scholarly journals Internal Friction of Li7La3Zr2O12 Based Lithium Ionic Conductors

2016 ◽  
Vol 61 (1) ◽  
pp. 21-24
Author(s):  
X.P. Wang ◽  
L. Song ◽  
J. Hu ◽  
Y.P. Xia ◽  
Y. Xia ◽  
...  
Keyword(s):  
Internal Friction ◽  
Tetragonal Phase ◽  
Diffusion Processes ◽  
Low Frequency ◽  
Peak Height ◽  
Cubic Phase ◽  
Ionic Conductors ◽  
Internal Friction Peak ◽  
Lithium Ions ◽  
Diffusion Mechanisms

The diffusion mechanisms of lithium ions in tetragonal phase as well as in Al and Nb stabilized cubic Li7La3Zr2O12 compounds were investigated by low-frequency internal friction technique. In the cubic Li7La3Zr2O12 phase, a remarkable relaxation-type internal friction peak PC with a peak height up to 0.12 was observed in the temperature range from 15°C to 60°C. In the tetragonal phase however, the height of the PT peak dropped to 0.01. The obvious difference of the relaxation strength between the cubic and tetragonal phases is due to the different distribution of lithium ions in lattice, ordered in the tetragonal phase and disordered in the cubic phase. Based on the crystalline structure of the cubic garnet-type Li7La3Zr2O12 compound, it is suggested that the high internal friction peak in the cubic phase may be attributed to two diffusion processes of lithium ions: 96h↔96h and 96h↔24d.

scholarly journals Low-Frequency Mechanical Spectroscopy of Lanthanum Cobaltite Based Mixed Conducting Oxides

2016 ◽  
Vol 61 (3) ◽  
pp. 1733-1738
Author(s):  
Xiu Sheng Wu ◽  
Ju Fang Cao ◽  
Zhi Jun Chen ◽  
Wei Liu
Keyword(s):  
Phase Transition ◽  
Internal Friction ◽  
Domain Walls ◽  
Low Frequency ◽  
Partial Substitution ◽  
Cubic Phase ◽  
Mechanical Spectroscopy ◽  
Internal Friction Peak ◽  
Lanthanum Cobaltite ◽  
Conducting Oxides

Abstract The low-frequency mechanical spectra of lanthanum cobaltite based mixed conducting oxides have been measured using a computer-controlled inverted torsion pendulum. The results indicate that the internal friction spectra and shear modulus depend on the Sr doping contents (x). For undoped samples, no internal friction peak is observed. However, for La0.8Sr0.2CoO3‒δ, three internal friction peaks (P2, P3 and P4) are observed. In addition to these peaks, two more peaks (P0 and P1) are observed in La0.6Sr0.4CoO3‒δ. The P0 and P1 peaks show characteristics of a phase transition, while the P2, P3 and P4 peaks are of relaxation-type. Our analysis suggests that the P0 peak is due to a phase separation and the P1 peak is related to the ferromagnetic–paramagnetic phase transition. The P2, P3 and P4 peaks are associated with the motion of domain walls. The formation of this kind of domain structure is a consequence of a transformation from the paraelastic cubic phase to the ferroelastic rhombohedral phase. With partial substitution of Fe for Co, only one peak is observed, which is discussed as a result of different microstructure.

Development of the Snoek Anelastic Relaxation Correlated with Oxygen in β-Ti Alloys

2019 ◽  
Vol 298 ◽  
pp. 59-63 ◽  
Author(s):  
Zheng Cun Zhou ◽  
J. Du ◽  
S.Y. Gu ◽  
Y.J. Yan
Keyword(s):  
Internal Friction ◽  
Physical And Mechanical Properties ◽  
Peak Height ◽  
Relaxation Peak ◽  
Interstitial Oxygen ◽  
Internal Friction Peak ◽  
Β Phase ◽  
Ti Alloys ◽  
Interstitial Atoms ◽  
The Stability

The β-Ti alloys exhibit excellent shape memory effect and superelastic properties. The interstitial atoms in the alloys have important effect on their physical and mechanical properties. For the interstitial atoms, the internal friction technique can be used to detect their distributions and status in the alloys. The anelastic relaxation in β-Ti alloys is discussed in this paper. β-Ti alloys possesses bcc (body center body) structure. The oxygen (O) atoms in in the alloys is difficult to be removed. The O atoms located at the octahedral sites in the alloys will produce relaxation under cycle stress. In addition, the interaction between the interstitial atoms and substitute atoms, e.g., Nb-O,Ti-O can also produce relaxation. Therefore, the observed relaxational internal friction peak during the measuring of internal friction is widened. The widened multiple relaxation peak can be revolved into Debye,s elemental peaks in Ti-based alloys. The relaxation peak is associated with oxygen movements in lattices under the application of cycle stress and the interactions of oxygen-substitute atoms in metastable β phase (βM) phase for the water-cooled specimens and in the stable β (βS) phase for the as-sintered specimens. The damping peak height is not only associated with the interstitial oxygen, but also the stability and number of βM in the alloys.

A Study on Influence of Annealing and Aging on High Temperature Internal Friction in Al-Zr Alloy

2012 ◽  
Vol 535-537 ◽  
pp. 1027-1030
Author(s):  
Xiao Hui Cao ◽  
Yu Wang
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Grain Boundary ◽  
Low Frequency ◽  
Grain Boundary Sliding ◽  
High Temperature Side ◽  
Internal Friction Peak ◽  
Average Grain Size ◽  
Lower Temperature ◽  
Zr Alloy

By using a low frequency inverted torsion pendulum, the high temperature internal friction spectra of Al-0.02wt%Zr and Al-0.1wt%Zr alloys were investigated respectively. In Al-0.02wt%Zr alloy, the conventional grain boundary internal friction peak (Pg) is observed with some small unstable peaks. In Al-0.1wt%Zr alloy, the bamboo peak is observed to appear at the high temperature side of the conventional grain boundary internal friction peak. The conventional grain boundary internal friction peak decreased and moved to higher temperature. The bamboo peak owns an activation energy of 1.75eV. When average grain size exceeded the diameter of samples, Pb strength was reduced and its position was shifted to a lower temperature. Based on the grain boundary sliding model, Pg and Pb peaks were explained. Their dependence on annealing temperature and time was determined by considering the effects of contained Ce atoms and other impurities on the relaxation across grain boundary.

Internal Friction Influenced by Hydrogen in Super Duplex Stainless Steels

2005 ◽  
Vol 502 ◽  
pp. 345-350
Author(s):  
Toshio Kuroda ◽  
Katsuyuki Nakade ◽  
Kenji Ikeuchi
Keyword(s):  
Internal Friction ◽  
Stainless Steels ◽  
Sigma Phase ◽  
Peak Height ◽  
Phase Precipitation ◽  
Internal Friction Peak ◽  
Hydrogen Charging ◽  
Super Duplex Stainless Steels ◽  
Two Peaks ◽  
Friction Analysis

The influence of microstructure concerning sigma phase on hydrogen behavior was investigated by means of internal friction analysis. After hydrogen charging, a sharp significant internal friction peak by hydrogen in austenite of as-received specimen was observed at 245K for a frequency of 1.5Hz. However, the peak height in the specimen precipitated significant sigma phase was substantially lower than in as-received specimen since hydrogen in austenite have a concentration lower by sigma phase precipitation. In addition, the broadening and scattering of the internal friction peak was clearly identified by interaction between hydrogen and sigma phase. It means that the two peaks associated with hydrogen in the both sigma phase and austenite were considered to be overlapped. Consequently, it was clearly confirmed that hydrogen entered in the sigma phase lattice and hydrogen was also trapped at sigma/austenite interfaces.

Snoek Relaxation in bcc Metals and High Damping β-Ti Alloys

2009 ◽  
Vol 614 ◽  
pp. 175-180 ◽  
Author(s):  
Fu Xing Yin ◽  
Li Ming Yu ◽  
De Hai Ping ◽  
Satoshi Iwasaki
Keyword(s):  
Internal Friction ◽  
Temperature Stability ◽  
Relaxation Mechanism ◽  
Peak Height ◽  
Damping Capacity ◽  
Internal Friction Peak ◽  
Friction Mechanism ◽  
Bcc Metals ◽  
Temperature Position ◽  
Snoek Relaxation

The Snoek relaxation, a specific point-defect induced anelastic relaxation phenomenon, is characteristic of an internal friction peak in bcc metals with interstitial solutes. Such internal friction mechanism has not been applied in the development of high damping alloy while grain boundary and twin boundary featured anelastic relaxations are applied in some high damping alloys. In this paper, the fundamental principles and experimental results concerning the Snoek relaxation are reviewed, and the feasibility to apply the Snoek relaxation mechanism into high damping alloys is discussed. Due to the peak-shape behavior in the Snoek relaxation type damping, composition design of a high damping alloys should takes temperature position, broadness and also peak height into account. Ti-Nb-O and Ti-V-Cr-O alloys are designed and fabricated by CCLM casting in our laboratory. It is conformed that the damping behaviors of the alloys are of Snoek relaxation type showing obvious frequency and temperature dependence. While the broadened damping peak caused by the substitutional solutes is advantage to improve the temperature stability of damping capacity, a large concentration of interstitial solute and texture control are required to improve the reduced damping capacity.

Diffusion Processes in Low-Frequency Internal Friction of Crystalline Argon, Neon and Hydrogen

1991 ◽  
Vol 66-69 ◽  
pp. 1431-1434
Author(s):  
A.V. Leonteva ◽  
G.A. Marinin ◽  
A.Yu. Prokhorov ◽  
T.N. Anisimova
Keyword(s):  
Internal Friction ◽  
Diffusion Processes ◽  
Low Frequency

Internal Friction Study of Vacancy Hardening in B2 Fe Al Alloys

2012 ◽  
Vol 184 ◽  
pp. 81-86 ◽  
Author(s):  
Yoichi Nishino ◽  
Kazuya Ogawa ◽  
H. Tanaka
Keyword(s):  
Plastic Strain ◽  
Internal Friction ◽  
Strain Amplitude ◽  
Peak Height ◽  
Dislocation Motion ◽  
Al Alloys ◽  
Anomalous Increase ◽  
Internal Friction Peak ◽  
Quenching Temperature ◽  
Friction Study

nternal friction behaviour of B2 FeAl alloys has been examined to reveal the correlation of the microplasticity and thermal vacancies. The internal friction peak for Fe60Al40 appears at around 550 K, and the peak height increases with increasing quenching temperature. The curves of internal friction against the strain amplitude shift to larger strain amplitude as the quenching temperature increases. Analysis of the amplitude-dependent internal friction provides the plastic strain of the order of 10-9 as a function of effective stress on dislocation motion. It is found that the microflow stress at the plastic strain of 1×10-9 increases linearly with the square root of the net peak height. Remarkably, the microflow stress decreases with rising temperature but turns to increase above 500 K when measured after holding for 1 h at test temperatures. The anomalous increase in the microflow stress is caused by the creation of thermal vacancies at intermediate temperatures.

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