The Effect of Microstructure on Fracture Toughness for Silicon Nitride Ceramics

J. Yang; T. Sekino; K. Niihara

The Effect of Microstructure on Fracture Toughness for Silicon Nitride Ceramics

J. Yang, T. Sekino, K. Niihara

Research output: Contribution to journal › Article › peer-review

Abstract

Effect of microstructure on the fracture toughness for Si₃N₄ ceramics were studied. The Si₃N₄ ceramics were fabricated by pressureless sintering using two kinds of Si₃N₄ powders (high purity powder: E10, and relatively low purity powder: 9S) as starting powders. Grain growth of β-silicon nitride was controlled by keeping time and sintering temperature. The fracture toughness was measured by indentation fracture (IF) method and single-edge-precracked-beam (SEPB) method. There was a discrepancy between the fracture toughness values obtained by these two methods. From this study it was found that the materials with more large elongated Si₃N₄ grains gave higher fracture toughness, R-curve behavior and large discrepancy. This was contributed to the effects of grain bridging, pull-out and deflection by large elongated Si₃N₄ grains. Comparing the specimens fabricated from the E10 and 9S powders, both reached high fracture toughness over 9 MPa·m^1/2 by the SEPB method.

Original language	English
Pages (from-to)	195-198
Number of pages	4
Journal	Key Engineering Materials
Volume	161-163
Publication status	Published - 1999 Jan 1
Externally published	Yes

Keywords

Fracture Toughness
Grain Growth
Silicon Nitride

ASJC Scopus subject areas

Materials Science(all)
Mechanics of Materials
Mechanical Engineering

Cite this

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title = "The Effect of Microstructure on Fracture Toughness for Silicon Nitride Ceramics",

abstract = "Effect of microstructure on the fracture toughness for Si3N4 ceramics were studied. The Si3N4 ceramics were fabricated by pressureless sintering using two kinds of Si3N4 powders (high purity powder: E10, and relatively low purity powder: 9S) as starting powders. Grain growth of β-silicon nitride was controlled by keeping time and sintering temperature. The fracture toughness was measured by indentation fracture (IF) method and single-edge-precracked-beam (SEPB) method. There was a discrepancy between the fracture toughness values obtained by these two methods. From this study it was found that the materials with more large elongated Si3N4 grains gave higher fracture toughness, R-curve behavior and large discrepancy. This was contributed to the effects of grain bridging, pull-out and deflection by large elongated Si3N4 grains. Comparing the specimens fabricated from the E10 and 9S powders, both reached high fracture toughness over 9 MPa·m1/2 by the SEPB method.",

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author = "J. Yang and T. Sekino and K. Niihara",

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T1 - The Effect of Microstructure on Fracture Toughness for Silicon Nitride Ceramics

AU - Yang, J.

AU - Sekino, T.

AU - Niihara, K.

PY - 1999/1/1

Y1 - 1999/1/1

N2 - Effect of microstructure on the fracture toughness for Si3N4 ceramics were studied. The Si3N4 ceramics were fabricated by pressureless sintering using two kinds of Si3N4 powders (high purity powder: E10, and relatively low purity powder: 9S) as starting powders. Grain growth of β-silicon nitride was controlled by keeping time and sintering temperature. The fracture toughness was measured by indentation fracture (IF) method and single-edge-precracked-beam (SEPB) method. There was a discrepancy between the fracture toughness values obtained by these two methods. From this study it was found that the materials with more large elongated Si3N4 grains gave higher fracture toughness, R-curve behavior and large discrepancy. This was contributed to the effects of grain bridging, pull-out and deflection by large elongated Si3N4 grains. Comparing the specimens fabricated from the E10 and 9S powders, both reached high fracture toughness over 9 MPa·m1/2 by the SEPB method.

AB - Effect of microstructure on the fracture toughness for Si3N4 ceramics were studied. The Si3N4 ceramics were fabricated by pressureless sintering using two kinds of Si3N4 powders (high purity powder: E10, and relatively low purity powder: 9S) as starting powders. Grain growth of β-silicon nitride was controlled by keeping time and sintering temperature. The fracture toughness was measured by indentation fracture (IF) method and single-edge-precracked-beam (SEPB) method. There was a discrepancy between the fracture toughness values obtained by these two methods. From this study it was found that the materials with more large elongated Si3N4 grains gave higher fracture toughness, R-curve behavior and large discrepancy. This was contributed to the effects of grain bridging, pull-out and deflection by large elongated Si3N4 grains. Comparing the specimens fabricated from the E10 and 9S powders, both reached high fracture toughness over 9 MPa·m1/2 by the SEPB method.

KW - Fracture Toughness

KW - Grain Growth

KW - Silicon Nitride

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SN - 1013-9826

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The Effect of Microstructure on Fracture Toughness for Silicon Nitride Ceramics

Abstract

Keywords

ASJC Scopus subject areas

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