Fabrication of Silicon Nitride Ceramics with Pore Gradient Structure

Journal Article · Fri Feb 15 04:00:00 EST 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2896812· OSTI ID:21055251

Lianmeng, Zhang; Fei, Chen; Qiang, Shen; Faqiang, Yan ^[1]

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1. State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

In the present study, Si{sub 3}N{sub 4} ceramics with pore gradient structure were prepared by spark plasma sintering (SPS) technique. Silicon nitride ceramics with different controlled porosities were prepared by using ZrP{sub 2}O{sub 7} as a binder material and heat treated at 1100 deg. C in a pressureless nitrogen atmosphere. Si{sub 3}N{sub 4} ceramics with controlled porosity of 34-47% were obtained. The distribution of porous structure was homogenous. Fully dense Si{sub 3}N{sub 4} ceramics could be sintered at 1400{approx}1600 deg. C by using MgO and alumina Al{sub 2}O{sub 3} as the sintering aids. Pore gradient structure was formed by laminating the Si{sub 3}N{sub 4} porous ceramics and powder mixture was used to obtain fully dense ceramics, and then sintering at 1400-1600 deg. C. Microstructure of sintered samples was observed by scanning electronic microscope (SEM) and the change of phase compositions was analyzed by X-ray diffraction (XRD). The results showed that these samples exhibited a good porous graded structure with a highly porous layer and a dense surface layer. The major phase of the Si{sub 3}N{sub 4} ceramics was still {alpha} phase.

• OSTI ID: 21055251
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 973; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM OXIDES
CERAMICS
HEAT TREATMENTS
MAGNESIUM OXIDES
MICROSTRUCTURE
MIXTURES
POROSITY
POROUS MATERIALS
POWDERS
SCANNING ELECTRON MICROSCOPY
SILICON NITRIDES
SINTERING
X-RAY DIFFRACTION
ZIRCONIUM PHOSPHATES