Microstructural relationship with fracture toughness of undoped and rare earths (Y, La) doped Al2O3–ZrO2 ceramic composites

Maiti, Kuntal; Sil, Anjan

doi:10.1016/j.ceramint.2011.05.089

Cited by 39 publications

(26 citation statements)

References 32 publications

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“…The maximum Vickers hardness of Y3 (1867) was 29.8% higher than that of Y0 (1438) at 1650 °C. In agreement with many authors [30,[34][35][36][37], the improvement in Vickers hardness of the doped bodies is attributed to their better densification. The presence of pores in the ceramic body produce stress concentration points which develop cracks when the stress reaches a critical value.…”

Section: Vickers Hardnesssupporting

confidence: 88%

Physical and mechanical properties of Ta2O5 doped zirconia-toughened alumina (ZTA) composites

Naga

Hassan

Awaad

2015

Ceramics International

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Section: Vickers Hardnesssupporting

confidence: 88%

Physical and mechanical properties of Ta2O5 doped zirconia-toughened alumina (ZTA) composites

Naga

Hassan

Awaad

2015

Ceramics International

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“…Due to the large size of the Ln-ions compared to Al 3+ (0.054 nm for Al 3+ and 0.103 nm → 0.0861 nm for Ln 3+ series), which results in an ionic size mismatch between the dopants (Ln 3+ ) and the Al 3+ cations, the solubility of lanthanide cations in alumina is a significant challenge1314. Additionally, there is a limited understanding of the local structures and distributions of Ln-ions within the alumina matrix1516171819. Previous reports on Ln-doping of alumina have generally been conducted at doping concentrations of 0.5–5 wt%202122232425.…”

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confidence: 99%

Structural Effects of Lanthanide Dopants on Alumina

Patel

Blair

Douglas

et al. 2017

Sci Rep

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Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable. In this study, Ln-doping (400 ppm) of the alumina lattice crucially delays the onset of phase transformation and enables phase population control, which is achieved without the formation of new phases. The delay in phase transition (θ → α), and alteration of powder morphology, particle dimensions, and composition ratios between α- and θ-alumina phases are studied using a combination of solid state nuclear magnetic resonance, electron microscopy, digital scanning calorimetry, and high resolution X-ray diffraction with refinement fitting. Loading alumina with a sparse concentration of Ln-dopants suggests that the dopants reside in the vacant octahedral locations within the alumina lattice, where complete conversion into the thermodynamically stable α-domain is shown in dysprosium (Dy)- and lutetium (Lu)-doped alumina. This study opens up the potential to control the structure and phase composition of Ln-doped alumina for emerging applications.

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“…Zirconia toughened Al 2 O 3 (ZTA) has been reported to be one of the most successful commercial ceramic-based cutting inserts which fully utilize the advantages of zirconia [2]. Recently, materials with certain intermetallic matrices were reported to may also benefit from the addition of zirconia particles.…”

Section: Introductionmentioning

confidence: 99%

“…The properties of this ceramic are particularly attractive for structural applications such as in motor, aerospace, and biomedical fields, especially in severe environmental conditions [1]. Brittleness and poor damage tolerance have limited the scope of use as advanced engineering materials for almost all composition materials [2]. The fracture toughness of composition materials is generally low because the dislocation motion in the material is extremely limited due to the nature of the chemical bonds which are ionic and/or covalent.…”

Section: Introductionmentioning

confidence: 99%

The relationship between microstructure and fracture toughness of zirconia toughened alumina (ZTA) added with MgO and CeO2

Rejab

Azhar

Ratnam

et al. 2013

International Journal of Refractory Metals and Hard Materials

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The aim of this research is to investigate the mode of crack propagation in zirconia toughened alumina (ZTA) added with MgO and CeO 2 , respectively. The mode of crack refers to the toughening mechanism of the materials. Different ZTA compositions containing MgO and CeO 2 as sintering additives were prepared using pressureless sintering at 1600°C. Each sample was subjected to Vickers indentation with 294 N load and the cracks that propagated were observed with SEM. The ZTA with an addition of 0.7 wt.% MgO showed a crack deflection with a fracture toughness value of 6.19 ± 0.26 MPa · √m. On the other hand, the ZTA with CeO 2 addition of 0.5 to 7 wt.% showed both crack bridging and deflection, and produced 5.78 ± 0.16 MPa · √m to 6.59 ± 0.23 MPa · √m fracture toughness values, respectively. The fracture toughness of the ZTA-MgO-CeO 2 compositions is higher due to crack bridging and crack deflection. The toughening mechanisms of crack deflection and bridging hinder crack propagation since more energy is required to make the crack propagate. However, the formation of CeAl 11 O 18 phase was observed; this consequently decreases the hardness and fracture toughness of the ZTAMgO-CeO 2 compositions.

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Microstructural relationship with fracture toughness of undoped and rare earths (Y, La) doped Al2O3–ZrO2 ceramic composites

Cited by 39 publications

References 32 publications

Physical and mechanical properties of Ta2O5 doped zirconia-toughened alumina (ZTA) composites

Physical and mechanical properties of Ta2O5 doped zirconia-toughened alumina (ZTA) composites

Structural Effects of Lanthanide Dopants on Alumina

The relationship between microstructure and fracture toughness of zirconia toughened alumina (ZTA) added with MgO and CeO2

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