium chloride using the co-precipitation technique and characterized by variousmeasurement techniques. FESEM analysis further revealed spherical shaped NPs andHR-TEM analysis determined the size of the particles in the range of 14.5 nm. The bandgap energy was estimated 4.0 eV. The UV (350 nm) emissi...

SOME CONWJWENCX~ of a simple theoretical model for the stress-induced, isothermal phase transformation of an isolated tetragnnal zirconia crystal are studied. The transformation to a monoclinic state is viewed as mechanical buckling from one homogeneous geometrical configuration to another. The model is used to predict the manner in which an applied shear stress should interact with hydrostatic...

Objective: To evaluate the effect of different metal primers and surface treatment methods on the bond strength of 2 resin cements to yttrium-stabilized tetragonal zirconia (Y-TZP) ceramic material. Methods: 240 cylindrical dentin specimens were cut from extracted human third molars. The same number of zirconia ceramic (Cercon) plates were made and assigned to 24 groups based on combinations of...

Zirconium oxide (ZrO2) has generated wide interest because of its potential in applications such as solid oxide fuel cells, catalysts and optical devices. In these applications, it is important to control the grain size of the material and increase the surface area by introducing porosity with tailored pore size. This paper presents a synthesis route for the preparation of mesoporous zirconia u...

The objective of the study was to evaluate the effect of veneering zirconia surfaces with feldspar-based ceramics or glass ceramics on bond strength when using a resin composite cement. Forty-eight ytteria tetragonal zirconia polycrystal (Y-TZP) specimens were randomly divided into four groups. Six pairs were created in each group by bonding two of the specimens to each other after having the b...