Examination of the epicentral waveform for laser ultrasound in the melting regime

S. J. Reese; Z. N. Utegulov; F. Farzbod; R. S. Schley; D. H. Hurley

doi:10.1016/j.ultras.2012.11.007

Examination of the epicentral waveform for laser ultrasound in the melting regime

S. J. Reese, Z. N. Utegulov, F. Farzbod, R. S. Schley, D. H. Hurley

Research output: Contribution to journal › Article › peer-review

7 Scopus citations

Abstract

A laser ultrasonic source just below the ablation regime is examined by recording an epicentral waveform in a high purity tungsten sample. Using pulse energy as a parameter, a slight delay in the shear wave arrival time is observed upon transition to the melting regime. This phenomenon is attributed to a change in character of the ultrasonic source. In the thermoelastic regime, shear waves are generated by mode conversion at the sample surface of longitudinal waves emanating from subsurface sources. Just above the melting threshold, a molten pool forms in the center of the generation volume. Shear waves are not supported by the molten pool. As a result, shear waves generated from off-axis thermoelastic sources are weighted more heavily. This results in a delay of the shear wave arrival time.

Original language	English
Pages (from-to)	799-802
Number of pages	4
Journal	Ultrasonics
Volume	53
Issue number	3
DOIs	https://doi.org/10.1016/j.ultras.2012.11.007
State	Published - Mar 2013

Keywords

Ablation
Epicentral waveform
Laser ultrasound
Melting point
Thermoelastic

Access to Document

10.1016/j.ultras.2012.11.007

Cite this

@article{080bbdc5da2e443484fab8b59377cb32,

title = "Examination of the epicentral waveform for laser ultrasound in the melting regime",

abstract = "A laser ultrasonic source just below the ablation regime is examined by recording an epicentral waveform in a high purity tungsten sample. Using pulse energy as a parameter, a slight delay in the shear wave arrival time is observed upon transition to the melting regime. This phenomenon is attributed to a change in character of the ultrasonic source. In the thermoelastic regime, shear waves are generated by mode conversion at the sample surface of longitudinal waves emanating from subsurface sources. Just above the melting threshold, a molten pool forms in the center of the generation volume. Shear waves are not supported by the molten pool. As a result, shear waves generated from off-axis thermoelastic sources are weighted more heavily. This results in a delay of the shear wave arrival time.",

keywords = "Ablation, Epicentral waveform, Laser ultrasound, Melting point, Thermoelastic",

author = "Reese, {S. J.} and Utegulov, {Z. N.} and F. Farzbod and Schley, {R. S.} and Hurley, {D. H.}",

year = "2013",

month = mar,

doi = "10.1016/j.ultras.2012.11.007",

language = "English",

volume = "53",

pages = "799--802",

journal = "Ultrasonics",

issn = "0041-624X",

publisher = "Elsevier B.V.",

number = "3",

}

TY - JOUR

T1 - Examination of the epicentral waveform for laser ultrasound in the melting regime

AU - Reese, S. J.

AU - Utegulov, Z. N.

AU - Farzbod, F.

AU - Schley, R. S.

AU - Hurley, D. H.

PY - 2013/3

Y1 - 2013/3

N2 - A laser ultrasonic source just below the ablation regime is examined by recording an epicentral waveform in a high purity tungsten sample. Using pulse energy as a parameter, a slight delay in the shear wave arrival time is observed upon transition to the melting regime. This phenomenon is attributed to a change in character of the ultrasonic source. In the thermoelastic regime, shear waves are generated by mode conversion at the sample surface of longitudinal waves emanating from subsurface sources. Just above the melting threshold, a molten pool forms in the center of the generation volume. Shear waves are not supported by the molten pool. As a result, shear waves generated from off-axis thermoelastic sources are weighted more heavily. This results in a delay of the shear wave arrival time.

AB - A laser ultrasonic source just below the ablation regime is examined by recording an epicentral waveform in a high purity tungsten sample. Using pulse energy as a parameter, a slight delay in the shear wave arrival time is observed upon transition to the melting regime. This phenomenon is attributed to a change in character of the ultrasonic source. In the thermoelastic regime, shear waves are generated by mode conversion at the sample surface of longitudinal waves emanating from subsurface sources. Just above the melting threshold, a molten pool forms in the center of the generation volume. Shear waves are not supported by the molten pool. As a result, shear waves generated from off-axis thermoelastic sources are weighted more heavily. This results in a delay of the shear wave arrival time.

KW - Ablation

KW - Epicentral waveform

KW - Laser ultrasound

KW - Melting point

KW - Thermoelastic

UR - http://www.scopus.com/inward/record.url?scp=84873725561&partnerID=8YFLogxK

U2 - 10.1016/j.ultras.2012.11.007

DO - 10.1016/j.ultras.2012.11.007

M3 - Article

C2 - 23259982

AN - SCOPUS:84873725561

SN - 0041-624X

VL - 53

SP - 799

EP - 802

JO - Ultrasonics

JF - Ultrasonics

IS - 3

ER -

Examination of the epicentral waveform for laser ultrasound in the melting regime

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this