Duplex Solidification Mechanisms of Glass Forming Zr55Cu30Al10Ni5 Alloy During Electromagnetic Levitation Processing

2022 ◽  
Author(s):  
Shansen Xu ◽  
Wenhua Wu ◽  
Jian Chang ◽  
Sha Sha ◽  
Bingbo Wei
Keyword(s):  
Electromagnetic Levitation ◽  
Glass Forming

scholarly journals Demonstration of the effect of stirring on nucleation from experiments on the International Space Station using the ISS-EML facility

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. K. Gangopadhyay ◽  
M. E. Sellers ◽  
G. P. Bracker ◽  
D. Holland-Moritz ◽  
D. C. Van Hoesen ◽  
...  
Keyword(s):  
Fluid Flow ◽  
International Space Station ◽  
Space Station ◽  
Electromagnetic Levitation ◽  
Variable Density ◽  
Crystal Nucleation ◽  
Microgravity Environment ◽  
International Space ◽  
Glass Forming ◽  
Flux Model

AbstractThe effect of fluid flow on crystal nucleation in supercooled liquids is not well understood. The variable density and temperature gradients in the liquid make it difficult to study this under terrestrial gravity conditions. Nucleation experiments were therefore made in a microgravity environment using the Electromagnetic Levitation Facility on the International Space Station on a bulk glass-forming Zr57Cu15.4Ni12.6Al10Nb5 (Vit106), as well as Cu50Zr50 and the quasicrystal-forming Ti39.5Zr39.5Ni21 liquids. The maximum supercooling temperatures for each alloy were measured as a function of controlled stirring by applying various combinations of radio-frequency positioner and heater voltages to the water-cooled copper coils. The flow patterns were simulated from the known parameters for the coil and the levitated samples. The maximum nucleation temperatures increased systematically with increased fluid flow in the liquids for Vit106, but stayed nearly unchanged for the other two. These results are consistent with the predictions from the Coupled-Flux model for nucleation.

Thermal Expansion of Glass-Forming Zr-based Alloys in the Melt, the Undercooled Liquid and the Different Solid States

2000 ◽  
Vol 644 ◽  
Author(s):  
K. Samwer ◽  
B. Damaschke ◽  
M. Krause ◽  
P. Ryder
Keyword(s):  
Thermal Expansion ◽  
Ccd Camera ◽  
Electromagnetic Levitation ◽  
High Reactivity ◽  
Undercooled Liquid ◽  
Thermal Expansion Data ◽  
Glass Forming ◽  
Thermal Expansion Coefficients ◽  
Free Volume Model ◽  
Microgravity Conditions

AbstractThe thermal expansion coefficients of glass-forming Zr-based alloys were measured in the melt, the undercooled liquid and the glassy/crystalline state. Due to the high reactivity of the liquid material the experiments were performed containerlessly in an electrostatic levitator. We used an optical method where the samples were imaged with a high-resolution CCD- camera and the volume of the samples was evaluated by digital image processing. The coefficients of thermal expansion in the liquid and in the solid state could be determined from the volume versus temperature curves. The results can be compared with measurements in the electromagnetic levitation facility TEMPUS performed under microgravity conditions in the mission MSL-1 and ground based DMA-measurements. The thermal expansion data can be interpreted in terms of the free volume model.

Electron Microscopy of Silicon Nitride-Based Ceramics

1991 ◽  
Vol 49 ◽  
pp. 926-927
Author(s):  
Gareth Thomas
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Silicon Nitride ◽  
World Wide ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
High Temperature Strength ◽  
Sintering Additives ◽  
Glass Forming ◽  
Dense Product

Silicon nitride and silicon nitride based-ceramics are now well known for their potential as hightemperature structural materials, e.g. in engines. However, as is the case for many ceramics, in order to produce a dense product, sintering additives are utilized which allow liquid-phase sintering to occur; but upon cooling from the sintering temperature residual intergranular phases are formed which can be deleterious to high-temperature strength and oxidation resistance, especially if these phases are nonviscous glasses. Many oxide sintering additives have been utilized in processing attempts world-wide to produce dense creep resistant components using Si3N4 but the problem of controlling intergranular phases requires an understanding of the glass forming and subsequent glass-crystalline transformations that can occur at the grain boundaries.

The effect of an aluminum heat-sink layer on the laser-induced amorphization of SiOx/TeGeSn/SiOx phase-change recording films

1989 ◽  
Vol 47 ◽  
pp. 574-575
Author(s):  
Matthew R. Libera ◽  
Martin Chen
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Heat Sink ◽  
Multilayer Film ◽  
Glassy Phase ◽  
Film Structure ◽  
Glass Forming ◽  
Active Storage ◽  
Dielectric Layers ◽  
Amorphous States

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.

Crystallization in Al 88 RE 8 Ni 4 glass-forming alloys

2002 ◽  
Vol 82 (12) ◽  
pp. 2483-2497 ◽  
Author(s):  
T. K. Croat ◽  
A. K. Gangopadhyay ◽  
K. F. K Elton
Keyword(s):  
Glass Forming

Study of the ?-Mechanical Relaxation in Molecular Glass-Forming Liquids

1997 ◽  
Vol 7 (11) ◽  
pp. 1635-1650 ◽  
Author(s):  
A. Faivre ◽  
L. David ◽  
J. Perez
Keyword(s):  
Mechanical Relaxation ◽  
Glass Forming ◽  
Molecular Glass

DELORO 15, 21, 22, 25 ALLOYS

Alloy Digest ◽  
2011 ◽  
Vol 60 (4) ◽  
Keyword(s):  
Physical Properties ◽  
Powder Metal ◽  
Glass Forming ◽  
Nickel Base

Abstract DELORO 15, 21, 22, and 25 are prealloyed, gas-atomized, nickel-base powders for repair of glass-forming molds. This datasheet provides information on composition, physical properties, and hardness. It also includes information on powder metal forms. Filing Code: Ni-689. Producer or source: Stellite Coatings.

Predicting the Density-Scaling Exponent of a Glass-Forming Liquid from Prigogine-Defay Ratio Measurements

2011 ◽  
Author(s):  
Ditte Gundermann ◽  
Ulf R. Pedersen ◽  
Tina Hecksher ◽  
Nicholas P. Bailey ◽  
Bo Jakobsen ◽  
...  
Keyword(s):  
Scaling Exponent ◽  
Glass Forming
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