Internal Friction in Metallic Materials

High damping materials exhibiting a loss factor higher than 10-2 are generally considered as polymer or metallic materials. But, it will be interesting to consider ferroelectric or ferrimagnetic ceramics, in which internal friction can be due to the motion of ferroelectric or magnetic domains. High level of internal friction can be obtained in these ceramics in a given temperature range. In the case of ferroelectric ceramics, hard ferroelectrics, such as BaTiO3 or PZT, can show some relaxation peaks below the Curie temperature due the motion of domain walls and the interaction between the domain walls and the oxygen vacancies or cationic vacancies. In the case of ferrimagnetic ceramics, some anelastic manifestations due to the ferrimagnetic domain walls appear below the Curie Temperature TC. These peaks are linked to the interaction of domain walls with cation vacancies or cation interstitials or the lattice. Above the Curie temperature, a relaxation mechanism due to the exchange of cations Mn3+ and their vacancies on octahedral sites should occur.

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Mechanical Spectroscopy of High Pressure Torsion Deformed Fe-Based Alloys and Ti

Materials Science Forum ◽

10.4028/www.scientific.net/msf.503-504.745 ◽

2006 ◽

Vol 503-504 ◽

pp. 745-750 ◽

Cited By ~ 6

Author(s):

Igor S. Golovin ◽

Tatiana S. Pavlova ◽

C. Grusewski ◽

Julia Ivanisenko ◽

Dmitriy Gunderov

Keyword(s):

High Pressure ◽

Low Temperature ◽

Internal Friction ◽

Point Defect ◽

High Pressure Torsion ◽

Metallic Materials ◽

Mechanical Spectroscopy ◽

Early Stages ◽

Heating Up

Low temperature dislocation- and point defect-related anelasticity in high pressure torsion (HPT) deformed metallic materials bcc Fe-26Al, fcc Fe-36Ni, hcp Ti is studied by mechanical spectroscopy. Internal friction (IF) peaks, which correspond to these phenomena, have different stability against heating. Up to five IF peaks are recorded, at least some of these peaks can be classify as Hasiguti peaks. Mechanical spectroscopy gives a useful tool to study early stages of severely plastic deformed alloys study.

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Internal friction: Some considerations of the frequency response of rocks and other metallic and non-metallic materials

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(64)90029-4 ◽

1964 ◽

Vol 1 (2) ◽

pp. 231-254 ◽

Cited By ~ 2

Author(s):

Peter B. Attewell ◽

David Brentnall

Keyword(s):

Internal Friction ◽

Frequency Response ◽

Metallic Materials

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Internal Friction Data of Special Types of Metallic Materials (Tables)

Internal Friction in Metallic Materials - Springer Series in Materials Science ◽

10.1007/978-3-540-68758-0_5 ◽

2007 ◽

pp. 423-452

Keyword(s):

Internal Friction ◽

Metallic Materials

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SEM Examination of a Used Diamond Knife

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066310 ◽

1971 ◽

Vol 29 ◽

pp. 452-453

Author(s):

J. Temple Black

Keyword(s):

Electron Microscope ◽

High Voltage ◽

High Magnification ◽

Metallic Materials ◽

Wide Spread ◽

Thin Sections ◽

Transmission Electron ◽

Scanning Transmission ◽

Scanning Electron ◽

Diamond Knife

Since its introduction by Fernandez-Moran, the diamond knife has gained wide spread usage as a common material for cutting of thin sections of biological and metallic materials into thin films for examination in the transmission electron microscope. With the development of high voltage E.M. and scanning transmission E.M., microtomy applications will become increasingly important in the preparation of specimens. For those who can afford it, the diamond knife will thus continue to be an important tool to accomplish this effort until a cheaper but equally strong and sharp tool is found to replace the diamond, glass not withstanding.In Figs. 1 thru 3, a first attempt was made to examine the edge of a used (β=45°) diamond knife by means of the scanning electron microscope. Because diamond is conductive, first examination was tried without any coating of the diamond. However, the contamination at the edge caused severe charging during imaging. Next, a thin layer of carbon was deposited but charging was still extensive at high magnification - high voltage settings. Finally, the knife was given a light coating of gold-palladium which eliminated the charging and allowed high magnification micrographs to be made with reasonable resolution.

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Observation of secondary slip systems in tungsten bicrystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100112361 ◽

1984 ◽

Vol 42 ◽

pp. 478-479

Author(s):

J. R. Fekete ◽

R. Gibala

Keyword(s):

Stress Field ◽

Grain Boundaries ◽

Deformation Behavior ◽

Stress Axis ◽

Polycrystalline Materials ◽

Slip Systems ◽

Metallic Materials ◽

Twist Boundary ◽

Secondary Slip ◽

Plane Normal

The deformation behavior of metallic materials is modified by the presence of grain boundaries. When polycrystalline materials are deformed, additional stresses over and above those externally imposed on the material are induced. These stresses result from the constraint of the grain boundaries on the deformation of incompatible grains. This incompatibility can be elastic or plastic in nature. One of the mechanisms by which these stresses can be relieved is the activation of secondary slip systems. Secondary slip systems have been shown to relieve elastic and plastic compatibility stresses. The deformation of tungsten bicrystals is interesting, due to the elastic isotropy of the material, which implies that the entire compatibility stress field will exist due to plastic incompatibility. The work described here shows TEM observations of the activation of secondary slip in tungsten bicrystals with a [110] twist boundary oriented with the plane normal parallel to the stress axis.

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