Effect of component substitution on the atomic dynamics in glass-forming binary metallic melts

2017 ◽  
Vol 96 (5) ◽  
Author(s):  
B. Nowak ◽  
D. Holland-Moritz ◽  
F. Yang ◽  
Th. Voigtmann ◽  
Z. Evenson ◽  
...  
Keyword(s):  
Glass Forming ◽  
Metallic Melts ◽  
Component Substitution

The Effect of Solute on the homogeneous Crystal Nucleation Frequency in Metallic Melts

1981 ◽  
Vol 9 ◽  
Author(s):  
C.V. Thompson ◽  
F. Spaepen
Keyword(s):  
Regular Solution Model ◽  
Solute Concentration ◽  
Crystal Nucleation ◽  
Qualitative Comparison ◽  
Glass Forming ◽  
Nucleation Frequency ◽  
Homogeneous Crystal ◽  
Complete Calculation ◽  
Metallic Melts ◽  
Approximate Expressions

ABSTRACTWe have made a complete calculation that extends the classical theory for crystal nucleation in pure melts to binary alloys. Using a regular solution model, we have developed approximate expressions for the free energy change upon crystallization as a function of solute concentration. They are used, together with model-based estimates of the interfacial tension, to calculate the nucleation frequency. The predictions of the theory for the maximum attainable undercooling are compared with existing experimental results for non-glass forming alloys. The theory is also applied to several easy glass-forming alloys (Pd-Si, Au-Si, Fe-B) for qualitative comparison with the present experimental experience on the ease of glass formation, and for assessment of the potential for formation of the glass in bulk.

Evaluation of Glass-Forming Ability for Metallic Melts by Phase Field Approach

2012 ◽  
Vol 490-495 ◽  
pp. 3129-3133 ◽  
Author(s):  
Gang Wang ◽  
De Chang Zeng ◽  
Zhong Wu Liu
Keyword(s):  
Phase Field ◽  
Amorphous Alloys ◽  
Solid Phase ◽  
Glass Forming Ability ◽  
Transformation Kinetics ◽  
Field Approach ◽  
Glass Forming ◽  
Temperature Transformation ◽  
Metallic Melts ◽  
Solid Phase Transition

Evaluation of glass-forming ability (GFA) is important in the development of amorphous alloys. Based on phase field theory, the kinetic model of liquid-to-solid phase transition is build, and the time-temperature-transformation (TTT) diagram is plotted according to the phase field simulations of isothermal phase transformation kinetics for a model system. Furthermore, the critical cooling rate for glass formation is calculated on the basis of the TTT curve and is taken as the intrinsic criteria of reflecting the GFA for metallic melts.

scholarly journals Microscopic insight into the origin of enhanced glass-forming ability of metallic melts on micro-alloying

2015 ◽  
Vol 107 (13) ◽  
pp. 131901 ◽  
Author(s):  
C. J. Chen ◽  
A. Podlesnyak ◽  
E. Mamontov ◽  
W. H. Wang ◽  
S. M. Chathoth
Keyword(s):  
Glass Forming Ability ◽  
Glass Forming ◽  
Metallic Melts ◽  
Insight Into

A slow atomic diffusion process in high-entropy glass-forming metallic melts

2018 ◽  
Vol 51 (14) ◽  
pp. 145301 ◽  
Author(s):  
Changjiu Chen ◽  
Kaikin Wong ◽  
Rithin P Krishnan ◽  
Jan P Embs ◽  
Suresh M Chathoth
Keyword(s):  
Diffusion Process ◽  
Atomic Diffusion ◽  
High Entropy ◽  
Glass Forming ◽  
Metallic Melts

Diffusion in Metallic Melts

2007 ◽  
Vol 266 ◽  
pp. 101-108 ◽  
Author(s):  
Axel Griesche ◽  
M.P. Macht ◽  
Günter Frohberg
Keyword(s):  
Glassy State ◽  
Diffusion Mechanism ◽  
Dynamic Simulations ◽  
Glass Forming ◽  
Temperature Diffusion ◽  
Binary Collisions ◽  
Collective Process ◽  
Thermodynamic Forces ◽  
Metallic Melts ◽  
Critical Temperature Tc

We present diffusion measurements in metallic melts measured by capillary techniques and results of molecular dynamic simulations. The investigated systems are the binary alloy AlNi20 and the multicomponent bulk glass-forming alloy Pd43Cu27Ni10P20. The temperature range of interest reached from the glassy state to the equilibrium melt. In the glassy as well as in the deeply supercooled state, below the critical temperature Tc of the mode-coupling, theory (MCT), diffusion is a highly collective atomic hopping process. Both investigated systems show around Tc a change in the diffusion mechanism. Above the liquidus temperature, diffusion in Pd43Cu27Ni10P20 is a collective process whereas in AlNi20 the atoms diffuse probably by uncorrelated binary collisions. The influence of thermodynamic forces on diffusion in the liquid state of AlNi20 can be described by the Darken equation with an additional temperature independent correction factor (“Manning”- factor).

Icosahedral order in glass-forming metallic melts

1994 ◽  
Vol 178 (1-2) ◽  
pp. 285-291 ◽  
Author(s):  
Jean-Marie Dubois ◽  
Frédéric Montoya ◽  
Christophe Back
Keyword(s):  
Glass Forming ◽  
Metallic Melts

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.

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