Effect of additives on sintering of zirconia ceramics

Ghyngazov, S. A.; Shevelev, S. A.

doi:10.1007/s10973-018-7249-0

Cited by 10 publications

(4 citation statements)

References 29 publications

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“…Another explanation concerning colour darkening was solubility and ion exchange. Better solubility as well as exchange of Zr 4+ and colouring metal ions are promoted by higher sintering temperatures [5,17,18]. However, a study concerning an ultrafine ZrO2-Y2O3-CeO2-Al2O3-CoO system [5] reported that the formation of CoAl2O4 and the reversible phase transformation of ZrO2 solid solution as a function of heat treatment attributed to colour alteration.…”

Section: Resultsmentioning

confidence: 99%

Debinding behaviour and sintering temperature-dependent features of coloured zirconia fabricated by ceramic injection moulding

2021

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Zirconia (ZrO2) is one of ceramic materials that has very good mechanical and chemical properties suitable for biomedical applications as well as other industrial applications. ZrO2 ceramics, in fact, has been used in orthodontic dentistry. Nowadays, ZrO2 has been played its role in decorative and jewelry purposes, such as watchcases and artificial stones. Ceramic injection moulding (CIM), a near-net shape manufacturing process that can produce small, complex-shaped components and is suitable for large volume production, is one of the best powder fabrication methods. In this work, CIM was carried out in order to form the coloured-ZrO2 specimens. Binders used in the feedstock preparation are composed mainly of polyethylene glycol (PEG) and polyvinyl butyral (PVB). A laboratory-scaled, plunger-typed injection moulding machine was used to fabricate the coloured-ZrO2 components with various sizes and shapes. Debinding was carried out by water immersion and thermal debinding. Various sintering conditions were also performed. The specimens after sintering were subjected to be characterised and tested. The results showed that the binder removal rates using water related to geometry of the specimens, surface area and volume were taken into account. Sintering temperatures played important roles on properties, microstructure as well as the appearance and shades of the coloured-ZrO2 fabricated by ceramic injection moulding.

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Section: Resultsmentioning

confidence: 99%

Debinding behaviour and sintering temperature-dependent features of coloured zirconia fabricated by ceramic injection moulding

2021

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“…The residual gases in the pores increase the pore volume due to thermal expansion, which increases the volume of the ceramics sintered. The validity of this assertion is confirmed by data in [24], which investigates the effect of low-melting bismuth oxide additives on sintering of zirconia ceramics. In compacts made from powders P2 and P3, the expansion of ceramics at the isothermal stage is not observed, since the compacts contained a smaller amount of gas adsorbates (Fig.…”

Section: Resultsmentioning

confidence: 68%

Investigation with using thermal analysis of gas evolution and sintering of nanopowders of zirconia prepared by sol-gel method

Sheveleva¹,

Shevelev²,

Sokolovskiy³

et al. 2020

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Thermal and XRD analyses were used to study partially stabilized zirconia powders produced by sol-gel method in order to investigate gas evolution in annealing in air and densification behavior of these powders in compaction and subsequent sintering. It was found that the powders of the initial gel contain a large amount of gas adsorbates. The amount of adsorbates decreases as the annealing temperature grows. At annealing temperature of 700 ºC, adsorbates are completely removed from the powders and the latter obtain a crystalline structure with a predominant tetragonal phase. Gas adsorbates affect densification of powder compacts during sintering and facilitate the production of ceramics with a porosity of not more than 5 %. It is shown that the production of low porosity ceramics is complicated even though powders subjected to annealing may contain nano-sized impurities or be free of these. Low-melting additives are proposed to be used for ceramics production.

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“…A known approach to modification of oxide ceramic properties is the use of different oxide additives [8][9][10]. Their incorporation into the initial lattice may affect the rates of sintering and grain growth or lead to liquid phase formation.…”

Section: Introductionmentioning

confidence: 99%

Bi2O3-Modified Ceramics Based on BaTiO3 Powder Synthesized in Water Vapor

et al. 2020

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Bi2O3 was investigated in the role of a modifier for BaTiO3 powder synthesized in a water vapor atmosphere at 200 °C and 1.55 MPa. Modification was aimed at increasing the sinterability of the powder as well as improving the structural and dielectric properties of the obtained ceramics. The morphology and phase contents of the synthesized BaTiO3 powder were controlled by the methods of SEM and XRD. Properties of pure and Bi-doped BaTiO3 ceramics were comprehensively studied by XRD, SEM, dielectric spectroscopy, and standard approaches for density and mechanical strength determination. Doping with Bi2O3 favored BaTiO3 ceramic densification and strengthening. The room-temperature dielectric constant and the loss tangent of Bi-doped BaTiO3 were shown to stabilize within the frequency range of 20 Hz to 2 MHz compared to non-doped material. The drop of dielectric constant between room temperature and Curie point was significantly reduced after Bi2O3 addition to BaTiO3. Bi2O3 appeared to be an effective modifier for BaTiO3 ceramics produced from non-stoichiometric powder synthesized in water vapor.

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Effect of additives on sintering of zirconia ceramics

Cited by 10 publications

References 29 publications

Debinding behaviour and sintering temperature-dependent features of coloured zirconia fabricated by ceramic injection moulding

Debinding behaviour and sintering temperature-dependent features of coloured zirconia fabricated by ceramic injection moulding

Investigation with using thermal analysis of gas evolution and sintering of nanopowders of zirconia prepared by sol-gel method

Bi2O3-Modified Ceramics Based on BaTiO3 Powder Synthesized in Water Vapor

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