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Norziha Yahaya - One of the best experts on this subject based on the ideXlab platform.
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enhancement of the microstructural and mechanical properties of dental zirconia through combined optimized colloidal processing and Cold Isostatic Pressing
Ceramics International, 2019Co-Authors: Mohamed Aboras, Andanastuti Muchtar, Che Husna Azhari, Norziha YahayaAbstract:Abstract Agglomerates in 3 mol% yttria-stabilized tetragonal zirconia polycrystalline (3Y-TZP) powders introduce detrimental heterogeneities that drastically degrade the mechanical properties of the sintered zirconia. This study aimed to investigate the effectiveness of optimized colloidal processing combined with Cold Isostatic Pressing (CIP) in the production of high-density 3Y-TZP with enhanced microstructural and mechanical properties. First, 3Y-TZP suspensions were prepared through colloidal processing with polyethyleneimine (PEI) as a dispersant. After the addition of PEI, the pH of the suspension was adjusted to optimize colloidal stability, which was ascertained through zeta potential measurements. 3Y-TZP green bodies were consolidated through slip casting and allocated into two groups. One group was subjected to CIP, and the other was not. The density, phase structure, microstructure, hardness, and flexural strength of the as-sintered 3Y-TZP samples were then examined. The sample with the highest colloidal stability was obtained with the suspension pH of 2 and PEI addition of 0.4 wt%. The as-sintered 3Y-TZP structures produced without CIP provided a relative density of 93% with an undesired monoclinic phase content of 2.1%. By contrast, 3Y-TZP structures subjected to CIP exhibited a tetragonal phase content of 100% and better mechanical properties, higher density, and more homogeneous microstructures than structures that were not subjected to CIP. Given these results, the optimized colloidal process combined with CIP can be used to successfully produce highly dense and homogenous 3Y-TZP structures with enhanced mechanical properties.
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preparation of presintered zirconia blocks for dental restorations through colloidal dispersion and Cold Isostatic Pressing
Ceramics International, 2018Co-Authors: Noor Faeizah Amat, Andanastuti Muchtar, Mariyam Jameelah Ghazali, Muhammad Sufiyan Amril, Norziha YahayaAbstract:Abstract This work proposes an effective method for dispersion of zirconia suspension for dental block preparation and optimizes the Cold Isostatic Pressing (CIP) pressure to improve the densification of slip-casted zirconia blocks. Two batches of 44 wt% zirconia suspension were prepared using distilled water in a pH 2 medium containing 0.5 wt% polyethyleneimine as dispersant. The first batch was sonicated for different durations (from 5 min to 30 min), and the second batch was dispersed through ball milling at rotational speeds of 200, 300, and 400 rpm for 60, 90, and 120 min. All suspensions were subjected to sedimentation test and particle size measurement. Results revealed that the optimum ultrasonication duration was 10 min, which yielded the smallest particle size of 133 nm. Ball milling at 300 rpm for 120 min achieved the maximum dispersion of particles, with an average size of 75 nm. Under the optimum conditions of ultrasonication duration, ball milling duration, and ball milling speed, the particle size decreased to 48 nm, which is close to the primary particle size. These dispersion techniques and parameters were selected for preparing a suspension to be consolidated into blocks through slip casting and were enhanced through CIP at pressure ranging from 100 MPa to 300 MPa. CIP compaction at 250 MPa significantly increased the shrinkage percentage of green zirconia blocks, with pore radius decreased to 18 nm. The density of zirconia pressed at 250 MPa and presintered at a low temperature of 950 °C was 59% of the theoretical density and was higher than that of commercial presintered blocks. Thus, CIP should be conducted under a compaction pressure of 250 MPa to produce dense and homogeneous zirconia blocks.
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IMPROVEMENT OF MECHANICAL PROPERTIES OF Y-TZP VIA CERIA ADDITION AND Cold Isostatic Pressing METHOD
Jurnal Teknologi, 2015Co-Authors: Mohamed Aboras, Andanastuti Muchtar, Che Husna Azhari, Norziha YahayaAbstract:Fabrication and composition of tetragonal zirconia have been extensively studied to enhance its mechanical properties. The present study aims to investigate the mechanical properties of yttrium-stabilized zirconia (Y-TZP) with ceria addition consolidated via Cold Isostatic Pressing (CIP). 3Y-TZP was prepared by slip casting. Another batch of samples was fabricated via slip casting with the addition of 5 wt% of ceria, followed by CIP. All samples were sintered at 1600 °C. Results showed that the density and hardness of Y-TZP increased with the addition of ceria and use of CIP. The density increased from 91.8% to 98% of theoretical density, and the hardness increased from 10.33 GPa to 14.14 GPa. Field-emission scanning electron microscopy (FESEM) images showed that Y-TZP with ceria and consolidated via CIP had more homogenous grain structure with lower porosity. The X-ray diffraction (XRD) analysis showed that the phase was 100% tetragonal for both materials. Ceria addition consolidated via CIP are an effective method to improve the mechanical properties of Y-TZP.
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influence of sintering temperature on the translucency of sintered zirconia by Cold Isostatic Pressing
Advanced Materials Research, 2014Co-Authors: Chuin Hao Chin, Andanastuti Muchtar, Noor Faeizah Amat, Mariyam Jameelah Ghazali, Norziha YahayaAbstract:Zirconia-based ceramics exhibit excellent mechanical properties and biocompatibility in dental applications. However, the production of translucent zirconia that offers resemblance to real teeth remains a challenge. This study aims to fabricate zirconia compacts by Cold Isostatic Pressing (CIP) and investigate the influence of sintering temperature on translucency, microstructure, hardness, and density of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). Zirconia stabilized with 3 mol% yttria (3Y-TZP) was pressed by uniaxial Pressing and later by CIP to produce green bodies in pellet form. Subsequently, the green bodies were sintered at different temperatures (1100 °C to 1300 °C). The specimens were then investigated in terms of translucency, density, and hardness. X-ray diffraction was also performed and the microstructure of the specimens was observed under a scanning electron microscope (SEM). Density and light transmittance tests results showed that zirconia sintered at 1200 °C exhibits the highest density (5.957 g/cm3) and light transmittance intensity. Vickers hardness test showed that higher sintering temperatures result in higher hardness of the sintered zirconia. SEM micrographs illustrate the effect of microstructural changes on the translucency of zirconia. A temperature of 1200 °C is found to be the recommended sintering temperature at which zirconia exhibiting optimum translucency and mechanical properties is produced. CIP is found to be a suitable consolidation method to produce high-density translucent zirconia.
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comparison between slip casting and Cold Isostatic Pressing for the fabrication of nanostructured zirconia
Advanced Materials Research, 2014Co-Authors: Noor Faeizah Amat, Andanastuti Muchtar, Norziha Yahaya, Mariyam Jameelah GhazaliAbstract:Consolidation of ceramic parts may be achieved by several techniques, including the slip casting and Cold Isostatic Pressing (CIP) methods. In the present work, the performances of the two methods are compared in the fabrication of nanostructured zirconia compacts for dental crown applications. First, a zirconia suspension suitable for slip casting was prepared. The rheological properties of the zirconia suspension were optimized by adding a dispersant agent and controlling the pH. Zirconia slurries were then slip-cast into a pellet. Second, another group of zirconia pellets were fabricated using uniaxial Pressing and were then Cold-Isostatically pressed. Both slip-cast and CIP samples were sintered at 1300 °C with a soaking time of 2 hrs. The mechanical properties of both samples were compared. The samples prepared by slip casting were denser compared with those prepared via CIP. Slip casting technique produced samples with 98.8% of the theoretical density, which resulted in the high Vickers hardness (11.4 GPa) of the slip-cast samples. Morphological studies revealed that the microstructures of the slip cast-sample were more homogeneous and contain no porosity. The formation of such a structure is due to the enhancement of the particle packing efficiency by slip casting as well as to the removal of larger agglomerates by colloidal processing prior to casting. As a consolidation stage, slip casting appears to be more suitable than the CIP technique in preparing reliable nanostructural ceramic parts.
Hidehiro Kamiya - One of the best experts on this subject based on the ideXlab platform.
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Densification of Alkoxide‐Derived Fine Silica Powder Compact by Ultra‐High‐Pressure Cold Isostatic Pressing
Journal of the American Ceramic Society, 2005Co-Authors: Hidehiro Kamiya, Hisao Suzuki, Daisuke Kato, Genji JimboAbstract:Powder compacts of alkoxide-derived fine silica powders were consolidated into a highly dense and uniform structure by ultra-high-pressure Cold Isostatic Pressing of granules with controlled structure. The diameters of spherical and nearly monosized amorphous silica particles, prepared from metal alkoxide, were successfully controlled in the range of 9 to 760 nm by varying the concentration of ammonia. Close-packed granules of these powders were produced by spray drying. These powders were Isostatically pressed up to 1 GPa at room temperature. Although the average particle diameter was less than 100 nm, the maximum relative density of the compacts was more than 78% of theoretical density. The optimum particle size to obtain highly dense compacts was in the range of 30 to 300 nm at 1 GPa. Furthermore, the ratio of mode pore diameter in these compacts to particle diameter was less than 0.155, which corresponded to the minimum ratio of calculated three-particle pore channel radii for hexagonal close packing. Viscous deformation of particles under ultra-high Isostatic pressure played an important role in the densification of the compacts.
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Densification of sol-gel-derived mullite ceramics after Cold Isostatic Pressing up to 1 GPa
Journal of the American Ceramic Society, 2005Co-Authors: Hidehiro Kamiya, Takahiro Ichikawa, Hisao Suzuki, Masayuki HorioAbstract:Molecular-designed ultrafine mullite precursor powders with a stoichiometric composition were prepared by copolymerization of alkoxides. The precursor powders were calcined in the range from 800° to 1200°C and consolidated by ultra-high-pressure Cold Isostatic Pressing up to 1 GPa. Ultrahigh Isostatic pressure of 1 GPa led to a closed packing structure in the green compacts. Interaggregate pores in the green compacts were collapsed by the ultrahigh Cold Isostatic pressure to reduce the pore size below 6 nm. As a result, the maximum density of the green compacts reached 70% of theoretical. These closely packed green compacts of precursor powders with a stoichiometric composition and calcined at relatively low temperatures could be sintered to >95% of theoretical at 1500°C. Relatively low-temperature sintering below the liquid formation temperature resulted in fine microstructure of the resultant mullite ceramic with a grain size below 300 nm.
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processing of mullite ceramic from alkoxide derived silica and colloidal alumina with ultra high Cold Isostatic Pressing
Journal of The European Ceramic Society, 1998Co-Authors: Hidehiro Kamiya, Masayuki Horio, Yoshio Suzuki, Hisao SuzukiAbstract:Abstract Ultra-fine mullite precursor powders were prepared from the uniform mixtures of ultra-fine γ-Al 2 O 3 and alkoxide-derived SiO 2 powders. Two kinds of mixing methods—ball milling and stirring—were used to change the level of mixing. The ball milling method attained the more uniform mixing state to form single phase mullite after the calcination of mixed powder at 1300 °C. Green compacts of the calcined precursor powders were consolidated by ultra-high Cold Isostatic Pressing up to 1 GPa. Since ultra-high Isostatic pressure offers the close packing structure in the green compacts, the maximum relative density of the green compacts reached about 60% of theoretical in which the inter-aggregate pore was collapsed to reduced the pore size below 6 nm. These closely and uniformly packed green compacts could be sintered almost full density of a stoichiometric mullite ceramic without glassy and other crystalline phase. Maximum density of the compacts reached more than 96% of theoretical by the pressureless sintering even below liquid formation temperature. As a result, dense mullite ceramic with a stoichiometric composition and fine microstructure composed of grains below 0.5 μm could be sintered at relatively low temperatures.
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densification of alkoxide derived fine silica powder compact by ultra high pressure Cold Isostatic Pressing
Journal of the American Ceramic Society, 1993Co-Authors: Hidehiro Kamiya, Hisao Suzuki, Daisuke Kato, Genji JimboAbstract:Powder compacts of alkoxide-derived fine silica powders were consolidated into a highly dense and uniform structure by ultra-high-pressure Cold Isostatic Pressing of granules with controlled structure. The diameters of spherical and nearly monosized amorphous silica particles, prepared from metal alkoxide, were successfully controlled in the range of 9 to 760 nm by varying the concentration of ammonia. Close-packed granules of these powders were produced by spray drying. These powders were Isostatically pressed up to 1 GPa at room temperature. Although the average particle diameter was less than 100 nm, the maximum relative density of the compacts was more than 78% of theoretical density. The optimum particle size to obtain highly dense compacts was in the range of 30 to 300 nm at 1 GPa. Furthermore, the ratio of mode pore diameter in these compacts to particle diameter was less than 0.155, which corresponded to the minimum ratio of calculated three-particle pore channel radii for hexagonal close packing. Viscous deformation of particles under ultra-high Isostatic pressure played an important role in the densification of the compacts.
Hisao Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Densification of Alkoxide‐Derived Fine Silica Powder Compact by Ultra‐High‐Pressure Cold Isostatic Pressing
Journal of the American Ceramic Society, 2005Co-Authors: Hidehiro Kamiya, Hisao Suzuki, Daisuke Kato, Genji JimboAbstract:Powder compacts of alkoxide-derived fine silica powders were consolidated into a highly dense and uniform structure by ultra-high-pressure Cold Isostatic Pressing of granules with controlled structure. The diameters of spherical and nearly monosized amorphous silica particles, prepared from metal alkoxide, were successfully controlled in the range of 9 to 760 nm by varying the concentration of ammonia. Close-packed granules of these powders were produced by spray drying. These powders were Isostatically pressed up to 1 GPa at room temperature. Although the average particle diameter was less than 100 nm, the maximum relative density of the compacts was more than 78% of theoretical density. The optimum particle size to obtain highly dense compacts was in the range of 30 to 300 nm at 1 GPa. Furthermore, the ratio of mode pore diameter in these compacts to particle diameter was less than 0.155, which corresponded to the minimum ratio of calculated three-particle pore channel radii for hexagonal close packing. Viscous deformation of particles under ultra-high Isostatic pressure played an important role in the densification of the compacts.
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Densification of sol-gel-derived mullite ceramics after Cold Isostatic Pressing up to 1 GPa
Journal of the American Ceramic Society, 2005Co-Authors: Hidehiro Kamiya, Takahiro Ichikawa, Hisao Suzuki, Masayuki HorioAbstract:Molecular-designed ultrafine mullite precursor powders with a stoichiometric composition were prepared by copolymerization of alkoxides. The precursor powders were calcined in the range from 800° to 1200°C and consolidated by ultra-high-pressure Cold Isostatic Pressing up to 1 GPa. Ultrahigh Isostatic pressure of 1 GPa led to a closed packing structure in the green compacts. Interaggregate pores in the green compacts were collapsed by the ultrahigh Cold Isostatic pressure to reduce the pore size below 6 nm. As a result, the maximum density of the green compacts reached 70% of theoretical. These closely packed green compacts of precursor powders with a stoichiometric composition and calcined at relatively low temperatures could be sintered to >95% of theoretical at 1500°C. Relatively low-temperature sintering below the liquid formation temperature resulted in fine microstructure of the resultant mullite ceramic with a grain size below 300 nm.
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processing of mullite ceramic from alkoxide derived silica and colloidal alumina with ultra high Cold Isostatic Pressing
Journal of The European Ceramic Society, 1998Co-Authors: Hidehiro Kamiya, Masayuki Horio, Yoshio Suzuki, Hisao SuzukiAbstract:Abstract Ultra-fine mullite precursor powders were prepared from the uniform mixtures of ultra-fine γ-Al 2 O 3 and alkoxide-derived SiO 2 powders. Two kinds of mixing methods—ball milling and stirring—were used to change the level of mixing. The ball milling method attained the more uniform mixing state to form single phase mullite after the calcination of mixed powder at 1300 °C. Green compacts of the calcined precursor powders were consolidated by ultra-high Cold Isostatic Pressing up to 1 GPa. Since ultra-high Isostatic pressure offers the close packing structure in the green compacts, the maximum relative density of the green compacts reached about 60% of theoretical in which the inter-aggregate pore was collapsed to reduced the pore size below 6 nm. These closely and uniformly packed green compacts could be sintered almost full density of a stoichiometric mullite ceramic without glassy and other crystalline phase. Maximum density of the compacts reached more than 96% of theoretical by the pressureless sintering even below liquid formation temperature. As a result, dense mullite ceramic with a stoichiometric composition and fine microstructure composed of grains below 0.5 μm could be sintered at relatively low temperatures.
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densification of alkoxide derived fine silica powder compact by ultra high pressure Cold Isostatic Pressing
Journal of the American Ceramic Society, 1993Co-Authors: Hidehiro Kamiya, Hisao Suzuki, Daisuke Kato, Genji JimboAbstract:Powder compacts of alkoxide-derived fine silica powders were consolidated into a highly dense and uniform structure by ultra-high-pressure Cold Isostatic Pressing of granules with controlled structure. The diameters of spherical and nearly monosized amorphous silica particles, prepared from metal alkoxide, were successfully controlled in the range of 9 to 760 nm by varying the concentration of ammonia. Close-packed granules of these powders were produced by spray drying. These powders were Isostatically pressed up to 1 GPa at room temperature. Although the average particle diameter was less than 100 nm, the maximum relative density of the compacts was more than 78% of theoretical density. The optimum particle size to obtain highly dense compacts was in the range of 30 to 300 nm at 1 GPa. Furthermore, the ratio of mode pore diameter in these compacts to particle diameter was less than 0.155, which corresponded to the minimum ratio of calculated three-particle pore channel radii for hexagonal close packing. Viscous deformation of particles under ultra-high Isostatic pressure played an important role in the densification of the compacts.
G. Ya. Akimov - One of the best experts on this subject based on the ideXlab platform.
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Specific physical properties of nanocrystalline (La0.65Sr0.35)0.8Mn1.2O3 ± Δ samples obtained by Cold Isostatic Pressing
Physics of the Solid State, 2009Co-Authors: G. Ya. Akimov, S. Yu. Prylypko, Yu. F. Revenko, V.m. TimchenkoAbstract:Single-phase powders of manganites (La0.65Sr0.35)0.8Mn1.2O3 ± Δ with average crystallite sizes of 30, 50, and 500 nm were produced by co-precipitation. The samples studied were obtained by Cold Isostatic Pressing of powders at a pressure of 1 GPa without subsequent sintering. It is shown that the size of particles has a significant effect on the electromagnetic properties of the manganite samples. As the crystallite size decreases, the electrical resistance and coercive force increase and the tunneling magnetoresistance of the samples and the Curie temperature decrease.
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Effect of Cold Isostatic Pressing on the synthesis and particle size of lanthanum manganate
Powder Metallurgy and Metal Ceramics, 2008Co-Authors: S. Yu. Prilipko, V.m. Timchenko, G. Ya. Akimov, V. I. TkachAbstract:X-ray diffraction and thermogravimetry are used to examine the influence of temperature and Cold Isostatic Pressing on the synthesis and crystalline growth of lanthanum manganate. Coprecipitated {ie284-01} samples compacted under different pressures before synthesis are examined. It is shown that Pressing promotes synthesis, decreases its temperature, and retards crystalline growth. The results demonstrate that Cold Isostatic Pressing is promising for obtaining nanocrystalline manganates.
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Effect of Hydroxide Calcination Temperature, Cold Isostatic Pressing (CIP) Pressure, and Sintering Temperature on Properties of ZrO2 + 3 mol.% Y2O3 Ceramic
Refractories and Industrial Ceramics, 2002Co-Authors: G. Ya. Akimov, V.m. Timchenko, É. V. ChaikaAbstract:ZrO_2 + 3 mol.% Y_2O_3 ceramic specimens are prepared by sintering, at 1500 and 1600°C, preforms molded from calcined hydroxide powders at 850 and 750°C using a Cold Isostatic Pressing (CIP) technique. Bending strength and density measured as a function of the CIP pressure is shown to be quite different for specimens sintered at the two temperatures. Implications of this different behavior are discussed.
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Formation of properties of ceramics from MgO powders obtained with the use of Cold Isostatic Pressing
Refractories and Industrial Ceramics, 1999Co-Authors: G. Ya. Akimov, V. V. StorozhAbstract:Results of a study of the effect of Cold Isostatic Pressing (CIP) of granulated MgO powder under a pressure of 0.3 and 2.0 GPa on the properties of compacts and ceramics are presented. It is shown that the density and strength of the compacts are 65 and 80%, 10 and 55 MPa after CIP conducted at a pressure of 0.3 and 2.0 GPa, respectively. The ceramics was sintered at 1600‡C for 1,2,4, and 8 h. At all sintering times the density and strength of the ceramics is higher when the powder has been compacted under a pressure of 2.0 GPa.
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Cold Isostatic Pressing as a method for fabricating ceramic products with high physicomechanical properties
Refractories and Industrial Ceramics, 1998Co-Authors: G. Ya. AkimovAbstract:The experimental results published by the author and his co-workers in 24 earlier works and novel original data are analyzed. It is shown that the process of Cold Isostatic Pressing (CIP) occurs with mechanical activation of the powder particles due to their self-deformation with a simultaneous self-compaction of the semiproduct. The CIP process of powders or traditionally shaped preforms is shown to elevate their density and activate the sintering processes but diminish their sintering temperature and increase the density, strength and crack resistance of the ceramics. The use of surface-active substances (SAS) in CIP is shown to elevate the level of the physicomechanical properties of the ceramics. The basic concepts of controlling the properties of ceramics by choosing the appropriate dispersity of the powder, the CIP pressure, the SAS, and the sintering regime are presented.
V.m. Timchenko - One of the best experts on this subject based on the ideXlab platform.
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Specific physical properties of nanocrystalline (La0.65Sr0.35)0.8Mn1.2O3 ± Δ samples obtained by Cold Isostatic Pressing
Physics of the Solid State, 2009Co-Authors: G. Ya. Akimov, S. Yu. Prylypko, Yu. F. Revenko, V.m. TimchenkoAbstract:Single-phase powders of manganites (La0.65Sr0.35)0.8Mn1.2O3 ± Δ with average crystallite sizes of 30, 50, and 500 nm were produced by co-precipitation. The samples studied were obtained by Cold Isostatic Pressing of powders at a pressure of 1 GPa without subsequent sintering. It is shown that the size of particles has a significant effect on the electromagnetic properties of the manganite samples. As the crystallite size decreases, the electrical resistance and coercive force increase and the tunneling magnetoresistance of the samples and the Curie temperature decrease.
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specific physical properties of nanocrystalline la0 65sr0 35 0 8mn1 2o3 δ samples obtained by Cold Isostatic Pressing
Physics of the Solid State, 2009Co-Authors: Ya G Akimov, Yu. F. Revenko, Yu S Prylypko, V.m. TimchenkoAbstract:Single-phase powders of manganites (La0.65Sr0.35)0.8Mn1.2O3 ± Δ with average crystallite sizes of 30, 50, and 500 nm were produced by co-precipitation. The samples studied were obtained by Cold Isostatic Pressing of powders at a pressure of 1 GPa without subsequent sintering. It is shown that the size of particles has a significant effect on the electromagnetic properties of the manganite samples. As the crystallite size decreases, the electrical resistance and coercive force increase and the tunneling magnetoresistance of the samples and the Curie temperature decrease.
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Effect of Cold Isostatic Pressing on the synthesis and particle size of lanthanum manganate
Powder Metallurgy and Metal Ceramics, 2008Co-Authors: S. Yu. Prilipko, V.m. Timchenko, G. Ya. Akimov, V. I. TkachAbstract:X-ray diffraction and thermogravimetry are used to examine the influence of temperature and Cold Isostatic Pressing on the synthesis and crystalline growth of lanthanum manganate. Coprecipitated {ie284-01} samples compacted under different pressures before synthesis are examined. It is shown that Pressing promotes synthesis, decreases its temperature, and retards crystalline growth. The results demonstrate that Cold Isostatic Pressing is promising for obtaining nanocrystalline manganates.
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Effect of Hydroxide Calcination Temperature, Cold Isostatic Pressing (CIP) Pressure, and Sintering Temperature on Properties of ZrO2 + 3 mol.% Y2O3 Ceramic
Refractories and Industrial Ceramics, 2002Co-Authors: G. Ya. Akimov, V.m. Timchenko, É. V. ChaikaAbstract:ZrO_2 + 3 mol.% Y_2O_3 ceramic specimens are prepared by sintering, at 1500 and 1600°C, preforms molded from calcined hydroxide powders at 850 and 750°C using a Cold Isostatic Pressing (CIP) technique. Bending strength and density measured as a function of the CIP pressure is shown to be quite different for specimens sintered at the two temperatures. Implications of this different behavior are discussed.
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Cold Isostatic Pressing as a method for fabricating high-strength ceramic materials based on ZrO_2
Refractories and Industrial Ceramics, 1997Co-Authors: I. Yu. Prokhorov, V.m. Timchenko, G. Ya. Akimov, A. D. Vasil’evAbstract:High-strength ceramic materials fabricated with the use of Cold Isostatic Pressing (CIP) at ≤0.8 GPa and sintering by different regimes from yttria-stabilized zirconia produced by leading foreign and Ukrainian firms are described. All the materials exhibit two peaks of mechanical properties, one at a low CIP pressure (0.1–0.3 GPa) attributable to destabilization of the press-powder and characterizing the stability of the material as a whole and the other at a high CIP pressure (above 0.6 GPa) attributable to attainment of close packing of the particles. In accordance with the set of standard properties the materials can be classified into two types, namely, intermediate-strength ones with an ultimate bending strength of 700–900 MPa, K _1c ranging from 7 to 12 MPa·m^1/2, a density of about 6 g/cm^2, and an optimum CIP pressure of 0.2–0.3 GPa (the first peak) and high-strength materials with an ultimate bending strength of about 1200 MPa, K _Ic ranging from 6 to 9 MPa·m^1/2, a density of about 6.1 g/cm^3, and an optimum CIP pressure of 0.1 GPa. The intermediate type comprises the majority of domestic materials and some foreign ones and is characterized by higher stability and crack resistance. The high-strength type comprises mainly foreign materials with high strength and lower stability.