Search for High Damping Metallic Glasses

2006 ◽  
Vol 319 ◽  
pp. 151-156 ◽  
Author(s):  
Y. Hiki ◽  
M. Tanahashi ◽  
Shin Takeuchi
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Internal Friction ◽  
Metallic Glass ◽  
Room Temperature ◽  
Temperature Stability ◽  
Temperature Peak ◽  
High Temperature Side ◽  
Side Slope ◽  
Temperature Side

In a hydrogen-doped metallic glass, there appear low-temperature and high-temperature internal friction peaks respectively associated with a point-defect relaxation and the crystallization. The high-temperature-side slope of low-temperature peak and also the low-temperature-side slope of high-temperature peak enhance the background internal friction near the room temperature. A hydrogen-doped Mg-base metallic glass was proposed as a high-damping material to be used near and somewhat above the room temperature. Stability of the high damping was also checked.

Damping Capacity of Fe-Ga Alloys

2011 ◽  
Vol 228-229 ◽  
pp. 937-941 ◽  
Author(s):  
Fang Mei Ling ◽  
Jie Zhu ◽  
Li Ji Heng ◽  
Gao Xue Xu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Damping Capacity ◽  
Torsion Pendulum ◽  
Temperature Peak ◽  
Temperature Range ◽  
Computer Controlled ◽  
Increasing Temperature

The damping capacity of Fe-Ga rods and sheets has been studied using a computer-controlled automatic inverted torsion pendulum instruments in a wide temperature range in a series of frequency. The frequency and temperature has different influence on the damping capacity of solidified Fe83Ga17 rods and (Fe83Ga17)97.25Cr2B0.75 sheets. The damping capacity of all specimens increased with frequencies. The solidified Fe-Ga rods showed an obvious low-temperature peak and a potential high-temperature peak with increasing temperature. However, the damping capacity of Fe-Ga sheets kept steady in a wide temperature range and then rapidly increased on further heating above 400°C. Damping capacity of about 0.02 was obtained in both Fe-Ga rods and sheets at temperatures from room temperature to 500°C. Thus, The Fe-Ga alloys are considered to be a class of promising high damping alloys.

Early-life temperature modifies adult encapsulation response in an invasive ectoparasite

Parasitology ◽  
2015 ◽  
Vol 142 (10) ◽  
pp. 1290-1296 ◽  
Author(s):  
SIRPA KAUNISTO ◽  
LAURA HÄRKÖNEN ◽  
MARKUS J. RANTALA ◽  
RAINE KORTET
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Low Temperature ◽  
Blood Feeding ◽  
Life Cycles ◽  
Extreme Weather Events ◽  
Favourable Effect ◽  
Temperature Peak ◽  
Long Term Effects ◽  
High Temperature Peak

SUMMARYImmunity of parasites has been studied amazingly little, in spite of the fact that parasitic organisms, especially the arthropod parasites, need immunity to survive their own infections to successfully complete life cycles. Long-term effects of challenging environmental temperatures on immunity have remained unstudied in insects and parasites. Our study species, the deer ked (Lipoptena cervi; Linnaeus 1758), is an invasive, blood-feeding parasitic fly of cervids. Here, it was studied whether thermal stress during the pupal diapause stage could modify adult immunity (encapsulation capacity) in L. cervi. The effect of either a low temperature or high temperature peak, experienced during winter dormancy, on encapsulation response of active adult was tested. It was found that low temperature exposure during diapause, as long as the temperature is not too harsh, had a favourable effect on adult immunity. An abnormal, high temperature peak during pupal winter diapause significantly deteriorated the encapsulation capacity of emerged adults. The frequency and intensity of extreme weather events such as high temperature fluctuations are likely to increase with climate change. Thus, the climate change might have previously unknown influence on host-ectoparasite interactions, by affecting ectoparasite's immune defence and survival.

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.

Characteristics of Different Warm Mix Asphalt Compacted at Low Temperature

2011 ◽  
Vol 255-260 ◽  
pp. 3166-3170
Author(s):  
Li Ming Wang ◽  
Yi Qiu Tan ◽  
Zhen Wu Shi
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Crack Resistance ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Obvious Effect ◽  
Water Sensitivity ◽  
Active Additive ◽  
Surface Active ◽  
Temperature Crack

Additives on low temperature compaction and performances of compacted mixtures, the author devised low temperature environment compaction test, and then, comparison tests of volume parameters, high temperature stability, low temperature crack resistance and water sensitivity were conducted. Tests results showed that the wax additives and the surface-active additive can significantly contribute to mixtures low-temperature compactibility. The wax additive helps to improve high temperature stability obviously, and has no significant contribution to low temperature crack resistance and water sensitivity. The surface-active additive directly reduces water sensitivity, the wax additive indirectly plays the role of reducing water sensitivity by increasing the density of mixture, and the foam additive has no obvious effect on the water sensitivity.

Low Temperature Co-fired Ceramics Processing Parameters Governing the Performance of Miniaturized Force Sensors

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000411-000416
Author(s):  
Michael Weilguni ◽  
Walter Smetana ◽  
Goran Radosavljevic ◽  
Johann Nicolics ◽  
Werner Goebl ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Room Temperature ◽  
Processing Parameters ◽  
Gauge Factor ◽  
Force Sensors ◽  
Stabilized Zirconia ◽  
Temperature Coefficient Of Resistance ◽  
Microscope Images ◽  
Resistive Thick Film

For the development of miniaturized force sensors, built up in ceramics technology with piezo-resistive principle, the compatibility of the piezo-resistive thick-film paste with the substrate and termination paste has to be verified. This paper deals with the compatibility of the ESL 3414-A piezo-resistive paste on HTCC (high temperature co-fired ceramics) substrates (alumina as reference and the partially stabilized zirconia tape ESL 42013-A) as well as on LTCC (low temperature co-fired ceramics) substrates (Heraeus AHT01-005, AHT08-047, CT707; and CeramTec GC) under different manufacturing conditions. The sheet resistance at room temperature, the longitudinal gauge factor at room temperature and the temperature coefficient of resistance have been measured. The results are compared with microscope images showing cracks in distinct cases. Finally, the compatibility and thus applicability of the ESL 3414-A on the investigated substrates is evaluated.

STEPPED-COMBUSTION 14C DATING IN LOESS-PALEOSOL SEDIMENT

Radiocarbon ◽  
2020 ◽  
Vol 62 (5) ◽  
pp. 1209-1220
Author(s):  
Peng Cheng ◽  
Yunchong Fu
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Low Temperature ◽  
Organic Carbon ◽  
Room Temperature ◽  
14C Dating

ABSTRACTIn this study, low temperature (room temperature, 400°C LT) and high temperature (400–900°C HT) of bulk organic carbon samples were dated from two loess and paleosol profiles. The results showed that radiocarbon (14C) dates of the LT were younger than HT fractions, indicating effect of younger contamination from overlying layers. The δ13C variation of the HT fraction appears to respond much more sensitively to climate change, and 14C ages of HT fraction can produce reasonable 14C ages from a younger layer, but it is very difficult to obtain reliable 14C ages from older layer as a result of uncomplete removal of young carbon.

scholarly journals Study on Wear and Fatigue Performance of Two Types of High-Speed Railway Wheel Materials at Different Ambient Temperatures

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1152
Author(s):  
Lei MA ◽  
Wenjian WANG ◽  
Jun GUO ◽  
Qiyue LIU
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Speed ◽  
Room Temperature ◽  
Lamellar Spacing ◽  
Wear Loss ◽  
High Speed Railway ◽  
Railway Wheel ◽  
Ambient Temperatures ◽  
Railway Wheels

The wear and fatigue behaviors of two newly developed types of high-speed railway wheel materials (named D1 and D2) were studied using the WR-1 wheel/rail rolling–sliding wear simulation device at high temperature (50 °C), room temperature (20 °C), and low temperature (−30 °C). The results showed that wear loss, surface hardening, and fatigue damage of the wheel and rail materials at high temperature (50 °C) and low temperature (−30 °C) were greater than at room temperature, showing the highest values at low temperature. With high Si and V content refining the pearlite lamellar spacing, D2 presented better resistance to wear and fatigue than D1. Generally, D2 wheel material appears more suitable for high-speed railway wheels.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

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