ENHANCED STRAIN AMPLITUDE DEPENDENCE OF INTERNAL FRICTION IN THE MIXED STATE OF NIOBIUM

1968 ◽  
Vol 13 (10) ◽  
pp. 362-364
Author(s):  
Edward J. Kramer ◽  
Charles L. Bauer
Keyword(s):  
Internal Friction ◽  
Strain Amplitude ◽  
Mixed State ◽  
Amplitude Dependence ◽  
Enhanced Strain

Internal Friction of Cast Graphite-Magnesium Composites

1988 ◽  
Vol 120 ◽  
Author(s):  
J. H. Armstrong ◽  
S. P. Rawal ◽  
M. S. Misra
Keyword(s):  
Internal Friction ◽  
Strain Amplitude ◽  
Friction Model ◽  
Piezoelectric Composite ◽  
Amplitude Dependence ◽  
Friction Behavior ◽  
Dislocation Densities ◽  
The Matrix ◽  
Composite Strain ◽  
Zr Alloy

AbstractInternal friction behavior in cast 8-ply [0°1 P55Gr/Mg-0.6%Zr alloy and P55Gr/Mg-1%Mn composites as a function of vibratory strain amplitude was measured at 80 kHz using a Marxtype piezoelectric composite oscillator. Both the matrix and composite exhibited strain amplitude independent internal friction below ε ≈ 10−6, while significant strain amplitude dependence was noted at higher strain levels. A maxima in damping was observed for most of the specimens tested. Heat treatment to enlarge grain size was found to increase both the strain amplitude independent and dependent internal friction of the composite. Strain amplitude dependence of the internal friction, including the existence of the maxima, was explained by the Granato-Lucke (G-L) dislocation internal friction model. Dislocation densities obtained from various TEM images from the fiber-matrix interface were compared to values predicted by G-L theory.

Internal Friction during Reverse Martensitic Transformation in Mn-Cu Alloy with 45 % Mn

2013 ◽  
Vol 738-739 ◽  
pp. 183-186 ◽  
Author(s):  
Galina Viktorovna Markova ◽  
Ekaterina Sergeevna Klyueva
Keyword(s):  
Heat Treatment ◽  
Martensitic Transformation ◽  
Low Temperature ◽  
Internal Friction ◽  
Temperature Dependence ◽  
Strain Amplitude ◽  
Physical Mechanism ◽  
Amplitude Dependence ◽  
Internal Friction Peak ◽  
Cu Alloy

The temperature and amplitude dependence of internal friction fcc Mn45Cu55 alloy aged at 400 °C were studied. Two low-temperature internal friction peak observed in the quenched state. Physical mechanism of the peaks was determined by the effect of frequency and strain amplitude on the temperature dependence of internal friction. The influence of the heat treatment to the internal friction of the investigated alloy was shown.

Stress Relaxation Behavior of Cu-Ni-P Alloys Evaluated from Amplitude-Dependent Internal Friction

2012 ◽  
Vol 184 ◽  
pp. 245-250
Author(s):  
Yasuhiro Aruga ◽  
Yoshiki Morikawa ◽  
Satoshi Tamaoka ◽  
Yoichi Nishino
Keyword(s):  
Stress Relaxation ◽  
Plastic Strain ◽  
Internal Friction ◽  
Strain Amplitude ◽  
Annealing Time ◽  
Three Dimensional ◽  
Atom Probe ◽  
Dislocation Motion ◽  
Amplitude Dependence ◽  
Stress Relaxation Behavior

The strain-amplitude dependence of internal friction in Cu-0.41Ni-0.11P (mass%) alloys has been evaluated to reveal the relation between the amplitude-dependent internal friction and the stress relaxation performance. Annealing at 250°C after cold rolling causes a suppression of the strain-amplitude dependence with increasing annealing time in the range between 10 s and 104 s. Analysis of the amplitude-dependent internal friction reveals 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 a constant level of plastic strain increases with increasing annealing time. This result is in line with the improvement in the stress relaxation performance but disagrees with a decrease in the tensile strength and yield stress after annealing. We believe that the increase in the microflow stress after annealing is caused by inhibition of dislocation motion due to Ni-P clusters, which were revealed by three-dimensional atom probe (3DAP) experiments.

Strain amplitude dependence of internal friction and strength of submicrometre-grained copper

1993 ◽  
Vol 171 (1-2) ◽  
pp. 143-149 ◽  
Author(s):  
R.R. Mulyukov ◽  
N.A. Akhmadeev ◽  
R.Z. Valiev ◽  
S.B. Mikhailov
Keyword(s):  
Internal Friction ◽  
Strain Amplitude ◽  
Amplitude Dependence

Effects of Pinning and Atomic Ordering on Damping Properties and Martensitic Transformation of Copper-Based Shape Memory Alloys

2012 ◽  
Vol 184 ◽  
pp. 366-371 ◽  
Author(s):  
S. Kustov ◽  
E. Cesari ◽  
Jan Van Humbeeck
Keyword(s):  
Martensitic Transformation ◽  
Internal Friction ◽  
Shape Memory ◽  
Long Range ◽  
Strain Amplitude ◽  
High Amplitude ◽  
Amplitude Dependence ◽  
Atomic Order ◽  
Damping Properties ◽  
Range Atomic Order

The effects of long-range atomic order and pinning of interfaces on anelastic properties of Cu-based martensite have been distinguished by means of studying strain amplitude dependences of internal friction and Young’s modulus defect, assuming that low-and high-amplitude stages of the strain amplitude dependence correspond to the oscillations within and beyond pinning atmospheres.

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