Comparison of fracture toughness testing methods applied to Si3N4 + Si3N4-whisker system

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(92)90197-M· OSTI ID:5571596

Dusza, J ^[1]

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1. Slovak Academy of Sciences, Institute of Experimental Metallurgy, Kosice, (Czechoslovakia)

The different methods of fracture toughness measurement in the Si3N4 + Si3N4-whisker system are compared. The Si3N4 + beat-Si3N4 whisker system with 20 wt pct of whiskers is studied. The system was prepared by hot pressing at 1800 C and 32 MPa. The developed indentation crack profile for the system under consideration is found to be of the Palmquist type in the whole range of the indentation load from 49 to 294 N. Fracture toughness values measured by single-edge notch beam (SENB), indentation strength, and MIS are in the interval from 6.5 Mpa sq rt m to 7.5 MPa sq rt m if, in the MIS method, the crack profile at the moment of catastrophic failure is taken into account. Higher fraction toughness values with the rising crack size achieved in bending tests on the samples with 'traction-cracks' suggest a rising R-curve behavior of the Si3N4 + 20 pct Si3N4 whisker system. 24 refs.

• OSTI ID: 5571596
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 26; ISSN SCRME; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
COMPARATIVE EVALUATIONS
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
CRYSTALS
EVALUATION
FRACTURE PROPERTIES
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MONOCRYSTALS
NITRIDES
NITROGEN COMPOUNDS
PHOTOGRAPHY
PHOTOMICROGRAPHY
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES
WHISKERS