Effect of cooling rate on damping capacity of Fe–Cr based ferromagnetic metal alloy

2016 ◽  
Vol 650 ◽  
pp. 382-388 ◽  
Author(s):  
Hui Wang ◽  
Fu Wang ◽  
Jun Xiao ◽  
Yuan Wang ◽  
Ce Ma ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Ferromagnetic Metal ◽  
Metal Alloy ◽  
Damping Capacity

Effect of H-Doping on Damping Capacity of Various NiTi-Based Alloys at kHz Frequencies

2006 ◽  
Vol 128 (3) ◽  
pp. 254-259 ◽  
Author(s):  
B. Coluzzi ◽  
A. Biscarini ◽  
G. Mazzolai ◽  
F. M. Mazzolai ◽  
A. Tuissi
Keyword(s):  
Internal Friction ◽  
Twin Boundary ◽  
Room Temperature ◽  
Mechanical Energy ◽  
Noise Pollution ◽  
Metal Alloy ◽  
Maximum Efficiency ◽  
Damping Capacity ◽  
Good Opportunity ◽  
Hydrogen Doping

The internal friction Q−1 and the Young’s modulus E of NiTi based alloys have been measured as a function of temperature after various thermomechanical and hydrogen-doping treatments given to the materials. Hydrogen is found to play a major role introducing tall damping peaks associated with Snoek-type and H-twin boundary relaxations. Levels of Q−1 as high as 0.08 have been detected, which are among the highest to date measured in metal alloy systems. For appropriate alloy compositions, these peaks occur at around room temperature (for acoustical frequencies), thus providing a good opportunity to reduce machinery vibrations and noise pollution. In the paper, the conditions are highlighted under which maximum efficiency can be reached in the conversion of mechanical energy into heat.

Susceptibility of Damping Behavior to the Solidification Condition in the As-Cast M2052 High-Damping Alloy

2006 ◽  
Vol 319 ◽  
pp. 67-72 ◽  
Author(s):  
Fu Xing Yin ◽  
Satoshi Iwasaki ◽  
Takuya Sakaguchi ◽  
Kotobu Nagai
Keyword(s):  
Cooling Rate ◽  
Cast Alloy ◽  
Phase Transformation Temperature ◽  
Damping Capacity ◽  
Solidification Condition ◽  
Alloy Plate ◽  
Damping Behavior ◽  
Heat Treated ◽  
Damping Peak ◽  
Cast Plate

M2052 alloy is a MnCu based high damping alloy that shows high damping capacity and the superior workability. In the present work, the microstructure and damping behavior of the alloy in different solidification cooling rates are investigated with directionally cast alloy plate. For the variation of solidification cooling rate in the range of 250~10K/s, the secondary dendrite arm spacing of the cast alloy changes from 4 to 18mm and grain size varies in the range of 100~200mm except the surface regions and center regions in the cast plate. As compared to the worked and heat treated alloy, the as-cast alloy shows a high temperature damping above the average phase transformation temperature of the alloy irrespective to the solidification cooling rate. On the other hand, a higher damping peak is observed in the cast alloy which is attributed much to the twin boundary damping, however, the magnitudes of the damping peak are found to be varied corresponding to the respective solidification conditions.

Influence of Heat Treatment on the Damping Capacity of Fe-Ga Wires

2012 ◽  
Vol 629 ◽  
pp. 165-170
Author(s):  
Mei Ling Fang ◽  
Jie Zhu ◽  
Ji Heng Li ◽  
Chao Gan ◽  
Ming Ming Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Strain Amplitude ◽  
Annealing Temperature ◽  
Damping Capacity ◽  
Torsion Pendulum ◽  
Free Decay ◽  
Computer Controlled ◽  
Access To The Field ◽  
Noise And Vibration Reduction

The influence of heat treatment on damping capacity of (Fe83Ga17)99.5B0.5 wires was investigated using a computer-controlled automatic inverted torsion pendulum. The measurements have been carried out as a function of strain amplitude in free-decay mode. The microstructures of (Fe83Ga17)99.5B0.5 wires were also investigated to clarify the effects of heat treatment on the damping capacity. The results show that the annealing temperature affects the damping capacity of (Fe83Ga17)99.5B0.5 wires by varying the grain size. With increasing annealing temperature, the damping capacity is enhanced and becomes more sensitive to strain amplitude. There is no obvious difference in the structure of (Fe83Ga17)99.5B0.5 wires with different cooling rate which indeed affects the damping properties. Large cooling rate will help to get higher damping capacity. The Fe-Ga alloys show certain damping capacity and are worth paying close attention to enhance this property so as to get access to the field of unwanted noise and vibration reduction applications.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

Suppression of γ’ Precipitation in a Laser-Melted Nickel-Base Alloy

1977 ◽  
Vol 35 ◽  
pp. 270-271
Author(s):  
J. M. Walsh ◽  
J. C. Whittles ◽  
B. H. Kear ◽  
E. M. Breinan
Keyword(s):  
Cooling Rate ◽  
Base Alloy ◽  
Material Surface ◽  
Intimate Contact ◽  
Absorbed Power ◽  
Perfect Contact ◽  
Nickel Base ◽  
Rapidly Solidified ◽  
Limiting Case ◽  
The Heat Transfer Coefficient

Conventionally cast γ’ precipitation hardened nickel-base superalloys possess well-defined dendritic structures and normally exhibit pronounced segregation. Splat quenched, or rapidly solidified alloys, on the other hand, show little or no evidence for phase decomposition and markedly reduced segregation. In what follows, it is shown that comparable results have been obtained in superalloys processed by the LASERGLAZE™ method.In laser glazing, a sharply focused laser beam is traversed across the material surface at a rate that induces surface localized melting, while avoiding significant surface vaporization. Under these conditions, computations of the average cooling rate can be made with confidence, since intimate contact between the melt and the self-substrate ensures that the heat transfer coefficient is reproducibly constant (h=∞ for perfect contact) in contrast to the variable h characteristic of splat quenching. Results of such computations for pure nickel are presented in Fig. 1, which shows that there is a maximum cooling rate for a given absorbed power density, corresponding to the limiting case in which melt depth approaches zero.

Voids in Quenched Nickel

1968 ◽  
Vol 26 ◽  
pp. 266-267
Author(s):  
J. J. Laidler
Keyword(s):  
Electron Beam ◽  
Ambient Temperature ◽  
Cooling Rate ◽  
Three Dimensional ◽  
Cooling Curve ◽  
Polycrystalline Nickel ◽  
Quenching Temperature ◽  
Long Tail ◽  
Diffusion Pump

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

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