Tetragonal zirconia polycrystal (TZP)—A review

Nettleship, Ian; Stevens, R.

doi:10.1016/0267-3762(87)90060-9

Cited by 177 publications

(73 citation statements)

References 24 publications

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“…8(e)), indicating that the endothermic peak is a sign of ZrB 2 formation. As already known, monoclinic ZrO 2 transforms into tetragonal structure at about 1170 °C (Nettleship and Stevens, 1987). However, there is no indication of this transformation in the DSC scan (Fig.…”

Section: Annealing Of the Milled Powdersmentioning

confidence: 62%

Microstructural Evaluation of ZrB2/ZrO2 Ceramic Powders Prepared by Milling-Assisted Magnesiothermic Reduction of Oxide Raw Materials

Ağaoğulları

Balcı

Öveçoğlu

et al. 2017

KONA

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This study reports on the synthesis and microstructural evaluation of ZrB 2 /ZrO 2 ceramic powders prepared by milling-assisted magnesiothermic reduction of oxide raw materials. Powder blends containing ZrO 2 , B 2 O 3 and Mg reactants were milled in different type of mills at different durations and were subsequently annealed in a tube furnace under Ar atmosphere. An additional purification step (HCl leaching) was conducted on the milled and annealed samples to obtain only Zr-based products. FactSage TM thermochemical software was used in order toshow a preliminary route for the experiments. The effects of milling duration (up to 100 h), milling type (a SPEX TM 8000D Mixer/Mill and a planetary ball mill), excess Mg amount (5-20 wt.%) and annealing duration (6 and 12 h) on the formation and microstructure of the products were examined. The milled, annealed and leached products were characterized using an X-ray diffractometer (XRD), stereomicroscope (SM), scanning electron microscope (SEM) and differential scanning calorimeter (DSC). Pure ZrB 2 /ZrO 2 ceramic powders having particles in size range of 200 nm-1 μm and containing two different crystal structures of ZrO 2 phase (monoclinic and tetragonal) were obtained after milling in the SPEX TM 8000D Mixer/Mill for 30 h, annealing at 1200 °C for 12 h and leaching with 5 M HCl.

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Section: Annealing Of the Milled Powdersmentioning

confidence: 62%

Microstructural Evaluation of ZrB2/ZrO2 Ceramic Powders Prepared by Milling-Assisted Magnesiothermic Reduction of Oxide Raw Materials

Ağaoğulları

Balcı

Öveçoğlu

et al. 2017

KONA

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“…See Paper I for the characterization of that phase in a pseudobinary oxide compound. The tetragonal phase is the most commonly used phase and can be stabilized at STP by alloying with different early transition metal oxides, the most common being Y2O3 [58,59]. The cubic fluoride phase is used as electrolyte in solid-oxide fuel cells due to its high ionic conductance [60,61].…”

Section: Zro2 Polymorphsmentioning

confidence: 99%

Thin Film and Plasma Characterization of PVD Oxides

Landälv¹

2017

Linköping Studies in Science and Technology. Dissertations

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The state-of-the-art tools for machining metals are primarily based on a metal-ceramic composite (WC-Co) coated with different combinations of carbide, nitride and oxide coatings. Combinations of these coating materials are optimized to withstand specific wear conditions. Oxide coatings are especially desired because of their possible high hot hardness, chemical inertness with respect to the workpiece, and their low friction.This thesis deals with process and coating characterization of new oxide coatings deposited by physical vapor deposition (PVD) techniques, focusing on the Cr-Zr-O and Al-Cr-Si-O systems.The thermal stability of α-Cr0.28Zr0.10O0.61 deposited by reactive radio frequency (RF)-magnetron sputtering at 500 °C was investigated after annealing up to 870 °C. The annealed samples showed transformation of α-(Cr,Zr)2O3 and amorphous ZrOx-rich areas into tetragonal ZrO2 and bcc Cr. The instability of the α-(Cr,Zr)2O3 is surprising and possibly related to the annealing being done under vacuum, facilitating the loss of oxygen. The stabilization of the room temperature metastable tetragonal ZrO2 phase, due to surface energy effects, may prove to be useful for metal cutting applications. The observed phase segregation of α-(Cr,Zr)2O3 and formation of tetragonal ZrO2 with corresponding increase in hardness for this pseudo-binary oxide system also opens up design routes for pseudo-binary oxides with tunable microstructural and mechanical properties.The inherent difficulties of depositing insulating oxide films with PVD, demanding a closed circuit, makes the investigation of process stability an important part of this research. In this context, we investigated the influence of adding small amount of Si in Al-Cr cathode on plasma characteristics, process parameters, and coating properties. Si was chosen here due to a previous study showing improved erosion behavior of Al-Cr-Si over pure Al-Cr cathode without Si incorporation in the coating.This work shows small improvements in cathode erosion and process stability (lower pressure and cathode voltage) when introducing 5 at % Si in the Al70Cr30-cathode. This also led to fewer droplets at low cathode current and intermediate O2 flow. A larger positive effect on cathode erosion was observed with respect to cleaning the cathode from oxide contamination by increasing cathode current with 50%. However, higher cathode current also resulted in increased amount of droplets in the coating which is undesirable. Through plasma analysis the presence of volatile SiO species could be confirmed but the loss of Si through volatile SiO species was negligible, since the coating composition matched the cathode composition. The positive effect of added Si on the process stability at the cathode surface should be weighed against Si incorporation in the coating. This incorporation may or may not be beneficial for the final application since literature states that Si promotes the metastable γ-phase over the thermodynamically stable α-phase of pure Al2O3, contrary to the effect o...

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“…The common notation used in tetragonal zirconia polycrystal (TZP), literature [45] involves placing the cation symbol of the stabilizing oxide before the TZP abbreviation. In some cases the molarity of the stabilizing oxide will be indicated by a number before the cation symbol e.g.…”

Section: Characterization Of Zirconia and Ceria-stabilized Zirconiamentioning

confidence: 99%

Formation characterization and rheological properties of zirconia and ceria-stabilized zirconia

Nikumbh¹,

Adhyapak²

2010

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Zirconia and ceria-stabilized zirconia (12Ce-TZP) were synthesized by the dicarboxylate coprecipitation technique such as fumarate, succinate, tartarate and adipate. The formation of these dicarboxylate precursors was studied by elemental analysis, thermal analysis and infrared spectroscopy. The precursors were further decomposed at 650 o C for 2 hours to form respective zirconia and ceria-stabilized zirconia. The composition of these oxides was checked by Atomic absorption spectrometer and Energy dispersive X-ray analysis. The structural and morphological characterization of these oxides was done by using X-ray diffraction analysis, surface area, scanning electron micrographs and particle size distribution analysis. These properties were found depending to great extent on the nature of the precursors. The zirconia and ceria-stabilized zirconia obtained from adipate precursor were found to be good for slipcasting. The slips (i.e., suspensions) of these oxides with different solid contents were prepared at different pH with distilled water and ethanol as dispersing agents, with and without deflocculant. The suspension rheological flow (i.e., variation of shear stress and viscosity with shear rate) was determined. The minimum viscosities were observed at pH = 10.16 for ZrO 2 -water and pH = 10.26 for 12Ce-TZP-water system. The slip, green and sedimentation bulk density were measured.

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Tetragonal zirconia polycrystal (TZP)—A review

Cited by 177 publications

References 24 publications

Microstructural Evaluation of ZrB<sub>2</sub>/ZrO<sub>2</sub> Ceramic Powders Prepared by Milling-Assisted Magnesiothermic Reduction of Oxide Raw Materials

Microstructural Evaluation of ZrB<sub>2</sub>/ZrO<sub>2</sub> Ceramic Powders Prepared by Milling-Assisted Magnesiothermic Reduction of Oxide Raw Materials

Thin Film and Plasma Characterization of PVD Oxides

Formation characterization and rheological properties of zirconia and ceria-stabilized zirconia

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