Effect of Fe2O3 on the densification behaviour and mechanical properties of zirconia-toughened alumina (ZTA) composites prepared by two-stage sintering

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1030.3 ◽

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.

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Two-Stage Sintering of Nb2O5 Doped Zirconia Toughened Alumina (ZTA) Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.861.327 ◽

2020 ◽

Vol 861 ◽

pp. 327-333

Author(s):

Teow Hsien Loong ◽

Se Yong Eh Noum ◽

Wong Wai Mun

Keyword(s):

Mechanical Properties ◽

Hip Replacement ◽

Niobium Oxide ◽

Sintering Temperature ◽

Well Being ◽

Two Stage ◽

Total Hip ◽

Fine Grained ◽

Second Stage ◽

Zirconia Toughened Alumina

It is estimated that 130 million people will suffer from osteoarthritis by 2050 which require patient to undergo a surgical procedure known as total hip replacement which has lifespan of 20 years and failure rates of ~1%. This research would highlight the effects of doping Niobium Oxide (Nb2O5) between 0 vol % to 0.8 vol % into Zirconia-Toughened Alumina (ZTA) composites which is the main biomaterials used to manufacture total hip arthroplasty. The samples were sintered using two-stage sintering (TSS) between 1400°C and 1550°C for first-stage sintering temperature at heating rate of 20°C/min. At second stage, the samples were sintered at 1350°C and hold for 12 hours. It was found that TSS combined with addition of Nb2O5 as dopants were beneficial in producing fine-grained ZTA composites with improved mechanical properties compared to undoped ZTA composites produced via TSS. Compared to undoped ZTA composites, samples doped with Nb2O5 and sintered at T1 ≥1400°C were fully densed (>98%), achieved Vickers hardness more than 20 GPa and Young’s modulus higher than 410 GPa and at the same time fracture toughness of more than 8 MPam1/2. Based on the findings, production of ZTA composites with enhanced mechanical properties with longer lifespan is possible which is beneficial in ensuring the well-being of osteoarthritis patients.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1030.11 ◽

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.

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

MATEC Web of Conferences ◽

10.1051/matecconf/202133503019 ◽

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℃.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.904.174 ◽

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.

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Mechanical Properties of Zirconia Toughened Alumina Composites with TZP Partially Nanostructured Sintered by Liquid Fase

Materials Science Forum ◽

10.4028/www.scientific.net/msf.591-593.436 ◽

2008 ◽

Vol 591-593 ◽

pp. 436-440

Author(s):

João Marcos K. Assis ◽

Francisco Piorino Neto ◽

Francisco Cristóvão Lourenço de Melo ◽

Maria do Carmo de Andrade Nono

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Weibull Modulus ◽

Bending Test ◽

Sintering Aid ◽

Zirconia Composites ◽

Alumina Composites ◽

Grain Size And Shape ◽

Zirconia Toughened Alumina ◽

Zirconia Powders

A comparative study between alumina added niobia ceramics and two alumina zirconia composites from nanostructured TZP (7% and 14% weight) was made. On this composites the zirconia were yttria stabilized and the alumina were submicron structured. As sintering aid a mixture of magnesia, niobia and talc were used on all samples. The sintering was performed at 1450 oC during 60 minutes. The characteristic grain size and shape of an alumina and zirconia powders, aggregates and agglomerates were characterized. The sintering ceramics were evaluated through hardness, fracture toughness and 4 point bending test. Weibull statistic was applied on the flexural results. Although the fracture toughness result from ZTA were lower, and seems to be affected by the liquid fase, the hardness and Weibull modulus were higher than alumina niobia. The grains size and the homogeneity of its distributions on the microstructure of this ceramics was correlated to these higher values. The results from these alumina zirconia composites showed a potential to apply as a ballistic armor material.

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