Methods and techniques for producing ceramics from aluminum oxynitride

Prosvirnin, D. V.; Колмаков, А. Г.; Larionov, M. D.; Prutskov, M. E.; Левина, А. В.

doi:10.1088/1757-899x/525/1/012067

Cited by 5 publications

(5 citation statements)

References 10 publications

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“…In the future, the interest will be on obtaining nano-sized grains with improved properties and performance [8,9]. The comprehensive overview of various manufacturing techniques was taken up in the recent years [14,15]. Earlier techniques for fabrication of AlON ceramics included reaction sintering [16][17][18], high temperature reactive synthesis, which is initiated by a combustion reaction between the precursors [19,20], and carbothermal synthesis [21][22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Processing of Al2O3-AlN Ceramics and Their Structural, Mechanical, and Tribological Characterization

et al. 2021

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The aim of this study is to present a novel, lower sintering temperature preparation, processing, structural, mechanical, and tribological testing of the AlN-Al2O3 ceramics. The precursor powder of AlN was subjected to oxidation in ambient environment at 900 °C for 3, 10, and 20 h, respectively. These oxidized powders were characterized by SEM and XRD to reveal their morphology, phase, and crystal structure. The SEM results showed coarse powder particles and the presence of aluminum oxide (Al2O3) phase at the surface of aluminum nitride (AlN). The XRD analysis has shown increasing aluminum-oxy-nitride conversion of aluminum nitride as the holding time of oxidation increased. The highest percentage of conversion of AlN powder to AlN-Al2O3 was observed after 10 h. Simultaneously the powders were compacted and sintered using the hot isostatic pressing (HIP) under inert environment (N2 gas) at 1700 °C, 20 MPa for 5 h. This led to the compaction and increase in density of the final samples. Mechanical tests, such as bending test and tribology tests, were carried out on the samples. The mechanical properties of the samples were observed to improve in the oxidized samples compared to the precursor AlN. Moreover, applying longer oxidation time, the mechanical properties of the sintered samples enhanced significantly. Optimum qualitative (microstructure, oxide percentage) and quantitative (tribology, hardness, and bending tests) properties were observed in samples with 10-h oxidation time.

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Section: Introductionmentioning

confidence: 99%

Processing of Al2O3-AlN Ceramics and Their Structural, Mechanical, and Tribological Characterization

et al. 2021

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“…As shown in Figure 11, Y 2 O 3 reacts with Al 2 O 3 to form a YAG liquid phase during the preparation of AlON ceramics. Owing to good wettability and fluidity, the liquid phase was uniformly dispersed in the gaps between the Al 2 O 3 and AlN particles under the action of capillary force, which promoted the rearrangement of particles and elimination of pores 17,42 . Moreover, the presence of the liquid phase significantly reduces the sintering activation energy of the sample owing to its low diffusion mass transfer resistance and high flow mass transfer rate, accounting for the slight decrease in the reaction temperature of Al 2 O 3 and AlN shown in Figure 9c 27 .…”

Section: Resultsmentioning

confidence: 99%

“…Owing to good wettability and fluidity, the liquid phase was uniformly dispersed in the gaps between the Al 2 O 3 and AlN particles under the action of capillary force, which promoted the rearrangement of particles and elimination of pores. 17,42 Moreover, the presence of the liquid phase significantly reduces the sintering activation energy of the sample owing to its low diffusion mass transfer resistance and high flow mass transfer rate, accounting for the slight decrease in the reaction temperature of Al 2 O 3 and AlN shown in Figure 9c. 27 Theoretically, the melting point of YAG is ∼1950 • C. 43 However, charge accumulation, inductive electromagnetic, and electric field concentration effects occur during the SPS of nonconductive powders, inducing the discharge phenomenon and local high-temperature state in the powders.…”

Section: 33mentioning

confidence: 99%

Effects of sintering aids on microstructure, mechanical, and optical properties of AlON ceramics synthesized by SPS

Jia

Zhang

et al. 2023

J Am Ceram Soc.

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Aluminum oxynitride (AlON) ceramics doped with different sintering aids were synthesized by spark plasma sintering process. The microstructures, mechanical, and optical properties of the ceramics were investigated. The results indicate that the optimal amount of sintering aids is 0.06 wt% La 2 O 3 + 0.16 wt% Y 2 O 3 + 0.30 wt% MgO. The addition of La 3+ and Mg 2+ decreases the rate of grain boundary migration in ceramics, promotes pore elimination, and inhibits grain growth. The addition of Y 3+ facilitates liquid-phase sintering of AlON ceramics. Moreover, the addition of Mg 2+ effectively promotes twin formation in the ceramics, which hinders crack propagation and dislocation motion when the ceramics are loaded. Hence, the AlON ceramic doped with 0.06 wt% La 2 O 3 + 0.16 wt% Y 2 O 3 + 0.30 wt% MgO exhibits a relative density of 99.95%, an average grain size of 9.42 μm, and a twin boundary content of 10.3%, which contributes to its excellent mechanical and optical properties.

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“…The HIP sintering of Al 2 O 3 ceramics has a long history of development, therefore is the most familiar for use in the processing of the many existing ceramics materials 14 . Prosvirnin et al communicated that in the production of oxynitride ceramics micro-additives of sintering components such as Y 2 O 3 , La 2 O 3 , and others are used 15 . The main sintering additive used in oxynitride ceramics is Y 2 O 3 , which has excellent physical and chemical properties, such as high melting point (2430° C) and the density is 5.01 g cm −3 15 .…”

Section: Introductionmentioning

confidence: 99%

“…Prosvirnin et al communicated that in the production of oxynitride ceramics micro-additives of sintering components such as Y 2 O 3 , La 2 O 3 , and others are used 15 . The main sintering additive used in oxynitride ceramics is Y 2 O 3 , which has excellent physical and chemical properties, such as high melting point (2430° C) and the density is 5.01 g cm −3 15 . Its presence can facilitate the liquid phase during sintering, which is beneficial for compacting and removing pores.…”

Section: Introductionmentioning

confidence: 99%

Effect of the pressureless post-sintering on the hot isostatic pressed Al2O3 prepared from the oxidized AlN powder

Balázsi

Varanasi

Horváth

et al. 2022

Sci Rep

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The effect of the pressureless post-sintering in hydrogen on the structural and mechanical properties of the hot isostatic pressed Al2O3 prepared by oxidized AlN powder has been studied. The micrometer size AlN powder has been oxidized in air at 900° C and sintered by hot isostatic pressing (HIP) at 1700 °C, 20 MPa nitrogen atmosphere for 5 h. Pressureless sintering (PS) has been applied for all HIP sintered samples in H2 gas at 1800° C for 10 h. It has been shown that the oxidation caused a core–shell AlN/Al2O3 structure and the amount of Al2O3 increased with increasing of the oxidation time of the AlN powder. For the first time, the green samples obtained from oxidized AlN powder have been successfully sintered first by HIP followed by post-sintering by PS under hydrogen without adding any sintering additives. All post-sintered samples exhibited the main α-Al2O3 phase. Sintering in H2 caused the full transformation of AlN to α-Al2O3 phase and their better densification. Therefore, the hardness values of post-sintered samples have been increased to 17–18 GPa having apparent densities between 3.11 and 3.39 g/cm3.

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Methods and techniques for producing ceramics from aluminum oxynitride

Cited by 5 publications

References 10 publications

Processing of Al2O3-AlN Ceramics and Their Structural, Mechanical, and Tribological Characterization

Processing of Al2O3-AlN Ceramics and Their Structural, Mechanical, and Tribological Characterization

Effects of sintering aids on microstructure, mechanical, and optical properties of AlON ceramics synthesized by SPS

Effect of the pressureless post-sintering on the hot isostatic pressed Al2O3 prepared from the oxidized AlN powder

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