Phase composition and fracture toughness of Si3N4–ZrO2 with CeO2 additions

Sigulinski, F.; Bošković, S.

doi:10.1016/s0272-8842(97)90082-1

Cited by 14 publications

(6 citation statements)

References 11 publications

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“…According to analogy with the previous system the amount of Si 2 ON 2 decreases with increasing temperature above 1600°C, while the amount of β-Si 3 N 4 rapidly growths [11]. The reason for this is the reaction of Si 2 N 2 O with Ce 2 O 3 and SiO 2 forming Ce/N/ apatite [17]. At 1700° and 1800° C, the presence of 3 N 4 and Ce 5 (SiO 4 ) 3 N is observed.…”

Section: Resultssupporting

confidence: 53%

Influence of Additive Type on Densification and Phase Transformation of Seeded Si3N4

Vučković¹,

Matović²,

Bošković³

2005

MSF

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This paper deals with densification and a®b phase transformation of Si3N4, with a constant b-Si3N4 seeds concentration regarding sintering temperature and different additive types. The seeds of b-Si3N4 were obtained by sintering of silicon nitride in a-form and additive mixture consisting of Y2O3 and SiO2. Two different Si3N4/additive mixtures (Y2O3 + Al2O3 and CeO2) containing constant amount of seeds were prepared and tested. Characterization of sintered samples involved phase analysis by X−ray diffraction and density measurements. The results indicated that in the presence of yttria-alumina mixture both the phase transformation and the densification were enhanced as compared to samples containing only CeO2 as a sintering additive. The reasons for observed behavior are discussed in detail.

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Section: Resultssupporting

confidence: 53%

Influence of Additive Type on Densification and Phase Transformation of Seeded Si3N4

Vučković¹,

Matović²,

Bošković³

2005

MSF

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“…Further studies showed 5 Author to whom any correspondence should be addressed. that some stabilizing oxides like CeO 2 in ZrO 2 -Me x O y solid solutions were more effective in toughening of Si 3 N 4 ceramics [4] but the mechanism is not clear. Therefore, the mechanical properties of β-SiAlON-ZrO 2 ceramic become a key issue for the application fields.…”

Section: Introductionmentioning

confidence: 99%

Analysis of load-penetration depth data using Oliver–Pharr and Cheng–Cheng methods of SiAlON–ZrO₂ceramics

Şahin¹,

Uzun²,

Sopicka-Lizer³

et al. 2008

J. Phys. D: Appl. Phys.

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Depth sensing indentation tests were carried out to obtain load–penetration depth curves of SiAlON–ZrO2 ceramics under different peak loads ranging from 200 to 1800 mN. The values of indentation hardness (HOP, HCC) and reduced elastic modulus (EOP, ECC) were calculated by using Oliver–Pharr (OP) and Cheng–Cheng (CC) methods. The experimental results revealed that the indentation hardness and reduced elastic modulus exhibit peak-load dependence, i.e. indentation size effect. Both indentation hardness and reduced elastic modulus values were obtained by considering indenter tip roundness and machine compliance. These values obtained from the OP method are higher than from the CC method. On the other hand, hf/hm ratios were used to clarify the indentation deformation behaviour of the SiAlON–ZrO2 ceramic. The experimental hf/hm values were lower than the reported critical value (0.7) for all applied test loads, which is attributed to work-hardening behaviour of SiAlON–ZrO2 composites.

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“…The Young's modulus values were between 298 and 264 GPa (Table 3), slightly lower than the typical value for silicon nitride of 300 GPa 34 . The Young's modulus is closely related to the final density and Vickers hardness of silicon nitride.…”

Section: Resultsmentioning

confidence: 59%

Influence of additive system (Al2O3-RE2O3 , RE = Y, La, Nd, Dy, Yb) on microstructure and mechanical properties of silicon nitride-based ceramics

Marchi

Silva²,

Silva

et al. 2009

Mat. Res.

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Silicon nitride based ceramics have been widely used as structural ceramics, due mainly to their thermomechanical properties such as high density, high thermal shock resistance, corrosion resistance and chemical stability. The aim of this study was to determine the influence of rare earth and aluminum oxide additions as sintering aids on densification, microstructure and mechanical properties of silicon nitride. Silicon nitride mixtures with 91 wt. (%) Si 3 N 4 and 9% wt. (%) additives were prepared and sintered. The density, microstructure and mechanical properties of the sintered specimens of these mixtures were determined. In most specimens, scanning electron microscopic examination and X ray diffraction analysis revealed elongated grains of β-Si 3 N 4 with aspect ratio of about 2.0 and dispersed in a glassy phase. The density of the sintered specimens was higher than 94% of the theoretical density (td) and specimens with La 2 O 3 and Al 2 O 3 additions exhibited the highest value. The results of this investigation indicate that the rare earth ion size influences densification of silicon nitride, but this correlation was not observed in specimens containing two different rare earth oxides. The hardness values varied in direct proportion to the density of the specimens and the fracture toughness values were influenced by the composition of the intergranular glassy phase.

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Phase composition and fracture toughness of Si3N4–ZrO2 with CeO2 additions

Cited by 14 publications

References 11 publications

Influence of Additive Type on Densification and Phase Transformation of Seeded Si<sub>3</sub>N<sub>4</sub>

Influence of Additive Type on Densification and Phase Transformation of Seeded Si<sub>3</sub>N<sub>4</sub>

Analysis of load-penetration depth data using Oliver–Pharr and Cheng–Cheng methods of SiAlON–ZrO₂ceramics

Influence of additive system (Al2O3-RE2O3 , RE = Y, La, Nd, Dy, Yb) on microstructure and mechanical properties of silicon nitride-based ceramics

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Phase composition and fracture toughness of Si3N4–ZrO2 with CeO2 additions

Cited by 14 publications

References 11 publications

Influence of Additive Type on Densification and Phase Transformation of Seeded Si<sub>3</sub>N<sub>4</sub>

Influence of Additive Type on Densification and Phase Transformation of Seeded Si<sub>3</sub>N<sub>4</sub>

Analysis of load-penetration depth data using Oliver–Pharr and Cheng–Cheng methods of SiAlON–ZrO2ceramics

Influence of additive system (Al2O3-RE2O3 , RE = Y, La, Nd, Dy, Yb) on microstructure and mechanical properties of silicon nitride-based ceramics

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Analysis of load-penetration depth data using Oliver–Pharr and Cheng–Cheng methods of SiAlON–ZrO₂ceramics