Microstructure and fracture characteristics of Si{sub 3}N{sub 4}-ZrO{sub 2}(MgO) ceramic composite studied by transmission electron microscopy

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Scripta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-716X(95)00077-9· OSTI ID:39885

Lee, B T; Koyama, Takashi; Hiraga, Kenji ^[1]; Nishiyama, Akio ^[2]

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1. Tohoku Univ., Sendai (Japan).Inst. for Materials Research
2. Mitsubishi Material Co., Omiya (Japan). Central Research Inst.

ZrO{sub 2}, which is well known as a phase transformation toughening ceramic, has been widely used as a toughening agent in Si{sub 3}N{sub 4} and Al{sub 2}O{sub 3} matrix composites to improve their mechanical properties. In the Si{sub 3}N{sub 4}-ZrO{sub 2} composites, unstabilized or Y{sub 2}O{sub 3} partially stabilized ZrO{sub 2} is usually used as raw powders, and values of fracture strength and toughness increase with increasing the volume fraction of ZrO{sub 2} up to about 30%, whereas hardness decreases. Therefore, an optimum content of ZrO{sub 2} is desirable for the application of a wear part. Also, ZrO{sub 2} is expected to play the role of a sintering additive. There were many reports on fabrication and mechanical properties for the Si{sub 3}N{sub 4}-ZrO{sub 2} composites, but the relationship between microstructures and a fracture characteristic has little reported until now. In this study, the authors present the results of microstructures and fracture characteristics studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and a micro-indentation fracture technique for a Si{sub 3}N{sub 4}-5wt.%ZrO{sub 2}(5wt.%MgO) composite.

• OSTI ID: 39885
• Journal Information: Scripta Metallurgica et Materialia, Journal Name: Scripta Metallurgica et Materialia Journal Issue: 7 Vol. 32; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
FRACTURE PROPERTIES
HOT PRESSING
MAGNESIUM OXIDES
MICROSTRUCTURE
MORPHOLOGY
SAMPLE PREPARATION
SCANNING ELECTRON MICROSCOPY
SILICON NITRIDES
X-RAY DIFFRACTION
ZIRCONIUM OXIDES