Papers by Keyword: 3Y-TZP

Abstract: Water-based suspensions from commercial Tetragonal stabilized zirconia (3Y-TZP) were produced and characterized with different contents of solids and two different dispersants. According to zeta potential measurements, 3Y-TZP particles showed basic surface characteristics and IEP of around 9 when in aqueous media. The critical volume fraction of solids was about 79.6 wt%, which hindered the processing of more concentrated slurries. Rheological measurements confirmed that well dispersed slurries could be obtained with solid content as high as 79.6 wt.%. The results showed that Triton X-114 was an effective dispersant for preparing well stabilized 3Y-TZP suspensions for the layer-wise slurry deposition process.

Abstract: The effects of sintering temperatures on consolidation and mechanical properties of 3 mol% Y-TZP (3Y-TZP) powders were studied in this work. Samples were sintered at 1250°C to 1450°C sintering temperature in air. Throughout the sintering regime, high value of relative bulk density 99.41% of theoretical densities was obtained for the maximum sintering temperature. Maximum Young's modulus of 3Y-TZP was obtained at 1450°C and maximum fracture toughness value of 3Y-TZP was observed at the 1300°C sintering temperature. The Vickers's hardness values of 3Y-TZP also increased gradually with sintering temperature.

Abstract: This paper studies mainly the diffusion bonding of 3Y-TZP/SUS304 by using the chemical bonding method. In the bonding interface of 3Y-TZP and SUS304, the Ti-Cu powder/sheet was used as bonding materials. In bonding process, multi-alloy with Fe-Ti and Fe-Cu have been confirmed by Electron Probe Micro-Analyzer (EPMA) determination. Through the microstructure observed by AFM and SEM, bonding boundaries of 3Y-TZP/SUS304 by Ti-Cu powder/sheet had good formation. The distribution of the residual stress on near interface was measured by XRD method. By using of these results, the mechanism of the ceramic and stainless steel was discussed.

Abstract: The effects of an anionic polyelectrolyte on the dispersion of 3Y-TZP suspensions in aqueous medium have been systematically investigated. The results of rheological experiments show that at CD = 0.5 wt% (CD : dispersant concentration), the dispersant could afford well-dispersed 3Y-TZP suspensions over a wider range of solids loading, owing to the stronger electrostatic repulsion between particles resulting from the monolayer coverage of the particle. But as CD ≤ 0.5 wt% or CD ≥0.5 wt%, the stable 3Y-TZP suspensions can only be achieved at a relatively lower solids loading, which are ascribed to the reduced repulsion barrier between particles owing to the lower ζ values of particles and the higher ionic strength in the system, respectively.

Abstract: 3Y-TZP powder has been successfully synthesized by gel solid-state method. The structural phases of powder particles were analyzed by X-ray diffraction and the morphology was analyzed by scanning electron microscopy. The average size of grains was 230 nm. The sintering behavior, mechanical properties and microstructure of 3Y-TZP ceramics sintered by this powder were investigated. The experiment results showed that the mechanical properties of ceramics were excellent.

Abstract: The influence of conductivity of supernatant of 3Y-TZP powder on the sintering properties of its ceramics is evaluated. It is found that the conductivity of supernatant is helpful for the determination of the sintering activities. The sintering properties of 3Y-TZP ceramics are improved with the increase of the conductivity of supernatant. It is attributed to a large amount of unsaturated states in the powder.

Abstract: This paper is mainly a study the diffusion bonding of 3Y-TZP/SUS440 by using the chemical bonding method. In the bonding interface of 3Y-TZP and SUS440, the Ti-Cu (brass) powder/sheet was used as bonding materials. After bonding process, multi-alloy field with Fe-Ti and Fe-Cu have been confirmed by EPMA determination. Through the microstructure observed by AFM and SEM, bonding boundaries of 3Y-TZP/SUS440 by Ti-Cu powder/sheet had good formation. The distribution of the residual stress on near interface was measured by XRD method. By using of these results, the mechanism of the ceramic and stainless steel was discussed.

Abstract: Layered hydroxyapatite (HA) based ceramic composites consisting of a strong ceramic composite core, 3 mol% yttrium stabilized zirconia (3Y-TZP) with 30 or 40 vol% HA, and a HA-rich porous coating were fabricated using a coating deposition and co-sintering process in the present study. The aim is to develop HA-based bio-ceramic composites that retain the bio-compatibility of HA and the preferred scaffold structure, but have much improved structural properties required for implants. Two different coating techniques, sol-gel derive HA coating and HA solution coating, have been used to deposit the HA coating on the strong HA-containing 3Y-TZP core, which has been pre-sintered at 900°C and has a green-machined surface finish. The upper limit for the final sintering of the layered ceramic composites is set at 1,350°C based on the individual sintering properties of HA and 3Y-TZP. SEM observations have been conducted on the coating surface, sectioned surface of coating and substrate/core to characterize the microstructures of coating and substrate and their interface. Preliminary mechanical tests and XRD tests are also performed to characterise the structural properties at different temperatures.

Abstract: 3 mol% yttric(Y₂O₃)-stabilized tetragonal zirconia ( denoted as: 3Y-TZP) powders were synthesized by the reaction of Zr(CO₃)₂·nH₂O,Y₂(C₂O₄)₃·nH₂O,H₂C₂O₄·2H₂Oand H₄C₂O₂-C₂H₅OH mixed via stirring ball milling. The curve of decomposition of precursors was studied according to differential thermal analysis and thermogravimetry (DTA-TG). The 3Y-TZP powders were confirmed by characterization of XRD, TEM and BET. These results shown that the size of the 3Y-TZP powders were in the range of about 18nm-28nm with good dispersion and the main phase of target production was tetragonal phase. When calcining temperature and holding time was higher, the size of particles grown up and the tetragonal phase volume fraction decrease gradually. And the calcining temperature has more significant effect.

Abstract: Thermal stability and wear resistance of nanoceramic materials are excellent, so it is an ideal die material and has become one of the increasingly important topics in the field of die research. A new 3Y-TZP nanocomposite die material was prepared with hot pressing technique by using 3Y-TZP, CeO2, Al2O3 and nanometer sized TiC as raw materials. Effects of CeO2 on the mechanical property and microstructure of 3Y-TZP nanocomposite die material were investigated. The addition of CeO2 has obvious effect on the flexural strength and fracture toughness. When the content of CeO2 is 2mol%, the fracture toughness of the composite material reaches 11.22MPa•m1/2. With the increase of CeO2 content, the fracture toughness becomes lower, the flexural strength and hardness first increase and then decrease. When the CeO2 content is 6mol%, the maximum flexural strength reaches 866MPa. The reason for the improvement of mechanical property can be attributed to the effect of CeO2 on the phase transformation of t-ZrO2 and microstructure and the resulted phase transformation toughening mechanism.