Spinel nitrides transparent ceramics

Kaplan, Sevki Samet; Kurama, Semra; Günkaya, Göktuğ

doi:10.1016/j.jeurceramsoc.2015.03.033

Cited by 5 publications

(5 citation statements)

References 37 publications

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“…On the other hand, the current passing through the ceramic bulk ( I bulk ) is proportional to particle volume (6 d 3 ). These current ratio is inversely proportional to the radius curvature of the particle (6/ d ) 22,23

\frac{I_{surf}}{I_{bulk}} ≃ \frac{π d^{2}}{π / 6 d^{3}} ≃ \frac{6}{d}

Hence, as a result of reducing the particle size, the current surface considerably increases, which causes SPS temperature reduction.…”

Section: Resultsmentioning

confidence: 99%

“…These current ratio is inversely proportional to the radius curvature of the particle (6/d). 22,23 Hence, as a result of reducing the particle size, the current surface considerably increases, which causes SPS temperature reduction. The above explanation on the relationship between SPS temperature and particle size indicates the importance of the effective ball-milling process for powder preparation before sintering.…”

Section: Evaluation Of the Prepared Alon Powder For Spsmentioning

confidence: 99%

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Highly transparent AlON fabricated via SPS synthesized by Al₂O₃/C core–shell starting powder and CRN method

Kamali

Mohebi

Taherian

et al. 2021

Int J Applied Ceramic Tech

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Gamma aluminum oxynitride (γ-AlON) with a cubic spinel structure is a stable solid solution of Al 2 O 3 -AlN system, which has been attracted much attention in recent decades. 1,2 Transparency of AlON fully dense specimen is in the wavelength range of about 0.2-5 μm. 3 AlON is appropriate for phosphor-converted white LED, light-emitting devices, load-bearing orthopedic, and ceramic semiconductors because of its excellent optical properties besides high hardness and strength. AlON can be used instead of sapphire with a lower price, for applications that excellent mechanical and optical properties are needed. [4][5][6] Carbothermal reduction and nitridation (CRN) method is the most applied technique for AlON fabrication comparing to the other methods. The first report of using the CRN method was published by Yamaguchi et al. in 1959. 6,7 This method needs simple equipment, cheaper raw materials compared to the solid phase reaction, and the final product of this technique has a uniform chemical composition in terms of stoichiometry. 6,8 Remained carbon content in the final product and various effective factors, which can hardly be controlled, are disadvantages of this method. When the CRN method uses as a single-step process, before producing enough amounts of AlN beside α-Al 2 O 3 , a large part of the AlO 2 gaseous species exists because of the high temperature (more than 1800°C) of synthesis. This results in an excessive reduction of Al 2 O 3 phase amount, and consequently, the AlN phase presents in the final product. 9,10 The main reaction of twostep CRN technique corresponds to reaction (1):This main reaction consists of two sub-reactions, which in the first step, γ-Al 2 O 3 reacts with carbon and nitrogen; accordingly, AlN is produced. In the second step, α-Al 2 O 3 reacts with AlN and AlON is fabricated as the final product. 6,11 (1) 64 + x 3 Al 2 O 3 + 3xC + xN 2 → 2Al 64+x 3 O 32−x N x + 3xCO

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\frac{I_{surf}}{I_{bulk}} ≃ \frac{π d^{2}}{π / 6 d^{3}} ≃ \frac{6}{d}

Hence, as a result of reducing the particle size, the current surface considerably increases, which causes SPS temperature reduction.…”

Section: Resultsmentioning

confidence: 99%

Section: Evaluation Of the Prepared Alon Powder For Spsmentioning

confidence: 99%

Highly transparent AlON fabricated via SPS synthesized by Al₂O₃/C core–shell starting powder and CRN method

Kamali

Mohebi

Taherian

et al. 2021

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

show abstract

“…Over the next several years, other researchers confirmed that a spinel-type phase named aluminum oxynitride (AlON) indeed exists in this system [11][12][13][14]. As a new ceramic material, AlON offers researchers additional options in oxide-non-oxide systems [15][16][17].…”

Section: Introductionmentioning

confidence: 93%

In situ reaction mechanism of MgAlON in Al–Al2O3–MgO composites at 1700°C under flowing N2

Tong

Yan

et al. 2017

Int J Miner Metall Mater

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Abstract:The Al-Al 2 O 3 -MgO composites with added aluminum contents of approximately 0wt%, 5wt%, and 10wt%, named as M 1 , M 2 , and M 3 , respectively, were prepared at 1700°C for 5 h under a flowing N 2 atmosphere using the reaction sintering method. After sintering, the Al-Al 2 O 3 -MgO composites were characterized and analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results show that specimen M 1 was composed of MgO and MgAl 2 O 4 . Compared with specimen M 1 , specimens M 2 and M 3 possessed MgAlON, and its production increased with increasing aluminum addition. Under an N 2 atmosphere, MgO, Al 2 O 3 , and Al in the matrix of specimens M 2 and M 3 reacted to form MgAlON and AlN-polytypoids, which combined the particles and the matrix together and imparted the Al-Al 2 O 3 -MgO composites with a dense structure. The mechanism of MgAlON synthesis is described as follows. Under an N 2 atmosphere, the partial pressure of oxygen is quite low; thus, when the Al-Al 2 O 3 -MgO composites were soaked at 580°C for an extended period, aluminum metal was transformed into AlN. With increasing temperature, Al 2 O 3 diffused into AlN crystal lattices and formed AlN-polytypoids; however, MgO reacted with Al 2 O 3 to form MgAl 2 O 4 . When the temperature was greater than (1640 ± 10)°C, AlN diffused into Al 2 O 3 and formed spinel-structured AlON. In situ MgAlON was acquired through a solid-solution reaction between AlON and MgAl 2 O 4 at high temperatures because of their similar spinel structures.

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“…Other ceramic systems such as Al 2 O 3 [23], MgO [24], MgAl 2 O 4 [16], ZrO 2 [14], or even Lu 3 NbO 7 [25] and Gd 3 TaO 7 [26] with cubic defect-fluorite structures, have also been reported. Non-oxide compositions have also been demonstrated, including nitrides (AlN [27] and AlON [28]), fluorides (MgF 2 [29], CaF 2 [30], SrF 2 [31], and BaF 2 [32]), and chalcogenides, such as sulfides (ZnS [33]), selenides (ZnSe [34]), and tellurates (KNbTeO 6 [35]). More recently, transparent ceramics have been successfully fabricated from high-entropy oxide [36] and fluoride [37] compositions, which were previously unattainable using conventional single-crystal growth processes.…”

Section: Transparent Ceramicsmentioning

confidence: 99%

Crystallization of glass materials into transparent optical ceramics

Milisavljevic

Pitcher

et al. 2022

International Materials Reviews

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Latest advancements in transparent ceramics development have ensured a mainstream research interest in this family of materials. Crystallization of glass into transparent ceramics has emerged recently as an alternative but complementary trajectory for obtaining transparent ceramics, which circumvents some of the long-standing technical difficulties associated with traditional transparent ceramics processing. The full bulk glass crystallization allows for the synthesis of high-density/low-porosity transparent ceramics of stable and metastable phases or even non-cubic structures, which are difficult to obtain using the traditional processing methods. This article presents a brief survey of the science of the transparency of ceramics and a detailed overview of the materials systems and techniques used for the preparation of transparent ceramics through the glass crystallization route. Finally, the review provides authors' insights into the future trends and research directions aimed to encourage a widespread application of glass crystallization into transparent ceramics in the fabrication of next-generation materials.

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Spinel nitrides transparent ceramics

Cited by 5 publications

References 37 publications

Highly transparent AlON fabricated via SPS synthesized by Al₂O₃/C core–shell starting powder and CRN method

Highly transparent AlON fabricated via SPS synthesized by Al₂O₃/C core–shell starting powder and CRN method

In situ reaction mechanism of MgAlON in Al–Al2O3–MgO composites at 1700°C under flowing N2

Crystallization of glass materials into transparent optical ceramics

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Spinel nitrides transparent ceramics

Cited by 5 publications

References 37 publications

Highly transparent AlON fabricated via SPS synthesized by Al2O3/C core–shell starting powder and CRN method

Highly transparent AlON fabricated via SPS synthesized by Al2O3/C core–shell starting powder and CRN method

In situ reaction mechanism of MgAlON in Al–Al2O3–MgO composites at 1700°C under flowing N2

Crystallization of glass materials into transparent optical ceramics

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Highly transparent AlON fabricated via SPS synthesized by Al₂O₃/C core–shell starting powder and CRN method

Highly transparent AlON fabricated via SPS synthesized by Al₂O₃/C core–shell starting powder and CRN method