Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Instrumented indentation and ultrasonic velocity techniques for the evaluation of creep cavitation in silicon nitride

Published

Author(s)

Gerald V. Blessing, Douglas T. Smith, Sheldon M. Wiederhorn, W E. Luecke

Abstract

Instrumented indentation and ultrasonic wave velocity techniques combined with precise density change measurements and transmission electron microscopy (TEM) were used to investigate the changes of elastic moduli in silicon nitride after tensile deformation up to 3%. Linear dependencies on strain were also found for the degradation of the indentation modulus, longitudinal and transverse ultrasonic wave velocities, Young''s, shear and bulk moduli and Poisson''s ratio. The results obtained by indentation technique and ultrasonic method were essentially identical. TEM observation confirmed that multigrain junction cavities were responsible for the density changes and the elastic moduli degradation. The density changes were linearly proportional to tensile strain with the slope of 0.75. Thus, cavitation is the dominant creep mechanism in silicon nitride studied.
Citation
Journal of Materials Science
Volume
38 (7)

Keywords

cavitation, creep damage, elastic moduli, indentation, silicon nitride, TEM, ultrasonic wave velocity

Citation

Blessing, G. , Smith, D. , Wiederhorn, S. and Luecke, W. (2003), Instrumented indentation and ultrasonic velocity techniques for the evaluation of creep cavitation in silicon nitride, Journal of Materials Science (Accessed April 25, 2024)
Created April 1, 2003, Updated February 19, 2017