Mechanical and environmental factors in the cyclic and static fatigue of silicon nitride

Journal Article · Sun May 01 04:00:00 EDT 1994 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1994.tb05387.x· OSTI ID:7303153

Jacobs, D S; Chen, I W ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

The effects of environment on cyclic and static fatigue behavior were investigated with hot-pressed silicon nitride materials. Tests were conducted at ambient temperature on standard compact tension specimens, and a dc electric potential technique was used to monitor crack lengths in situ. The results indicate that the environmental sensitivity of the materials under both cyclic and static loading mirrors that of durable glasses in static fatigue. The materials were most sensitive to water in the environment, while changes in pH had no significant effect in the range tested. In addition, NH[sub 3] was much less reactive with the material than with vitreous SiO[sub 2]. In some cases, the intergranular glass appears to be the site of environmental interaction. Evidence was also found that cyclic fatigue is not simply a manifestation of static fatigue. Cyclic fatigue was seen to occur in the absence of measurable static fatigue, and the data indicate that the mechanism of cyclic fatigue involves damage to the crack wake shielding zone.

• OSTI ID: 7303153
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 77:5; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
AMMONIA
CHALCOGENIDES
CORROSION FATIGUE
CRACK PROPAGATION
DATA
EXPERIMENTAL DATA
FATIGUE
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
MECHANICAL PROPERTIES
NITRIDES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES
SILICON OXIDES
WATER