Fabrication of high thermal conductivity silicon nitride ceramics by pressureless sintering with MgO and Y2O3 as sintering additives

Lu, Tao; Wang, Tun; Jia, Yingfei; Ding, Maomao; Shi, Ying; Xie, Ju; Lei, Fang; Zhang, Lei; Fan, Lingcong

doi:10.1016/j.ceramint.2020.07.198

Cited by 24 publications

(8 citation statements)

References 20 publications

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“…As evident from Figure 5D–F, the interlocked structure formed by the rod‐shaped β‐Si 3 N 4 grains effectively enhances the fracture toughness of Si 3 N 4 ceramics 27,35,38,39 . The β‐Si 3 N 4 grains in Si 3 N 4 ceramics are rod‐shaped and unoriented arrangement.…”

Section: Resultsmentioning

confidence: 88%

“…As evident from Figure 5D-F, the interlocked structure formed by the rod-shaped β-Si 3 N 4 grains effectively enhances the fracture toughness of Si 3 N 4 ceramics. 27,35,38,39 The β-Si 3 N 4 grains in Si 3 N 4 ceramics are rod-shaped and unoriented arrangement. Therefore, when the orientation difference between adjacent grains is large, the crack is deflected in the process of propagation.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si ₃ N ₄ seeds and nanophase additives

Jiang

Zhuang

Wang

et al. 2022

Int J Applied Ceramic Tech

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Si 3 N 4 ceramics with high thermal conductivity and outstanding mechanical properties were prepared by adding β-Si 3 N 4 seeds and nanophase α-Si 3 N 4 powders as modifiers. The introduction of β-Si 3 N 4 seeds enhanced the growth of β-Si 3 N 4 grains. Owing to the interlocked structure induced by the β-Si 3 N 4 grains, the fracture toughness of Si 3 N 4 ceramics reached a high value of 7.6 MPa⋅m 1/2 ; also, the large-sized grains increased the contact possibility of Si 3 N 4 grains, improving the thermal conductivity of Si 3 N 4 ceramics (64 W/(m⋅K)). Because of the introduction of nanophase α-Si 3 N 4 , the flexural strength, fracture toughness, and thermal conductivity of the Si 3 N 4 ceramics increased to 754 MPa, 7.2 MPa⋅m 1/2 , and 54 W/(m⋅K), respectively. According to the analysis of the growth kinetics of Si 3 N 4 grains, the rapid growth of Si 3 N 4 grains was ascribed to the reduction in the activation energy resulting from the introduction of β-Si 3 N 4 seeds and nanophase α-Si 3 N 4 .

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Section: Resultsmentioning

confidence: 88%

Section: Mechanical Propertiesmentioning

confidence: 99%

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si ₃ N ₄ seeds and nanophase additives

Jiang

Zhuang

Wang

et al. 2022

Int J Applied Ceramic Tech

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show abstract

“…The majority of reports available on pressureless sintering of Si 3 N 4 have used high sintering temperatures (≥1800°C), long processing times, high additive content, packing powder, or post‐sintering treatment 10,13,18,22 . All these features are not favorable from the economic point of view.…”

Section: Introductionmentioning

confidence: 99%

“…20 Duan and coworkers obtained a flexural strength of 668 MPa using 10 wt.% TiO 2 -MgO-sintering aid and pressureless sintering at 1780 • C. 21 The majority of reports available on pressureless sintering of Si 3 N 4 have used high sintering temperatures (≥1800 • C), long processing times, high additive content, packing powder, or post-sintering treatment. 10,13,18,22 All these features are not favorable from the economic point of view. The subordinate value of any of the parameters (temperature, holding time, and additive content) results in unsatisfactory microstructure and properties.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of highly dense Si₃N₄ via record low‐content additive system for low‐temperature pressureless sintering

Kumar

Kim

et al. 2022

J Am Ceram Soc.

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Dense Si3N4 ceramics were fabricated by pressureless sintering at a low temperature of 1650°C with a short holding period of 1 h under a nitrogen atmosphere. The role of ternary oxide additives (Y2O3–MgO–Al2O3, Y2O3–MgO–SiO2, Y2O3–MgO–ZrO2) on the phase, microstructure, and mechanical properties of Si3N4 was examined. Only 5 wt.% of Y2O3–MgO–Al2O3 additive was sufficient to achieve >98% of theoretical density with remarkably high biaxial strength (∼1200 MPa) and prominent hardness (∼15.5 GPa). Among the three additives used, Y2O3–MgO–Al2O3 displayed the finest grain diameter (0.54 μm), whereas Y2O3–MgO–ZrO2 produced the largest average grain diameter (∼0.95 μm); the influence was seen on their mechanical properties. The low additive content Si3N4 system is expected to have superior high‐temperature properties compared to the system with high additive content. This study shows a cost‐effective fabrication of highly dense Si3N4 with excellent mechanical properties.

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“…Compared to open-cell structures, closed-cell structures have advantages in thermal insulation due to their load-bearing cell walls [10][11][12][13] and have received considerable attention in recent studies. For lms with high thermal insulation performance, in addition to the design of porous structure lms, low thermal conductivity of the material itself is important, such as for yttrium oxide (Y 2 O 3 ) materials [14,15].…”

Section: Introductionmentioning

confidence: 99%

Thermal Insulation Properties of Hollow Y2O3:Eu Spheres Laminated with Er2O3

Dan

Nakamura²,

Saitoh

et al. 2021

Preprint

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Currently, hollow sphere insulating materials are of importance for applications such as energy storage and savings and cryogenic engineering. The structures are formed by single hollow spheres, which can be joined, for example, by sintering. In this study, a 15 wt% Er-EDTA complex aqueous solution in which hollow Y2O3 spheres were mixed was used as the deposition body, and pencil spraying and sintering (PSS) was used to synthesize an Er2O3 hollow Y2O3 sphere composite film on a polished Si substrate. The structure of the composite film was successfully controlled by adjusting the 15 wt% Er-EDTA solution/hollow Y2O3 sphere mass ratio and the jet-to-substrate distance in the PSS process. In addition, the thermal insulation capability of the films was evaluated by the thermal steady-state method. The results show that the Er2O3/hollow Y2O3:Eu sphere composite films have a higher thermal insulation capability at a jet-to-substrate distance of 150 mm and a mass ratio (g) of 3.5:1. For the composite films with thicknesses of 38–92 µm, cross-sectional hollow ratio of 0.8–8.7% and void ratio of 6.3–13.1%, the temperature drop due to the porous (including hollow spheres and voids) structure films at 440°C is ΔTf =47°C. This is mainly associated with the film having more complicated microstructures. Therefore, the Er2O3/Y2O3:Eu composite film has good thermal insulation performance, and a simple preparation method for many kinds of hollow sphere films with complex structures and high porosities by using complex solutions with different compositions is provided.

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Fabrication of high thermal conductivity silicon nitride ceramics by pressureless sintering with MgO and Y2O3 as sintering additives

Cited by 24 publications

References 20 publications

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si ₃ N ₄ seeds and nanophase additives

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si ₃ N ₄ seeds and nanophase additives

Fabrication of highly dense Si₃N₄ via record low‐content additive system for low‐temperature pressureless sintering

Thermal Insulation Properties of Hollow Y2O3:Eu Spheres Laminated with Er2O3

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Fabrication of high thermal conductivity silicon nitride ceramics by pressureless sintering with MgO and Y2O3 as sintering additives

Cited by 24 publications

References 20 publications

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si 3 N 4 seeds and nanophase additives

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si 3 N 4 seeds and nanophase additives

Fabrication of highly dense Si3N4 via record low‐content additive system for low‐temperature pressureless sintering

Thermal Insulation Properties of Hollow Y2O3:Eu Spheres Laminated with Er2O3

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Product

Resources

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Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si ₃ N ₄ seeds and nanophase additives

Preparation, microstructure, and properties of GPS silicon nitride ceramics with β‐Si ₃ N ₄ seeds and nanophase additives

Fabrication of highly dense Si₃N₄ via record low‐content additive system for low‐temperature pressureless sintering