Intercrystalline Thermal Currents as a Source of Internal Friction

Randall, Robert H.; Rose, Franck; Zener, Clarence

doi:10.1103/physrev.56.343

Cited by 75 publications

(24 citation statements)

References 5 publications

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“…For the case of intercrystalline thermal currents, this was confirmed experimentally as early as 1939 [7] (as cited in [1,3]); however, until presently we did not know of any related observation of such an intergranular effect due to atomic diffusion. Accordingly, dynamic mechanical damping peaks by atomic diffusion are usually identified with short-range reorientation processes on the atomic scale analogous to the well-known Snoek relaxation effect [3,8], but not with any kind of long-range diffusion.…”

Section: Mechanical Damping By Intercrystalline Diffusion Of Hydrogenmentioning

confidence: 51%

Mechanical Damping by Intercrystalline Diffusion of Hydrogen in Metallic Polycrystals

2000

Phys. Rev. Lett.

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Anelastic relaxation by intercrystalline atomic diffusion-analogous to thermal diffusion (i.e., thermoelastic) effects but never observed hitherto-was recently suggested as a new mechanism to explain part of the hydrogen damping spectra in intermetallic compounds. A critical experimental test of this model is now presented using a Zr65Cu17.5Ni10Al7.5 alloy, which allows for a quantitative kinetic analysis in comparison to a closely related reorientation process. The results are in full agreement with the predictions of the model and clearly corroborate the proposed "intercrystalline Gorsky effect" as a new type of mechanical damping in sufficiently fine-grained polycrystals.

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Section: Mechanical Damping By Intercrystalline Diffusion Of Hydrogenmentioning

confidence: 51%

Mechanical Damping by Intercrystalline Diffusion of Hydrogen in Metallic Polycrystals

2000

Phys. Rev. Lett.

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“…More recently, Zener's analysis of homogenous, isotropic beams has been extended in multiple directions and there are now over 350 significant publications on this topic. A selection of the literature includes models to account for the effects of structural boundaries [47,48]; polycrystalline grain structure [49,50]; layered composite architecture [51][52][53]; electrostatic actuation [54]; and geometry (plates [54,55], slotted, channeled, and hollow beams [56][57][58], double-paddle oscillators [63], and bulk-mode, ring-mode, and disc-mode resonators [59]). Using these models, the design space can be explored to formulate detailed guidelines for selecting geometries, structures, modes, materials, and frequencies to minimize thermoelastic damping.…”

Section: Thermoelastic Dampingmentioning

confidence: 99%

Design strategies for controlling damping in micromechanical and nanomechanical resonators

2014

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Damping is a critical design parameter for miniaturized mechanical resonators usedin microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS),optomechanical systems, and atomic force microscopy for a large and diverse set ofapplications ranging from sensing, timing, and signal processing to precisionmeasurements for fundamental studies of materials science and quantum mechanics.This paper presents an overview of recent advances in damping from the viewpointof device design. The primary goal is to collect and organize methods, tools, andtechniques for the rational and effective control of linear damping in miniaturizedmechanical resonators. After reviewing some fundamental links between dynamicsand dissipation for systems with small linear damping, we explore the space ofdesign and operating parameters for micromechanical and nanomechanicalresonators; classify the mechanisms of dissipation into fluid–structure interactions(viscous damping, squeezed-film damping, and acoustic radiation), boundarydamping (stress-wave radiation, microsliding, and viscoelasticity), and materialdamping (thermoelastic damping, dissipation mediated by phonons and electrons,and internal friction due to crystallographic defects); discuss strategies for minimizingeach source using a combination of models for dissipation and measurements of material properties; and formulate design principles for low-loss micromechanical and nanomechanical resonators

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“…Hence thermal currents flow across the grain boundaries, giving rise to an internal friction Downloaded by [Michigan State University] at 16:33 09 January 2015 D. tt, Niblett and J. Wilks on which is a function of the grain size. An expression for this friction, given by Zener (1938), has been verified by Randall et al (1939) using brass with a wide range of grain sizes at 6, 12 and 36kc/s.…”

Section: Dislocation Damping In Metalsmentioning

confidence: 99%