-
[show abstract]
[hide abstract]
ABSTRACT: Zr60Ni21Al19 metallic glass rod, with a diameter of 8 mm, is manufactured by copper mold casting. The as-cast bulk metallic glass (BMG) exhibits nearly zero plastic strain, but a high strength of 1.88 GPa. The compression behavior of this new zirconium-base ternary BMG under high pressure at ambient temperature in a diamond-anvil cell instrument has been unraveled using energy dispersive x-ray diffraction with a synchrotron radiation source. The investigation shows that the amorphous structure of Zr60Ni21Al19 is stable under pressures up to 24.5 GPa at room temperature. According to the Bridgman equation of state, the bulk modulus B0 = 96 GPa has been obtained.
Journal of Materials Research. 08/2008; 23(09):2346 - 2349.
-
C. YANG,
C. Z. FAN,
Y. Z. JIA,
X. Y. WANG,
X. Y. ZHANG,
H. Y. WANG,
Q. JING, G. LI,
R. P. LIU,
L. L. SUN,
J. ZHANG,
W. K. WANG
[show abstract]
[hide abstract]
ABSTRACT: The damage characteristics of Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass under planar shock wave have been investigated by firing aluminum projectiles using a two-stage light
gas gun. The SEM results show that radial and symmetric cracks formed on the shocked plane of the sample at the impacted location
by aluminum projectile at the velocity of 2.7 km·s–1. Parallel shear crack/bands in the sublayer under the shocked plane were formed. For a better understanding of the response
features under shock wave, hypervelocity impact tests with conventional sphere aluminum projectiles were carried out. Besides
the same adiabatic shear crack/bands and crack propagations, craters were formed and lamination cracks occurred.
07/2006: pages 217-223;
-
[show abstract]
[hide abstract]
ABSTRACT: Embedded in a flux of dehydrated B2O3, melts of pure germanium were undercooled by repeated melting and solidification of the specimens within a differential scanning calorimeter facility. The highest undercooling obtained in this way was 190 K. The specific heat of the undercooled melt was measured by calorimetric diagnostics within the facility, and showed a linear dependence on temperature. The thermodynamic properties of germanium, such as the difference of Gibbs free energy, the difference of entropy, and the difference of enthalpy between the undercooled melt and the solid state, were derived from the measured specific heat.
Applied Physics Letters 07/2004; 85(4):558-560. · 3.84 Impact Factor
-
Journal of Materials Science Letters 01/2003; 22(3):171-173.
-
[show abstract]
[hide abstract]
ABSTRACT: The compression behaviour of a Pd 39 Ni 10 Cu 30 P 21 bulk metallic glass is investigated at room temperature up to 23.5 GPa using in situ high pressure energy dispersive x-ray diffraction with a synchrotron radiation source. Pressure induced structural relaxation of the bulk metallic glass is exhibited within the pressure range. It is found that below about 5 GPa, the existence of excess free volume contributes to rapid structural relaxation, which gives rise to rapid volumetric change. Under higher pressure, further relaxation results in structural stiffness.
J. Phys.: Condens. Matter. 01/2001; 13:5743-5748.
-
[show abstract]
[hide abstract]
ABSTRACT: Solidification of 0.1–1.0 mm diameter droplets of Al–50 at.%Si hypereutectic alloy was achieved in a 3 m drop tube. Phase morphologies of deeply etched sections of the solidified samples with different diameters are examined. With decreasing of the diameter of the droplets, refinement of the primary silicon phase is observed. A tendency for the primary silicon crystals to form granular morphology is found in the smaller samples. Stratified deposits of aluminum in the primary silicon along the silicon plate are evident in bigger samples, but less evident with decreasing of the sample size. Morphologies of Al–Si eutectics change from needle-like to short, blunt and worm-like forms with decreasing of the sample size. Through calculation of the nucleation rates at different sizes of the solidified sample and analyses of the crystal morphologies, grain refinement of the primary silicon can find its origins of copious nucleation during rapid cooling and solute-restriction to crystal growth.
Materials Science and Engineering: A.
