High‐Temperature Kilocycle Internal Friction in Al2O3 Single Crystals

1961 ◽  
Vol 32 (12) ◽  
pp. 2573-2579 ◽  
Author(s):  
R. J. Huber ◽  
G. S. Baker ◽  
P. Gibbs
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Single Crystals

High-Temperature Internal Friction Peak in Al–0.008 wt% Sn Single Crystals

1990 ◽  
Vol 121 (2) ◽  
pp. 475-481 ◽  
Author(s):  
G. Y. Tian ◽  
J. Z. Lu ◽  
S. P. Wu ◽  
L. D. Zhang
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Single Crystals ◽  
Internal Friction Peak

High-Temperature Mechanical Relaxations in Metals and Metallic Alloys

2006 ◽  
Vol 115 ◽  
pp. 87-98
Author(s):  
Andre Rivière
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Single Crystals ◽  
Strain Amplitude ◽  
Cold Work ◽  
Metallic Alloys ◽  
Continuous Heating ◽  
Dislocation Network ◽  
Relaxation Phenomena ◽  
Mechanical Spectroscopy

In spite of numerous works, the relaxation phenomena observed at high temperature (between room temperature and the melting temperature TM) are still under discussion. Because relaxation peaks were observed in single crystals, it is generally considered that the basis of the relaxation mechanism is linked to the dislocation network. The main difficulty for high temperature damping measurements is the great sensitivity of internal friction with several experimental parameters: the heating/cooling rate, maximal applied strain amplitude, sample purity, thermomechanical history of the sample, microstructure, etc. This sensitivity can explain the large scatter in experimental results published by various authors. Moreover, internal friction (IF) measurements performed during continuous heating or cooling and using an apparatus working at a quasi-static frequency, do not allow to completely describe the relaxation phenomena. On the contrary, isothermal mechanical spectroscopy (measurements of internal friction in a large frequency, temperature and maximal strain amplitude ranges) improves the experiments or evidences new relaxation effects. This is illustrated in this paper for various examples: slightly cold worked single crystals, polycrystals after a large cold work and recrystallization, non thermally activated peaks observed in metallic alloys, and relaxation peaks at very high temperature (above 0.9 TM).

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

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

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.

scholarly journals High Temperature Internal Friction in NiAl Single Crystals

1996 ◽  
Vol 06 (C8) ◽  
pp. C8-231-C8-234 ◽  
Author(s):  
M. Weller ◽  
M. Hirscher ◽  
E. Schweizer ◽  
H. Kronmüller
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Single Crystals

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

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.

scholarly journals INTERNAL FRICTION STUDY OF THE HIGH TEMPERATURE DISLOCATION MOBILITY IN Si SINGLE CRYSTALS

1987 ◽  
Vol 48 (C8) ◽  
pp. C8-101-C8-106 ◽  
Author(s):  
P. GADAUD ◽  
J. WOIRGARD ◽  
P. MAZOT ◽  
J. L. DEMENET ◽  
J. de FOUQUET
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Single Crystals ◽  
Dislocation Mobility ◽  
Friction Study
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