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.

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.

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℃.

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.

Effects of Ramp Rates with Short Holding Time on the Sinterability of Hydroxyapatite

2012 ◽  
Vol 545 ◽  
pp. 229-234
Author(s):  
Lai Kuan Lee Samuel ◽  
Chou Yong Tan ◽  
Ramesh Singh ◽  
Boon Kar Yap ◽  
Ranna Tolouei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Human Bone ◽  
Holding Time ◽  
Ramp Rate ◽  
The Poor ◽  
Bone Replacement ◽  
Sample Characterization

Hydroxyapatite (HA) is by far the closest match to the human bone in terms of chemical composition. Furthermore, HA boasts excellent biocompatibility thus earning its reputation for human bone replacement. However, HA lacks desirable mechanical properties (i.e. hardness, fracture toughness, etc.). Due to the poor heat conductivity of ceramics, it is hypothesized that HA when sintered via conventional pressureless sintering, smaller ramp rates are advantageous as oppose to larger ramp rates. These advantages can be observed as improved densification along with improved mechanical properties. In the present work, the sintering profile for the HA green bodies were held at 1 minute in comparison to the usual 2 hours holding time. The applied ramp rates were 2 °C/min, 5 °C/min and 10 °C/min. Sintering temperatures were set to 1000, 1100, 1200, and 1300 °C. Sample characterization was then reviewed in the aspects of phase stability, % shrinkage, bulk and relative density, Young’s modulus, Vickers hardness, as well as fracture toughness. The results revealed that sintering with shorter holding time yielded an improvement in the mechanical properties of HA. It was observed that sintering HA with a 2 °C/min ramp rate does not result in the formation of extrageneous phases even when sintered to 1300 °C. Similarly at 2 °C/min and 1300 °C, densification was observed to be 99.05 %. In addition, Young’s modulus recorded its highest value (117.03 GPa) when sintered with a ramp rate of 2°C/min. It was also observed that sintering HA at a ramp rate of 2°C/min produced a hardness value of 5.88 GPa (improvement of 0.68 GPa when compared with 2 hours holding time).

scholarly journals Effects of CNT Addition on Mechanical Properties, Electric Conductivity and Oxidation Resistance of Al2O3-TiC Composite

2013 ◽  
Vol 761 ◽  
pp. 83-86
Author(s):  
Hideaki Sano ◽  
Junichi Morisaki ◽  
Guo Bin Zheng ◽  
Yasuo Uchiyama
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Electric Conductivity ◽  
Young’S Modulus ◽  
Oxidation Resistance ◽  
Young's Modulus ◽  
Tic Particle

Effects of carbon nanotubes (CNT) addition on mechanical properties, electric conductivity and oxidation resistance of CNT/Al2O3-TiC composite were investigated. It was found that flexural strength, Young’s modulus and fracture toughness of the composites were improved by addition of more than 2 vol%-CNT. In the composites with more than 3 vol%-CNT, the oxidation resistance of the composite was degraded. In comparison with Al2O3-26vol%TiC sample as TiC particle-percolated sample, the Al2O3-12vol%TiC-3vol%CNT sample, which is not TiC particle-percolated sample, shows almost the same mechanical properties and electric conductivity, and also shows thinner oxidized region after oxidation at 1200°C due to less TiC in the composite.

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.

Effect of temperature on properties of aluminum/single-walled carbon nanotube nanocomposite by molecular dynamics simulation

2019 ◽  
Vol 234 (2) ◽  
pp. 635-642 ◽  
Author(s):  
Mohsen Motamedi ◽  
AH Naghdi ◽  
SK Jalali
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Metal Composite

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing temperature, the Young’s modulus of composite was decreased. More specifically increasing the temperature from 150 K to 620 K, decrease the Young’s modulus to 11.7%. The ultimate stress of composite also decreased by increasing the temperature. A continuum model of composite was presented using finite element method. The results showed the role of carbon nanotube on strengthening of composite.

The Effect of Ta2O5 on the Densification Behaviour and Mechanical Properties of Zirconia-Toughened Alumina (ZTA) Composites Prepared by Two-Stage Sintering

2020 ◽  
Vol 861 ◽  
pp. 320-326
Author(s):  
Teow Hsien Loong ◽  
Se Yong Eh Noum ◽  
Wong Wai Mun
Keyword(s):  
Mechanical Properties ◽  
Hip Replacement ◽  
Sintering Temperature ◽  
Tantalum Oxide ◽  
Well Being ◽  
Two Stage ◽  
Total Hip ◽  
Second Stage ◽  
Replacement Procedure ◽  
Zirconia Toughened Alumina

By 2050, 130 million people are estimated to suffer from osteoarthritis worldwide which would require patients to undergo total hip replacement procedure which have a lifespan of 20 years and failure rates of ~1%. In this research, Zirconia Toughened Alumina (ZTA) which is the main biomaterial used for total hip arthroplasty were doped with varying vol % of Tantalum Oxide (Ta2O5) from 0 to 0.4 vol % were produced through conventional two-stage sintering with first stage sintering temperature, ranging between 1400°C and 1550°C, heated at 20°C/min, followed by second stage sintering temperature of 1350°C and hold for 12 hours. The efficacy of two-stage sintering on the microstructure and mechanical properties of the sintered samples were then evaluated. Addition of Ta2O5 combined with two-stage sintering were able to produce ZTA composites with enhanced grain size and mechanical properties compared to undoped ZTA composites. The samples with 0.3 vol% Ta2O5 content and above sintered at T1 ≥1450°C achieved density > 99% T.D., Vickers hardness > 19 GPa, Young’s modulus > 400 GPa and fracture toughness > 6 MPam1/2 when compared to undoped ZTA composites. This would enable production of ZTA with improved mechanical properties and lifespan ensuring the well-being of people suffering from osteoarthritis.

Mechanical Properties of Transparent Polycrystalline Silicon Nitride

2006 ◽  
Vol 317-318 ◽  
pp. 305-308 ◽  
Author(s):  
Rak Joo Sung ◽  
Takafumi Kusunose ◽  
Tadachika Nakayama ◽  
Yoon Ho Kim ◽  
Tohru Sekino ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Nitride ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Polycrystalline Silicon ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Β Phase ◽  
Α Phase

A novel transparent polycrystalline silicon nitride was fabricated by hot-press sintering with MgO and AlN as additives. The mixed powder with 3 wt.% MgO and 9 wt.% AlN was sintered at 1900oC for 1 hour under 30 MPa pressure in a nitrogen gas atmosphere. Transparent polycrystalline silicon nitride was successfully fabricated. The mechanical properties such as density, hardness, young’s modulus, fracture strength and fracture toughness were evaluated. The effect of α/β phase on the mechanical properties of transparent polycrystalline silicon nitride was investigated. The properties were changed depending on the amount of α/β phase. The hardness and Young's modulus increased with increasing the volume fraction of α-phase fraction as a reflection of the higher hardness of α-phase Si3N4. The fracture toughness and fracture strength decreased with decreasing the volume fraction of β-phase Si3N4.

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