Effects of graphite porosity and anisotropy on measurements of elastic modulus using laser untrasonics
Abstract
Laser ultrasonic techniques can be used to study the ultrasonic properties of nuclear graphites and can serve as tools in establishing relationships between materials microstructure and the macroscopic stiffnesses of graphite. Establishing structure-property relationships permits improved ultrasonic sensing of graphite microstructural changes related to service-induced degradation. Laser ultrasonic measurements were made using a pulsed Nd:YAG laser source and detection was performed using a Michelson-type interferometer. This source-receiver combination provides for non-contacting, highly linear transduction of broadbanded, ultrasonic pulses permitting simultaneous determination of longitudinal and shear stiffnesses. Measurements show that among the graphites examined, a change in density of 0.26 g/cm3 (average 1.8 g/cm3) results in a change in the longitudinal elastic stiffness of 9.2 GPa (average 11.3 GPa) and 3.2 GPa (average 4.3 GPa) for the shear stiffness. Larger variations in density were produced by controlled oxidation of IG-110 and NBG-18. Shear wave birefringence measurements using laser line sources in IG-110 and PCEA indicate that IG-110 behaves isotropically while PCEA displays texture characteristic of transversely isotropic materials.
- Authors:
-
- Johns Hopkins University
- ORNL
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- Work for Others (WFO)
- OSTI Identifier:
- 1154857
- DOE Contract Number:
- DE-AC05-00OR22725
- Resource Type:
- Conference
- Resource Relation:
- Conference: 2014 IEEE International Ultrasonics Symposium, Chicago, IL, USA, 20140903, 20140905
- Country of Publication:
- United States
- Language:
- English
- Subject:
- GRAPHITE; POROSITY; ANISOTROPY; laser ultrasonics; graphite; porosity; Young s modulus; anisotropy; shear birefringence
Citation Formats
Spicer, James B, Zeng, Fan W, Han, Karen, Olasov, Lauren R, Gallego, Nidia C, and Contescu, Cristian I. Effects of graphite porosity and anisotropy on measurements of elastic modulus using laser untrasonics. United States: N. p., 2014.
Web.
Spicer, James B, Zeng, Fan W, Han, Karen, Olasov, Lauren R, Gallego, Nidia C, & Contescu, Cristian I. Effects of graphite porosity and anisotropy on measurements of elastic modulus using laser untrasonics. United States.
Spicer, James B, Zeng, Fan W, Han, Karen, Olasov, Lauren R, Gallego, Nidia C, and Contescu, Cristian I. 2014.
"Effects of graphite porosity and anisotropy on measurements of elastic modulus using laser untrasonics". United States.
@article{osti_1154857,
title = {Effects of graphite porosity and anisotropy on measurements of elastic modulus using laser untrasonics},
author = {Spicer, James B and Zeng, Fan W and Han, Karen and Olasov, Lauren R and Gallego, Nidia C and Contescu, Cristian I},
abstractNote = {Laser ultrasonic techniques can be used to study the ultrasonic properties of nuclear graphites and can serve as tools in establishing relationships between materials microstructure and the macroscopic stiffnesses of graphite. Establishing structure-property relationships permits improved ultrasonic sensing of graphite microstructural changes related to service-induced degradation. Laser ultrasonic measurements were made using a pulsed Nd:YAG laser source and detection was performed using a Michelson-type interferometer. This source-receiver combination provides for non-contacting, highly linear transduction of broadbanded, ultrasonic pulses permitting simultaneous determination of longitudinal and shear stiffnesses. Measurements show that among the graphites examined, a change in density of 0.26 g/cm3 (average 1.8 g/cm3) results in a change in the longitudinal elastic stiffness of 9.2 GPa (average 11.3 GPa) and 3.2 GPa (average 4.3 GPa) for the shear stiffness. Larger variations in density were produced by controlled oxidation of IG-110 and NBG-18. Shear wave birefringence measurements using laser line sources in IG-110 and PCEA indicate that IG-110 behaves isotropically while PCEA displays texture characteristic of transversely isotropic materials.},
doi = {},
url = {https://www.osti.gov/biblio/1154857},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 2014},
month = {Wed Jan 01 00:00:00 EST 2014}
}