The Effect of Sintering Profiles on Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering

2021 ◽  
Vol 904 ◽  
pp. 174-180
Author(s):  
Teow Hsien Loong ◽  
Sivakumar Sivanesan ◽  
Se Yong Eh Noum
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bulk Density ◽  
Young’S Modulus ◽  
Heating Rate ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Holding Time ◽  
Two Stage ◽  
Zirconia Toughened Alumina

The effects of sintering profiles on the Zirconia Toughened Alumina (ZTA) composite containing 0 vol% Y-TZP (pure alumina) to 20 vol% Y-TZP content prepared by a sintering method known as two-stage sintering were investigated. The heating rate was set between 10°C/min to 20°C/min, T1 set between 1400°C to 1500°C, T2 at 1350°C and holding time was set at 12 hours. The samples’ microstructural properties and mechanical properties, including bulk density, Vickers hardness, Young’s modulus and fracture toughness, were evaluated. Based on the data obtained, the ZTA composites with 10 vol% Y-TZP sintered at a heating rate of 10°C/min and holding time of 12 hours were able to achieve mechanical properties requirements set by the industry standard. In addition, the maximum ZTA composite’s bulk density was recorded to be above 90% T.D, while the Vickers hardness of the composite was recorded to be exceeding 17 GPa. The ZTA composite also recorded maximum Young’s modulus exceeding 380 GPa and fracture toughness above 6 MPam1/2.

Densification Behaviour and Mechanical Properties on MgO Doped Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering

2021 ◽  
Vol 1030 ◽  
pp. 3-10
Author(s):  
Teow Hsien Loong ◽  
Ananthan Soosai ◽  
Suresh Muniandy
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Total Hip Arthroplasty ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Two Stage ◽  
Positive Effect ◽  
Zirconia Toughened Alumina

The effect of doping small amounts of Magnesium Oxide ranging between 0 to 1 vol% on Zirconia Toughened Alumina (ZTA) composites which is one of main biomaterial used for production of total hip arthroplasty were investigated. The samples were produced via conventional two-stage sintering with T1 varies between 1450°C and 1550°C with heating rate of 20°C/min. The samples were then rapid cooled to T2 set at 1400°C with holding time of 12 hours. The microstructural and mechanical properties of the two-stage sintered ZTA are then investigated to determine the feasibility of MgO addition. Combination of two-stage sintering at T1 above 1500 and also small amount of MgO up to 0.5 vol% were shown to have positive effect on ZTA which exhibited improvement on its grain size, mechanical properties such as Vickers hardness, Young’s modulus and fracture toughness compared to undoped ZTA composites. The sample with 0.5 vol% MgO addition sintered at T1 of 1500°C and T2 1400°C was able to achieve Vickers hardness of 19.6 GPa, Young’s modulus of 408 GPa and fracture toughness of 6.8 MPam1/2 without significant grain growth compared to undoped ZTA composites.

Effect of Temperature and Holding Time on Zirconia Toughened Alumina (ZTA) Prepared by Two-Stage Sintering

2021 ◽  
Vol 1030 ◽  
pp. 11-18
Author(s):  
Teow Hsien Loong ◽  
Ananthan Soosai ◽  
Suresh Muniandy
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Sintering Temperature ◽  
Young's Modulus ◽  
Holding Time ◽  
Effect Of Temperature ◽  
Two Stage ◽  
Pinning Effect ◽  
Zirconia Toughened Alumina

The microstructure and mechanical properties of Zirconia Toughened Alumina (ZTA) produced via two-stage sintering at various sintering temperature of T1 and T2 in addition to effect of various holding time were investigated. T1 temperature was set between the range of 1400°C to 1500°C with a heating rate of 20°C/min. The samples were then sintered at T2 ranging from 1350°C to 1400°C followed by various holding time between 2 hours to 12 hours. The sintered samples’ microstructural properties, bulk density, hardness (Vickers hardness), elastic modulus (Young’s modulus) and fracture toughness (K1C) were then determined. Compared to standard holding time of two-stage sintering which is 12 hours, results show that ZTA produced via two-stage sintering with shorter holding time of 4 hours with T1 set at 1500°C and T2 of 1450°C are capable of achieving full densification. In addition, the same sample were also able to achieve hardness up to 19 GPa, Young’s modulus of 390 GPa and fracture toughness of 6.1 MPam1/2. The improvement in mechanical properties can be mainly attributed to the absent of surface diffusion at T2 above 1400°C and also presence of Y-TZP which contributed to lower grain growth due to the pinning effect.

Two-Stage Sintering of Alumina-Y-TZP (Al2O3/Y-TZP) Composites

2019 ◽  
Vol 814 ◽  
pp. 12-18 ◽  
Author(s):  
Sivakumar Sivanesan ◽  
Teow Hsien Loong ◽  
Satesh Namasivayam ◽  
Mohammad Hosseini Fouladi
Keyword(s):  
Fracture Toughness ◽  
Young’S Modulus ◽  
Heating Rate ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Two Stage ◽  
Dwelling Time ◽  
Microstructure Density

Alumina-Y-TZP composites between 0 to 25 vol% Y-TZP content produced via conventional two-stage sintering with T1 ranging between 1400°C and 1550°C, heating rate of 20°C/min, followed by T2 of 1350°C and 12 hours dwelling time. The microstructure, density, Vickers hardness (HV), Young’s modulus (E) and fracture toughness (KIC) of the sintered samples were then evaluated. It is observed that all samples up to 10 vol% Y-TZP achieved > 98% T.D. as the T1 increases. Samples with Y-TZP content above 10 vol% resulted in a significant decrease in density and hardness. Samples with ≤ 10 vol% Y-TZP sintered at T1 of 1450°C was able to achieve density > 98% T.D., Vickers hardness > 18 GPa and Young’s modulus > 380 GPa and fracture toughness > 6 MPam1/2 when compared to pure Al2O3 ceramics.

scholarly journals Effect of Graphene-Oxide Addition on the Microstructure and Mechanical Properties of Two-Stage Sintered Zirconia-Toughened Alumina (ZTA) Composites

2021 ◽  
Vol 335 ◽  
pp. 03019
Author(s):  
Hsien Loong Teow ◽  
Sivakumar Sivanesan ◽  
Se Yong Eh Noum ◽  
Ananthan Soosai ◽  
Suresh Muniandy
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Graphene Oxide ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
High Hardness ◽  
Two Stage ◽  
Total Hip ◽  
Microstructure And Mechanical Properties ◽  
Zirconia Toughened Alumina

United Nations has estimated that 130 million people would suffer from osteoarthritis worldwide by 2050. This disease would require patients to undergo a surgery known as Total Hip Replacement (THR) which has a failure rate of approximately 1 % with a lifespan of 20 years. The biomaterials used to manufacture this total hip artroplasty are mainly made of Zirconia-Toughened Alumina. In this work, Zirconia Toughened Alumina (ZTA) composites with 10 vol% Y-TZP content were doped with small amount (0.01 to 1 wt%) of graphene oxide (GO). The GO-doped ZTA composites were produced via two-stage sintering with T1 ranging between 1400°C and 1550°C, heating rate of 20°C/min, followed by T2 of 1350°C and 12 hours holding time. The sintered ZTA samples were then evaluated on its microstructure and mechanical properties such as bulk density, Vickers hardness, Young’s modulus and fracture toughness to investigate the effect of GO addition on ZTA samples prepared via two-stage sintering. The results showed that ZTA composites containing up 0.1 wt% GO is beneficial in improving the microstructural and mechanical properties of ZTA composites prepared via two-stage sintering. The sample recorded a high hardness of up to 18.5 GPa, Young’s modulus of 406 GPa and fracture toughness of 5.8 MPam1/2 when sintered at T1 of 1450℃.

Sinterability and Mechanical Properties of MnO2-Doped Y-TZP: The Effects of Holding Time Variations

2011 ◽  
Vol 110-116 ◽  
pp. 1284-1288 ◽  
Author(s):  
Mahdi Amiriyan ◽  
Meenaloshini Satgunam ◽  
Sivanesan Sivakumar ◽  
Singh Ramesh ◽  
Ranna Tolouei
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Beneficial Effect ◽  
Bulk Density ◽  
Vickers Hardness ◽  
Time Variation ◽  
Sintering Temperature ◽  
Tetragonal Zirconia ◽  
Holding Time ◽  
Time Variations

The effect of holding time variation and sintering temperature on the mechanical properties and sinterability of yttria stabilized tetragonal zirconia doped with 1 wt. % MnO2 was investigated. Samples were sintered at 1150-1500 °C with holding times varying from 12 and 120 minutes. Comparing to the MnO2-doped Y-TZP, longer holding time resulted in enhanced densification of the undoped Y-TZP samples. In the case of MnO2-doped Y-TZP however, Bulk density, Young’s modulus, Vickers hardness and fracture toughness results show the beneficial effect of MnO2 in enhancing the densification of Y-TZP ceramics.

scholarly journals The Effect of Cerium Oxide Addition on the Properties and Behavior of Y-TZP

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
D. Ragurajan ◽  
M. Satgunam ◽  
M. Golieskardi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bulk Density ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Sintering Behavior ◽  
Optimum Level ◽  
Oxide Addition ◽  
Time Cycle ◽  
And Behavior

The effects of CeO2 addition on the sintering behavior and mechanical properties of Y-TZP have been investigated over a wide sintering regime by pressureless sintering. It has been revealed that small additions of CeO2 (0.3–1.0 wt%) to Y-TZP were beneficial in enhancing the mechanical properties and hydrothermal ageing resistance of Y-TZP. Sintered samples were used to evaluate the bulk density, Vickers’s hardness, Young’s modulus, and fracture toughness of the material. CeO2 doped Y-TZPs were sintered at relatively low temperatures (1250°C and 1350°C) retaining high bulk density (>97% of theoretical density) and high Young’s modulus (>200 GPa) without sacrificing tetragonal phase stability. The optimum level of dopant was found to be at 0.5 wt% for sintering between 1250°C and 1450°C using the standard 2 h holding time cycle, with sintered body exhibiting excellent combination of properties when compared to the undoped ceramics. In this experiment, the addition of 0.5 wt% recorded a bulk density reading of 5.9 g/cm3, Vickers hardness value of 13.2 GPa, Young’s modulus value of 211 GPa, and fracture toughness of 6.4 MPam1/2, respectively, in a temperature range of 1400–1450°C.

Densification Behavior of Nano Y-TZP Ceramics

2013 ◽  
Vol 372 ◽  
pp. 165-168 ◽  
Author(s):  
A. Norakmal ◽  
Ramesh Singh ◽  
C.Y. Tan ◽  
W.D. Teng
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bulk Density ◽  
Young’S Modulus ◽  
Sintering Temperature ◽  
Young's Modulus ◽  
Densification Behavior ◽  
Work Samples ◽  
Hardness Values

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.

scholarly journals Densification Behaviour and Mechanical Properties of Aluminium Oxide and Cerium Oxide-Doped Yttria Tetragonal Zirconia Polycrystal Ceramics Using Two-Step Sintering

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
M. Golieskardi ◽  
M. Satgunam ◽  
D. Ragurajan
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Tetragonal Zirconia ◽  
Sintering Process ◽  
Weight Percentage ◽  
Densification Behaviour ◽  
Phase Arrangement

The densification behaviour, mechanical properties, and microstructure of high-purity Al2O3 and CeO2-doped Y-TZP with different weight percentage varied from 0.3 to 1 wt% were investigated. The samples were pressed uniaxially at 200 MPa into rectangular bars and discs and pressureless-sintered at temperature ranging between 1250°C and 1450°C for 2 h while the microstructure was characterized with a scanning electron microscope (SEM). Two-step sintering process works well for temperature higher than 1400°C and it created most tetragonal phase arrangement for stable structure to delay ageing through phase transformation. The mechanical properties in terms of bulk density, Young’s modulus, Vickers hardness, and fracture toughness were also measured. The results indicate that the addition of dopants accelerated the densification parameters and reinforced and toughened the obtained bodies. The maximum values for the mechanical properties of the Al2O3 and CeO2-doped Y-TZP ceramics were 6.01, 220 GPa, 13.8 GPa, and 7 MPa for density, Young’s modulus, Vickers hardness, and fracture toughness, respectively, which are higher than those of the doped samples.

Influence of Material Composition on Mechanical Properties and Fracture Behavior of Ceramic-Metal Composites

2005 ◽  
Vol 297-300 ◽  
pp. 1516-1521 ◽  
Author(s):  
Keiichiro Tohgo ◽  
Takayuki Kawaguchi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Vickers Hardness ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Metal Phase ◽  
Metal Composites

In order to estimate distribution of mechanical properties and fracture toughness in ceramic-metal functionally graded materials (FGMs), mechanical properties and fracture behavior have been investigated on non-graded ceramics-metal composites which correspond to each region of FGMs. The materials are fabricated by powder metallurgy using partially stabilized zirconia (PSZ) and stainless steel (SUS 304). Vickers hardness, Young’s modulus and bending fracture strength were examined on smooth specimens. The Vickers hardness of the composites continuously decreases with an increase in a volume fraction of SUS 304 metal phase, while the Young’s modulus and fracture strength exhibit low values in the composites with balanced composition of each phase. This suggests that the interfacial strength between the ceramic and metal phases is very low. Fracture toughness tests are conducted by three-point-bending on rectangular specimens with a sharp edgenotch. In contrast with the Young’s modulus and fracture strength, the fracture toughness obtained for the composites increases with an increase in a volume fraction of SUS 304 metal phase. The fracture toughness of the composites is slightly lower than that obtained previously by stable crack growth in a PSZ-SUS 304 FGM. The difference in fracture toughness between the composites and FGM seems to be attributed to the residual stress created during fabrication of the FGM.

Effect of Added Cr3C2 on the Microstructure and Mechanical Properties of WC–SiC Ceramics

2015 ◽  
Vol 656-657 ◽  
pp. 33-38 ◽  
Author(s):  
Akihiro Nino ◽  
Takashi Sekine ◽  
Kazuhisa Sugawara ◽  
Shigeaki Sugiyama ◽  
Hitoshi Taimatsu
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Grain Size ◽  
Young’S Modulus ◽  
Vickers Hardness ◽  
Young's Modulus ◽  
Sic Ceramics ◽  
Phase Type ◽  
Binder Free

WC–20 mol% SiC ceramics with added Cr3C2 were sintered at 1600°C with a resistance-heated hot-pressing machine. Dense WC–SiC ceramics containing 0.1–0.9 mol% Cr3C2 were obtained. Above 1.2 mol% Cr3C2, the relative density decreased with increasing Cr3C2 content. A small amount of a Nowotny-phase type (Mo5Si3C-type) product was formed by the addition of Cr3C2, and no Cr3C2-based solid solution was found. The WC–20 mol% SiC–Cr3C2 ceramics had very fine equiaxed granular WC grains because of inhibited grain growth of WC. The Young’s modulus of the WC–20 mol% SiC–Cr3C2 ceramics decreased with increasing Cr3C2 content because Cr3C2 has a much lower Young’s modulus than WC. Cr3C2 addition below 0.9 mol% increased the Vickers hardness from 20.9 to 23.0 GPa, but a larger added amount reduced the Vickers hardness. The hardness of the WC–20 mol% SiC–Cr3C2 ceramics and the WC grain size obeyed a Hall–Petch-like relationship, suggesting that the hardness was strongly controlled by the WC grain size. A higher fracture toughness, 6.4 MPa m1/2, was obtained for the ceramics containing a small amount of Cr3C2 than for the binder-free WC. The addition of 0.1–0.3 mol% Cr3C2 improved the fracture toughness without reducing the hardness.

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