Gas/solid reaction during sintering of Si3N4 ceramics in an air furnace

Wangmooklang, Nirut; Sujirote, Kuljira; Jinawath, Supatra; Wada, Satoshi

doi:10.1016/j.jeurceramsoc.2006.06.004

Cited by 8 publications

(3 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in case of sintering of the porous Si 2 N 2 O ceramics in the powder bed A, decomposition of the Si 2 N 2 O in the inner parts of the samples would be a dependence on permeability ( K ) of the gaseous SiO. And mass transportation through the pore channels in the porous ceramic created a gradient of the SiO pressure across section of the ceramic (Figure ) …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si₂N₂O ceramics

et al. 2017

View full text Add to dashboard Cite

Porous silicon oxynitride (Si2N2O) ceramics were prepared by gas pressure sintering at 1650°C for 2 hour under 1.5 MPa N2 in two different powder beds, that is, h‐BN/Si3N4 or h‐BN/(Si3N4 + SiO2). Effects of the gaseous atmosphere in the powder bed and the pore diameter in the ceramics on formation of the Si2N2O phase and the oxidation resistance of the sintered porous ceramics were investigated. Results showed that presence of the gaseous SiO in the powder bed played a crucial role in suppressing decomposition of the Si2N2O phase at the outer surface of the material. Permeability of the gaseous substances was decreased when the pore diameter was small, to affect the phase composition and the oxidation behavior of the porous Si2N2O ceramics. The oxidation weight gain curves of the porous Si2N2O ceramics fitted the asymptotic law. No significant changes in the dielectric constant of the Si2N2O ceramics were observed after oxidation at 1000°C‐1200°C for up to 30 minutes, whereas the dielectric loss tangent was reduced by oxidation due to formation of SiO2. The as‐obtained porous Si2N2O ceramics could withstand a highest thermal shock of 1200°C when the outer surface could be sealed by the oxidation‐derived SiO2 layer.

show abstract

Section: Resultsmentioning

confidence: 99%

“…And mass transportation through the pore channels in the porous ceramic created a gradient of the SiO pressure across section of the ceramic (Figure 2). 21 The gas permeability (K) and the pressure gradient of the SiO in the porous ceramics could be described by Equation 4. 22…”

Section: Characterizationmentioning

confidence: 99%

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si₂N₂O ceramics

et al. 2017

View full text Add to dashboard Cite

show abstract

“…It should be noted that partial internal oxidation of the protective powder bed is expected during sintering, leading to the formation of SiO 2 in the powder bed (likely in higher concentrations than the samples themselves), which may aid in suppressing decomposition following , as outlined by Lange 25 . Wada and colleagues have also examined the sintering behavior of Si 3 N 4 ‐based ceramics in air, consistently noting that weight losses occur 12,13,27 . They proposed that above dominates, resulting in weight loss.…”

Section: Resultsmentioning

confidence: 99%

Sintering Behavior and Microstructure Development of Porous Silicon Nitride Ceramics Prepared in an Air Atmosphere Furnace

Plucknett¹

2009

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

Porous silicon nitride (Si 3 N 4 ) ceramics have been sintered in a conventional air atmosphere furnace at temperatures between 15001C and 17001C, with sintering additions of either 5 or 10 wt% yttria (Y 2 O 3 ). The use of a protective a-Si 3 N 4 powder bed helps to prevent significant oxidation of the samples during sintering in air, keeping oxidation weight gains below 4 wt% (typically o2.5 wt%). This compares with more typical weight losses when sintering in nitrogen. Samples prepared with a protective a-Si 3 N 4 powder bed exhibited sintered densities up to B89% of the theoretical, which was notably higher than for similar compositions prepared in a controlled nitrogen atmosphere (i.e., B70% of theoretical). Increased densification is proposed to arise from the formation of a thin SiO 2 surface layer on individual a-Si 3 N 4 particles, through passive oxidation, which is expected to promote viscous-flow densification at lower temperatures. The excess of SiO 2 , relative to the starting composition, is also reflected in the final phase assembly, with Si 2 N 2 O formed in addition to the transformation of ato b-Si 3 N 4 , when sintering above B15501C. A Si 2 N 2 O gradient occurs, with the surface being approximately 80 vol% Si 2 N 2 O and the bulk predominantly Si 3 N 4 , for samples sintered at 16001C and 17001C. Conversely, Si 2 N 2 O is not observed in any measurable volume for similar samples sintered in nitrogen.

show abstract

Protective Engobes for Si3N4 Ceramics Sintered in Air-Atmosphere Furnace

Tsanova

Djambazov

Dimitriev

2014

Interceram. - Int. Ceram. Rev.

View full text Add to dashboard Cite

Gas/solid reaction during sintering of Si3N4 ceramics in an air furnace

Cited by 8 publications

References 30 publications

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si₂N₂O ceramics

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si₂N₂O ceramics

Sintering Behavior and Microstructure Development of Porous Silicon Nitride Ceramics Prepared in an Air Atmosphere Furnace

Protective Engobes for Si3N4 Ceramics Sintered in Air-Atmosphere Furnace

Contact Info

Product

Resources

About

Gas/solid reaction during sintering of Si3N4 ceramics in an air furnace

Cited by 8 publications

References 30 publications

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si2N2O ceramics

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si2N2O ceramics

Sintering Behavior and Microstructure Development of Porous Silicon Nitride Ceramics Prepared in an Air Atmosphere Furnace

Protective Engobes for Si3N4 Ceramics Sintered in Air-Atmosphere Furnace

Contact Info

Product

Resources

About

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si₂N₂O ceramics

Effects of pore diameters on phase, oxidation resistance, and thermal shock resistance of the porous Si₂N₂O ceramics