Yield strength of α-silicon nitride at high pressure and high temperature

J. Qian, C. Pantea, J. Zhang, L. L. Daemen, Y. Zhao, M. Tang, T. Uchida, Y. Wang

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Through the analysis of peak broadening of energy-dispersive diffraction lines from a powdered sample, the yield strength of α-Si 3N 4 was investigated at a pressure of 9 G Pa and temperatures up to 1234°C. During compression at room temperature, the lattice strain deduced from peak broadening increased linearly with pressure up to 9.2 GPa, with no clear indication of strain saturation. While heating at 9 GPa, diffraction peaks narrowed and significant stress relaxation was observed at temperatures above 400°C, indicating the onset of yielding. The yield strength of α-Si 3N 4 decreases rapidly with increasing temperature: from 8.7 GPa at 400°C to 4.0 GPa at 1234°C. The low temperature for the onset of yielding and decrease of yield strength upon further heating bring up concern regarding the performance of α-Si 3N 4 as an engineering material. Finally, the grain size variation is also outlined together with the dependence of differential strain on pressure and on temperature. This provides crucial information for clarifying the "fine structure" of the evolution of the differential strain.

Original languageEnglish
Pages (from-to)903-906
Number of pages4
JournalJournal of the American Ceramic Society
Volume88
Issue number4
DOIs
StatePublished - Apr 2005
Externally publishedYes

Fingerprint

Dive into the research topics of 'Yield strength of α-silicon nitride at high pressure and high temperature'. Together they form a unique fingerprint.

Cite this