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Title: Surface acoustic wave studies of hydrogen entry into a Ni-base alloy

Abstract

Rayleigh acoustic waves were propagated along the surface of a sheet sample of a Ni alloy while the alloy was undergoing electrolytic charging with hydrogen. The waves were propagated, at frequencies from 2 to 15 MHz, from a transmitting to a receiving transducer, and their attenuation and velocity were monitored. A number of experiments was conducted to ensure that Rayleigh conditions were met and that extraneous results due to such effects as passive film changes and bubble formation were minimal. During cathodic polarization, wave velocity and attenuation decreased. The attenuation decrease followed two stages: an instantaneous one, probably due to polarization effects in the electrolyte, and a gradual one associated with the entry of hydrogen into the alloy. Both the instantaneous and gradual decreases were reversible and were recovered when polarization was removed. The kinetics of the recovery of the gradual component of attenuation were described by the Granato-Hikata-Luecke model for unpinning of dislocations by point defects. All results indicated that the surface wave technique was sensitive to hydrogen atom entry into the surface and that the entering atoms migrated to and pinned dislocations within a layer of thickness much less than the Rayleigh wavelength.

Authors:
;
Publication Date:
Research Org.:
Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
OSTI Identifier:
6543963
Resource Type:
Journal Article
Journal Name:
J. Appl. Phys.; (United States)
Additional Journal Information:
Journal Volume: 52:4
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; HYDROGEN; ABSORPTION; NICKEL ALLOYS; ACOUSTICS; SORPTIVE PROPERTIES; ATTENUATION; DATA; DISLOCATIONS; ELECTROLYSIS; KINETICS; MHZ RANGE; POINT DEFECTS; RAYLEIGH WAVES; SURFACES; TRANSDUCERS; VELOCITY; WAVE PROPAGATION; ALLOYS; CRYSTAL DEFECTS; CRYSTAL STRUCTURE; ELEMENTS; FREQUENCY RANGE; INFORMATION; LINE DEFECTS; LYSIS; NONMETALS; SEISMIC SURFACE WAVES; SEISMIC WAVES; SURFACE PROPERTIES; 360603* - Materials- Properties

Citation Formats

Lunarska, E, and Fiore, N F. Surface acoustic wave studies of hydrogen entry into a Ni-base alloy. United States: N. p., 1981. Web. doi:10.1063/1.329066.
Lunarska, E, & Fiore, N F. Surface acoustic wave studies of hydrogen entry into a Ni-base alloy. United States. doi:10.1063/1.329066.
Lunarska, E, and Fiore, N F. Wed . "Surface acoustic wave studies of hydrogen entry into a Ni-base alloy". United States. doi:10.1063/1.329066.
@article{osti_6543963,
title = {Surface acoustic wave studies of hydrogen entry into a Ni-base alloy},
author = {Lunarska, E and Fiore, N F},
abstractNote = {Rayleigh acoustic waves were propagated along the surface of a sheet sample of a Ni alloy while the alloy was undergoing electrolytic charging with hydrogen. The waves were propagated, at frequencies from 2 to 15 MHz, from a transmitting to a receiving transducer, and their attenuation and velocity were monitored. A number of experiments was conducted to ensure that Rayleigh conditions were met and that extraneous results due to such effects as passive film changes and bubble formation were minimal. During cathodic polarization, wave velocity and attenuation decreased. The attenuation decrease followed two stages: an instantaneous one, probably due to polarization effects in the electrolyte, and a gradual one associated with the entry of hydrogen into the alloy. Both the instantaneous and gradual decreases were reversible and were recovered when polarization was removed. The kinetics of the recovery of the gradual component of attenuation were described by the Granato-Hikata-Luecke model for unpinning of dislocations by point defects. All results indicated that the surface wave technique was sensitive to hydrogen atom entry into the surface and that the entering atoms migrated to and pinned dislocations within a layer of thickness much less than the Rayleigh wavelength.},
doi = {10.1063/1.329066},
journal = {J. Appl. Phys.; (United States)},
number = ,
volume = 52:4,
place = {United States},
year = {1981},
month = {4}
}