Tensile Creep and Rupture of Silicon Nitride

Published

May 1, 1999

Author(s)

Ralph Krause, William E. Luecke, J French, B Hockey, Sheldon M. Wiederhorn

Abstract

We have characterized the tensile creep, rupture lifetime, and cavitation behavior of a commercial, gas-pressure-sintered silicon nitride in the temperature range 1150 to 1400 C and stress range 70 to 400 MPa. Individual creep curves generally show primary, secondary, and tertiary creep. The majority of the primary creep is not recoverable. The best representation of the data is one where thecreep rate depends exponentially on stress, rather than on the traditional power law. This representation also removes the need to break the data into high and low stress regimes. Cavitation of the interstitial silicate phase accompaniescreep under all conditions, and accounts for nearly all of the measured strain. These observations are consistent with a model where creep proceeds by the redistribution of silicate phase from cavitating interstitial pockets, accommodated by grain-boundary sliding of silicon nitride.

Citation

Journal of the American Ceramic Society

Volume

82

Issue

No. 5

Pub Type

Journals

Keywords

ceramics, silicon nitride, tensile creep

Citation

Krause, R. , Luecke, W. , French, J. , Hockey, B. and Wiederhorn, S. (1999), Tensile Creep and Rupture of Silicon Nitride, Journal of the American Ceramic Society (Accessed September 10, 2024)