Structure Instability of Metallic Glass Zr50Cu40Al10 in Low Temperature

2007 ◽  
Vol 539-543 ◽  
pp. 2100-2105
Author(s):  
Takeshi Fukami ◽  
A. Nanbu ◽  
M. Fukatani ◽  
Daisuke Okai ◽  
Y. Akeno ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistivity ◽  
Wave Propagation ◽  
Low Temperature ◽  
Metallic Glass ◽  
Room Temperature ◽  
Sound Propagation ◽  
Abrupt Increase ◽  
Mechanical Resonance ◽  
Abrupt Decrease

In order to examine mechanical properties of a metallic glass Zr50Cu40Al10 in low temperature below room temperature, the temperature T dependence of mechanical resonance of ultrasonic wave are measured. The mechanical resonance frequency in an as-quenched sample shows an abrupt increase at 200K for longitudinal wave and 160 K for transverse wave with decreasing T. After this abrupt increase, the sound propagation cannot be detected below these temperatures but the wave propagation is restored with increasing T and there is an abrupt decrease at 260K for the both wave modes. The similar hysteresis is observed in temperature dependence of the electrical resistivity. These suggest a kind of structure instability of Zr50Cu40Al10 in low temperature region.

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.

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.

scholarly journals Low-temperature degradation resistance and plastic deformation of ATZ ceramics stabilized by CaO

2021 ◽  
Vol 2103 (1) ◽  
pp. 012075
Author(s):  
AA Dmitrievskiy ◽  
DG Zhigacheva ◽  
VM Vasyukov ◽  
PN Ovchinnikov
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Phase Composition ◽  
Low Temperature ◽  
Uniaxial Compression ◽  
Calcium Oxide ◽  
Tetragonal Phase ◽  
Room Temperature

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.

Effect of mechanical-annealing on the mechanical properties of a Zr-based bulk metallic glass

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940052
Author(s):  
P. Deng ◽  
X. C. Wang ◽  
F. Zhang ◽  
X. M. Qin ◽  
P. Gao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Room Temperature ◽  
Constant Pressure ◽  
Aging Treatment ◽  
Model Material ◽  
Glass Forming ◽  
Plastic Stage

The mechanical-annealing referred in this work is also named pre-strain, which is widely investigated in TRIP steel, stainless steel, magnesium alloy and aluminum alloy. In this case, we used preloading to input energy into a bulk metallic glass (BMG) to observe the changes in the structure and mechanical properties. We selected Zr[Formula: see text]Co[Formula: see text]Al[Formula: see text] BMG as a model material owning to its outstanding glass forming ability and excellent mechanical properties. The samples were kept at a constant pressure of 1900, 1700 and 1500 MPa (below the yield strength) for 40, 55 and 70 h. The study found out that the density of those samples increased after being pre-loaded. Then, the samples underwent aging treatment at room-temperature for more than 30 days after unloading. After re-compressing the samples, the results show that the yield strength and fracture strength of the samples decreased, and the amplitude of the serrated plastic flow increased during the plastic stage. Our finding might have some implications for understanding the plastic deformation of BMGs.

Influence of Al-Cu-Mn-Fe-Ti Alloy Composition and Production Parameters of Extruded Semi-Finished Products on their Structure and Mechanical Properties

2017 ◽  
Vol 265 ◽  
pp. 456-462 ◽  
Author(s):  
P.L. Reznik ◽  
Mikhail Lobanov
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Thermal Treatment ◽  
Low Temperature ◽  
Room Temperature ◽  
High Temperature Strength ◽  
Ti Alloy ◽  
Low Temperature Annealing ◽  
Annealing Conditions ◽  
Concentration Changes

Studies have been conducted as to the effect of Cu, Mn, Fe concentration changes in Al-Cu-Mn-Fe-Ti alloy, the conditions of thermal and deformational treatment of ingots and extruded rods 40 mm in diameter on the microstructure, phase composition and mechanical properties. It has been determined that changing Al-6.3Cu-0.3Mn-0.17Fe-0.15Ti alloy to Al-6.5Cu-0.7Mn-0.11Fe-0.15Ti causes an increase in the strength characteristics of extruded rods at the room temperature both after molding and in tempered and aged conditions, irrespective of the conditions of thermal treatment of the initial ingot (low-temperature annealing 420 °С for 2 h, or high-temperature annealing at 530 °С for 12 h). Increasing the extruding temperature from 330 to 480 °С, along with increasing Cu, Mn and decreasing Fe in the alloy Al-Cu-Mn-Ti, is accompanied by the increased level of ultimate strength in a quenched condition by 25% to 410 MPa, irrespective of the annealing conditions of the original ingot. An opportunity to apply the Al-6.3Cu-0.3Mn-0.17Fe-0.15Ti alloy with low-temperature annealing at 420 °С for 2 h and the molding temperature of 330 °С has been found to produce rods where, in the condition of full thermal treatment (tempering at 535 °С + aging at 200 °С for 8 hours), a structure is formed that ensures satisfactory characteristics of high temperature strength by resisting to fracture for more than 100 hours at 300 °С and 70 MPa.

Room temperature mechanical properties of polycrystalline YbAl3, a promising low temperature thermoelectric material

2013 ◽  
Vol 35 ◽  
pp. 15-24 ◽  
Author(s):  
Robert D. Schmidt ◽  
Eldon D. Case ◽  
Gloria J. Lehr ◽  
Donald T. Morelli
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Thermoelectric Material ◽  
Room Temperature

Electron Transport Properties of Aluminium Substituted CuTi Amorphous Alloys

1997 ◽  
Vol 11 (03) ◽  
pp. 303-313 ◽  
Author(s):  
A. K. Bhatnagar ◽  
G. Fritsch ◽  
D. G. Naugle ◽  
R. Haberkern ◽  
M. Kandlbinder ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Electron Transport ◽  
Low Temperature ◽  
Amorphous Alloys ◽  
Room Temperature ◽  
Quantum Corrections ◽  
Spin Orbit ◽  
Electron Transport Properties ◽  
Temperature Coefficient Of Resistivity ◽  
Scattering Time

Room temperature electrical resistivity (ρ), temperature coefficient of resistivity (α) and Hall coefficient (R H ) of ( Cu 1-y Ti y)1-x Al x amorphous alloys, where y=0.36, 0.50 and 0.64 and x=0, 0.05 and 0.10 are presented. The low temperature dependence of resistivity and magnetoresistivity of a-( Cu 0.36 Ti 0.64)1-x Al x are also presented and discussed qualitatively in terms of quantum corrections. It is found that the addition of Al in a- Cu 0.36 Ti 0.64 alloy decreases the spin-orbit scattering time τ so .

Low Temperature Warm Forming of Magnesium ZEK 100 Sheets for Automotive Applications

2014 ◽  
Vol 783-786 ◽  
pp. 431-436 ◽  
Author(s):  
Xiao Ping Niu ◽  
Tim Skszek ◽  
Mark Fabischek ◽  
Alex Zak
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Process Parameters ◽  
Room Temperature ◽  
Warm Forming ◽  
Automotive Applications ◽  
Forming Process ◽  
Stamping Die ◽  
Automotive Parts ◽  
Volume Production

Cosma R&D investigated a low temperature warm forming process by which a magnesium ZEK 100 door inner part with a single-stage draw depth of 144 mm was successfully formed. The warm forming process is comprised of three steps: 1) heating pre-lubricated blanks in an oven at temperatures ranging from 215°C to 260 °C, 2) robotic transfer of the heated blank to a mechanical stamping press, 3) forming of the panel in room temperature stamping die at speed of about 160 mm/s. The effect of process parameters on the formability of the part, as well as, the post-forming properties including the mechanical properties, microstructure evolution and deformation thinning are also presented. The result indicates that Magnesium ZEK 100 exhibits superior low temperature warm formability over Magnesium AZ31B, and the developed warm forming process is promising and potential for volume production of magnesium automotive parts.

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