Thickness and grain size monitoring in seamless tube-making process using laser ultrasonics

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Locating damages in a complex structure using one or two fixed ultrasonic transducers AIP Conference Proceedings 1706, 030020 (2016) Abstract. Management of thermal input to a small arms weapons system is a significant design and operational constraint. A collaborative project was initiated with the objective to measure non-intrusively the inner bore barrel temperature of a small arm during actual firing. The approach uses integrated ultrasonic transducers (IUTs) and the velocity temperature dependence of the longitudinal wave propagating through thickness. IUT is successfully implemented on a small arm at 3 locations and results from several firing tests are presented. The small but systematic increase in ultrasonic time delay of less than 1 ns after each firing shot is reliably measured, in agreement with a simple 1D model of heat conduction, and measured temperature rises are consistent with the thicknesses at the different locations. The evaluation of the peak inner bore temperatures using IUT and their validation using eroding surface thermocouples at the same locations in the barrel are discussed.

Section: -3mentioning

confidence: 99%

Non-intrusive measurement of inner bore temperature of small arms using integrated ultrasonic transducers

Lévesque¹,

Pimentel²,

Lord³

et al. 2016

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“…Using a large detection spot also allows removing the scattered field and, consequently, improves the SNR. Another way to overcome the diffraction correction is by using a single echo from the test sample and a reference echo from a sample of comparable thickness with negligible or known attenuation in the same measurement conditions [1]. In the experiment, the acoustic generation was realized by a Q-switched Nd:YAG laser operating at a wavelength of 1064 nm, with a pulse duration of 8 ns, and a pulse energy of about 1.5 J in the ablation regime.…”

Section: Pulse-echo Techniquementioning

confidence: 99%

“…where ω = 2πf , f is frequency, the exponent p is between 0.1 and 2 [1] and the exponent q is typically between 2.5 and 4 [2]. Also, it is found that the ratio between coefficients C abs and C sca is temperature dependent [3].…”

Section: Introductionmentioning

confidence: 99%

Laser-ultrasonic attenuation and absorption measurements in metals

Perton¹,

Lévesque²,

Moreau³

et al. 2012

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Laser-Ultrasonic attenuation and absorption measurements in metals NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=18968550&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=18968550&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCFor the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous. ABSTRACT. The attenuation of an acoustic wavefront in metals comes from scattering caused by grain anisotropy and random grain orientation and from absorption caused by mechanisms such as dislocation and magnetic domain motion. In this paper laser ultrasonics, with its non-contact and broadband characteristics, is used for measuring and separating these two attenuation contributions as a function of frequency. Results obtained from the well-known pulse-echo method and reverberation technique are presented first. Then, a more recent approach using a time-frequency analysis with zerogroup velocity (ZGV) resonances is considered. It is shown that the attenuation with scattering and absorption components is obtained by fitting the temporal decay of the resonances of the coherent field, and that only the absorption component is obtained from the temporal decay of the diffuse field between resonances. LASER-ULTRASONIC ATTENUATION AND ABSORPTION MEASUREMENTS IN METALS

“…1b). [6] Equation 2 shows the ratio between consecutive ∆t n where the velocity consequently is eliminated from the equation. …”

Section: Theory Thickness Measurement In Isotropic Materialsmentioning

confidence: 99%

Yield Strength Correlated to Directional Dependent Wave Velocities in Hot Rolled Steel Using Laser Ultrasonics

Engman¹,

Falkenström²,

Thompson³

et al. 2010