Densification behaviour and properties of manganese oxide doped Y-TZP ceramics (original) (raw)
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Sintering and Ageing Properties of Manganese Doped Y-TZP Ceramics
The sinterability of 3 mol% yttria-tetragonal zirconia polycrystals (Y-TZP) containing small amounts of manganese oxide (MnO2) as sintering aid was investigated over the temperature range of 1250°C to 1500°C. Sintered samples were evaluated to determine bulk density, Young’s modulus, Vickers hardness and fracture toughness. In addition, the tetragonal phase stability of selected samples was evaluated by subjecting the samples to hydrothermal ageing in superheated steam at 180°C/10 bar for periods up to 525 hours. The research showed that the addition of MnO2, particularly ³ 0.3 wt%, was effective in aiding densification and improving the matrix stiffness and hardness when compared to the undoped Y-TZP sintered at temperatures below 1350°C. On the other hand, the fracture toughness of Y-TZP was unaffected by MnO2 addition except for the 1 wt% MnO2-doped Y-TZP samples sintered above 1400°C. The hydrothermal ageing resistance of Y-TZP was significantly improved with the additions of Mn...
The Influence of Manganese Oxide on the Densification and Mechanical Properties of 3Y-TZP Ceramics
Applied Science and Engineering Progress
With outstanding integration of mechanical performances and biocompatibility, 3 mol% of yttria stabilised tetragonal zirconia polycrystals (3Y-TZP) ceramic are extensively fabricated as biomedical implants. Conventional sintering (CS) was generally employed to produce 3Y-TZP bodies with promising densification, which resulted in grain coarsening and mechanical properties deterioration due to elevated sintering temperatures (> 1500°C). The main weakness of 3Y-TZP ceramic is the spontaneous tetragonal to monoclinic phase transformation under humid environment, which is known as low-temperature degradation (LTD). In present work, undoped and MnO 2 (0.3 and 0.5 wt%) doped 3Y-TZP green bodies were prepared and subjected to CS at 1200-1500°C for an hour of dwelling time. It was found that the optimum concentration of MnO 2 dopant was 0.5 wt%. Reasonable toughness values of 5-7 MPa.m 1/2 revealed the tetragonal phase stability of 3Y-TZP grains was not altered by doping of MnO 2. Moreover, outstanding density level of > 96% of 0.5 wt% MnO 2 doped 3Y-TZP ceramics demonstrated the superb Young's modulus of > 200 GPa and Vicker's hardness of >13 GPa. Fabrication of 3Y-TZP by doping MnO 2 had reduced the total processing time by ~ 9% and sintering temperature by up to 150°C when compared to undoped 3Y-TZP ceramics sintered at 1400°C.
The sintering of yttria-tetragonal zirconia polycrystals (Y-TZP) is commonly carried at a predefined temperature using a long holding time of 2 hours. This often has resulted in grain coarsening which affects the mechanical properties of the sintered body and low temperature degradation (LTD) behaviour of the ceramic when exposed to moist environment. In this research, the effect of using a short holding time of 1 min. during sintering coupled with small amounts (0.5 and 1 wt%) of manganese oxide, MnO2 as dopant on the mechanical properties and LTD behaviour of 3 mol% Y-TZP were investigated. The results showed that the mechanical properties improved significantly with the addition of 0.5 wt% MnO2 for the 1-min. and 12-min. holding time samples when compared to 2 hours holding time sintered at the same temperature of 1350 degrees C. Nevertheless, regardless of the holding time employed, the 1 wt% MnO2 addition was not effective in improving the mechanical properties and ageing resistance of Y-TZP ceramic. Link to Full-Text Articles : http://jcpr.kbs-lab.co.kr/file/JCPR\_vol.16\_2015/JCPR16-2/\_032014-099\_193-198.pdf
Influence of sintering profile on the mechanical properties of manganese oxide doped 3Y-TZP
IOP Conference Series: Earth and Environmental Science, 2020
Zirconia ceramic has been identified as one of the advanced ceramic material with great mechanical properties which is used as engineering and implant materials. However, the great potential of the ceramic is hindered by low temperature degradation (LTD) where the ceramic experiencing t-m phase transformation that weakens the properties of 3Y-TZP in the presence of moisture. Two-step sintering was found to be effective in producing fully resistance 3Y-TZY but very long holding time is required. Manganese Oxide (MnO2) is reported as good densification aid at low sintering temperature for 3Y-TZP but the LTD issue is not fully resolved. In this study, the effects of different sintering profiles and dwell time on 3Y-TZP added with 0.5 wt.% of MnO2 were studied in order to improve the resistance towards LTD without affecting the intrinsic properties of the ceramic. The effects of adding 0.5 wt.% of manganese oxide (MnO2) into 3 mol% yttria stabilized tetragonal zirconia polycrystals (3Y-...
Journal of Materials Engineering and Performance, 2014
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Your article is protected by copyright and all rights are held exclusively by ASM International. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to selfarchive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
The Role of Magnesium Oxide on the Mechanical Properties of Y-TZP Ceramic
2014
An investigation has been carried out into the effects of magnesium oxide additions in the 0.1 to 1.0 wt% range on the properties and behavior of Y-TZP. All samples have been sintered over the temperature range of 1200°C to 1500°C with a ramp rate of 10°C/ minute and 2 hours of holding time. Upon reaching the peak temperature, the sintering temperature was immediately brought down to a holding temperature of 1250°C and held for 4 hours. Green samples were compacted by uniaxial pressing and cold isostatically pressed at 200 MPa. The results show that the addition of 0.3 wt% MgO was effective in aiding densification (~99% theoretical density). The MgO addition to the Y-TZP matrix also displayed an increment of flexural strength as the content increased. Bulk density and Vickers hardness show the beneficial effect of MgO in aiding the densification of Y-TZP ceramics.
Effect Of Sintering Profiles On The Properties And Ageing Resistance Of Y-Tzp Ceramic
International Journal of Automotive and Mechanical Engineering, 2011
"A commercially available Y-TZP ceramic powder was fabricated under four different sintering profiles in order to investigate the effects of conventional single-stage sintering (SSS) with dwell times of 1 min and 2 h, respectively, compared with two-stage sintering (TSS), on the physical and mechanical properties of Y-TZP. Sintering was performed up to 1400°C at a ramp rate of 10°C/min. It was revealed that samples sintered via TSS yielded better properties than the SSS samples sintered at 1400°C using a dwell time of 2 h. In the hydrothermal ageing test, TSS samples did not undergo low-temperature degradation via the tetragonal to monoclinic phase transformation. Nevertheless, it was found by XRD analysis that Y-TZP ceramics sintered by the SSS method using a short dwell time of 1 min were effective in maintaining tetragonal phase stability after 50 h of exposure to superheated steam conditions. http://www.doaj.org/doaj?currentYear=2013&id=1173095&go=1&func=abstract&fromYear=&toYear=
Evaluation of Nd2O5 Doped Y-tzp Using two step Sintering Method
2014
Background: An investigation was carried out to evaluate the mechanical properties of Nd2O5 doped 3Y-TZP using the two-step sintering method. A pressure less sintering technique was used to sinter samples over a temperature range of 1300°C to 1500°C with a ramp rate of 10°C/ minute and a holding time of 2 hours. Sintered bodies were tested to determine the bulk density, hardness, Young's Modulus and fracture toughness. The results show that bulk density, hardness and fracture toughness was enhanced by the addition of 0.3 wt. % Nd2O5. The two step sintering method was also prominent in improving Young's Modulus. An increasing trend is seen from 0.3 wt. % up to 0.5 wt. % addition of Nd2O5.
Ceramics International, 2012
3 mol% Y 2 O 3-stabilized zirconia nanopowders were fabricated using various sintering techniques; conventional sintering (CS) and non-conventional sintering such as microwave (MW) and pulsed electric current-assisted-sintering (PECS) at 1300 ºC and 1400 ºC. A considerable difference in the densification behaviour between conventional and non-conventional sintered specimens was observed. The MW materials attain a *Manuscript Click here to view linked References bulk density 99.4% theoretical density (t.d.) at 1300 ºC, while the CS materials attain only 92.5% t.d. and PECS 98.7% t.d. Detailed microstructural evaluation indicated that a low temperature densification leading to finer grain sizes (135 nm) could be achieved by PECS followed by MW with an average sintered grain size of 188 nm and CS 225 nm. It is believed that the high heating rate and effective particle packing are responsible for the improvements in these properties.