Low frequency internal friction in zinc single crystals

Dislocation-induced relaxations in different molybdenum single crystals were investigated by means of low-frequency internal friction measurements in the temperature range of 20–600 K. The results indicated that the appearance of the dislocation-induced relaxations strongly depends on the purity of the molybdenum, although the intrinsic dislocation relaxations appeared at about 100 K and 450 K in the high-purity molybdenum. The molybdenum containing a small amount of carbon did not exhibit the intrinsic dislocation relaxations but rather revealed a modulus increase due to the dislocation pinning caused by the dissolved carbon. When the molybdenum containing a small amount of carbon was annealed up to 700 K, a new relaxation peak appeared at about 450 K. The activation process for this relaxation indicated that it could be attributed to the relaxation due to a carbon-dislocation interaction. In addition, it was shown that the dislocation-induced relaxations in medium-purity molybdenum were small, which was attributed to the residual substitutional impurities in the molybdenum.

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Low-frequency internal-friction in alpha-brass single crystals in the microplastic region at(80÷300) K

Il Nuovo Cimento B ◽

10.1007/bf02722482 ◽

1976 ◽

Vol 33 (1) ◽

pp. 155-159 ◽

Cited By ~ 3

Author(s):

R. Threader ◽

P. Feltham

Keyword(s):

Internal Friction ◽

Single Crystals ◽

Low Frequency ◽

Alpha Brass

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Inelastic Behaviour of Ice Ih Single Crystals in the Low-Frequency Range Due to Dislocations

Journal of Glaciology ◽

10.1017/s0022143000033542 ◽

1978 ◽

Vol 21 (85) ◽

pp. 375-384 ◽

Cited By ~ 17

Author(s):

René Vassoille ◽

Christian Maï ◽

Joseph Perez

Keyword(s):

High Temperature ◽

Internal Friction ◽

Single Crystals ◽

Empirical Relation ◽

Low Frequency ◽

Frequency Range ◽

High Temperature Range ◽

Temperature Range ◽

Inelastic Behaviour ◽

Torsional Pendulum

Abstract The inelastic behaviour of ice Ih single crystals has been investigated by an inverted torsional pendulum in the low-frequency range. Three features are distinguished: (i) a relaxation peak previously observed by several authors in the higher-frequency range, (ii) an internal friction increasing with temperature in the high-temperature range (230–273 K), (iii) within this high-temperature range, internal friction becomes amplitude dependent, and this dependence becomes greater the greater the temperature. In this case, the internal friction has been interpreted in terms of movements of dislocations. Hence, the experimental results are interpreted with a model of internal friction based on an empirical relation for the velocity of dislocations. This model of internal friction is in fair agreement with experimental data . It is possible then to get an estimate of dislocation density. Hence it is shown that internal friction experiments can be useful in the study of the plastic behaviour of ice single crystals.

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Inelastic Behaviour of Ice Ih Single Crystals in the Low-Frequency Range Due to Dislocations

Journal of Glaciology ◽

10.3189/s0022143000033542 ◽

1978 ◽

Vol 21 (85) ◽

pp. 375-384

Author(s):

René Vassoille ◽

Christian Maï ◽

Joseph Perez

Keyword(s):

High Temperature ◽

Internal Friction ◽

Single Crystals ◽

Empirical Relation ◽

Low Frequency ◽

Frequency Range ◽

High Temperature Range ◽

Temperature Range ◽

Inelastic Behaviour ◽

Torsional Pendulum

AbstractThe inelastic behaviour of ice Ih single crystals has been investigated by an inverted torsional pendulum in the low-frequency range. Three features are distinguished:(i) a relaxation peak previously observed by several authors in the higher-frequency range,(ii) an internal friction increasing with temperature in the high-temperature range (230–273 K),(iii) within this high-temperature range, internal friction becomes amplitude dependent, and this dependence becomes greater the greater the temperature.In this case, the internal friction has been interpreted in terms of movements of dislocations. Hence, the experimental results are interpreted with a model of internal friction based on an empirical relation for the velocity of dislocations. This model of internal friction is in fair agreement with experimental data . It is possible then to get an estimate of dislocation density. Hence it is shown that internal friction experiments can be useful in the study of the plastic behaviour of ice single crystals.

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