scholarly journals The Effects of Diffusional Couplings on Compositional Trajectories and Interfacial Free Energies During Phase Separation in a Quaternary Ni-Al-Cr-Re Model Superalloy

2021 ◽  
Author(s):  
Sung-Il Baik ◽  
Zugang Mao ◽  
Qingqiang Ren ◽  
Fei Xue ◽  
Carelyn E. Campbell ◽  
...  
Keyword(s):  
Phase Separation ◽  
Free Energies ◽  
Interfacial Free Energies

scholarly journals Phase separation during co-deposition of Al–Ge thin films

1992 ◽  
Vol 7 (3) ◽  
pp. 653-666 ◽  
Author(s):  
C.D. Adams ◽  
M. Atzmon ◽  
Y-T. Cheng ◽  
D.J. Srolovitz
Keyword(s):  
Thin Films ◽  
Phase Separation ◽  
Metastable Phase ◽  
Film Surface ◽  
Microstructure Development ◽  
Free Energies ◽  
Lateral Phase Separation ◽  
The Stability ◽  
Interfacial Free Energies ◽  
Film Substrate

We present the results of a combined experimental and theoretical investigation of phase separation and microstructure development in co-deposited Al–Ge thin films. For small film thicknesses and deposition temperatures above 150 °C the phase-separated films consist of an array of domains of the Al- and Ge-rich terminal phases (lateral phase separation). Films deposited at 100 °C or less contained one or both of the terminal phases plus a metastable phase. We show that the domain structure evolves during deposition in a manner consistent with a surface interdiffusion controlled process. As film thickness increases we observe a transition from the laterally phase-separated microstructure to a layered microstructure exhibiting phase separation perpendicular to the film/substrate interface (transverse phase separation), with Al segregating to the film surface. We present a thermodynamic argument based on the competition between surface and interfacial free energies to explain this transition. Finally, we discuss the stability of the transverse phase-separated microstructure in the thick-film limit in terms of the transport of Ge through the Al-rich surface layer.

Crystal-melt interfacial free energies in metals: fcc versus bcc

2004 ◽  
Vol 69 (2) ◽  
Author(s):  
D. Y. Sun ◽  
M. Asta ◽  
J. J. Hoyt ◽  
M. I. Mendelev ◽  
D. J. Srolovitz
Keyword(s):  
Free Energies ◽  
Interfacial Free Energies

Modeling of Liquid-Liquid Demixing Curve in Lead-Zinc Binary System

2018 ◽  
Vol 18 ◽  
pp. 49-54
Author(s):  
Naceur Amel ◽  
Adjadj Fouzia
Keyword(s):  
Mathematical Model ◽  
Free Energy ◽  
Phase Separation ◽  
Binary System ◽  
Free Energies ◽  
Common Tangent ◽  
Different Temperatures ◽  
Lead Zinc ◽  
The Common ◽  
Zn Alloys

In this work we discussed the modeling of the demixing curve in the liquid state in the Lead – Zinc binary system. We are interested to recalculate the free energies relating on Pb-Zn alloys for several temperatures based on the thermodynamic data collected in the bibliography. This calculation allows us to trace the curve of phase separation from a program after obtaining the mole fractions corresponding to the common tangent to the curve of the free energy with two minima at different temperatures. To do this, we used the Matlab 7.1 as the programming language and the Redlich-Kister polynomial as a mathematical model of development. The results obtained are very satisfactory by comparing them with those of the bibliography.

Studies of Ag/Fe Interfacial Free Energies by Biaxial Zero Creep Experiments

2003 ◽  
Vol 10 (05) ◽  
pp. 763-769 ◽  
Author(s):  
Bing An ◽  
Tong-Jun Zhang ◽  
Chao Yuan ◽  
Kun Cui
Keyword(s):  
Rf Magnetron Sputtering ◽  
Film Stress ◽  
Multilayer Thin Films ◽  
Free Energies ◽  
Stress Monitoring ◽  
Isothermal Process ◽  
Long Duration ◽  
Grain Distribution ◽  
Interface Free Energy ◽  
Interfacial Free Energies

Biaxial zero creep experiments based on the Josell model were performed on Ag/Fe multilayer thin films to determine their interfacial free energies. Various multilayer samples on stiff wafers prepared by RF magnetron sputtering were subjected to annealing of long duration at 550°C, while a substrate curvature technique was employed for real-time film stress monitoring. Sufficient plastic flow in films makes possible a zero creep equilibrium state to present during this isothermal process, and as a result the interfacial free energies in multilayer interfaces are equilibrated with the elastic strain energies arising from the substrate bending. There is no collapse in the annealed multilayer structures. They are still stably layer-built and exhibit a column grain distribution. XRD results show that Ag and Fe layers have (111) and (110) preferred orientations, respectively. In accordance with a revised Josell model, the equilibrium stresses were measured and the Ag (111)/ Fe (110) interface free energy at 550°C was found to be 0.97 ± 0.13 J/m 2.

Methods to extract interfacial free energies of flat and curved interfaces from computer simulations

2009 ◽  
Vol 177 (1) ◽  
pp. 103-127 ◽  
Author(s):  
M. Schrader ◽  
P. Virnau ◽  
D. Winter ◽  
T. Zykova-Timan ◽  
K. Binder
Keyword(s):  
Computer Simulations ◽  
Free Energies ◽  
Interfacial Free Energies

The Effect of Interfacial Free Energies on the Stability of Microlaminates

2000 ◽  
Vol 652 ◽  
Author(s):  
A. C. Lewis ◽  
A. B. Mann ◽  
D. van Heerden ◽  
D. Josell ◽  
T. P. Weihs
Keyword(s):  
Electron Microscopy ◽  
Grain Boundary ◽  
High Temperatures ◽  
Free Energies ◽  
Microstructural Stability ◽  
Creep Tests ◽  
Interfacial Energies ◽  
Transmission Electron ◽  
The Stability ◽  
Interfacial Free Energies

ABSTRACTLaminated composites with polycrystalline layers typically break down at high temperatures through grain boundary grooving and the pinch-off of individual layers. Such materials, when exposed to high temperatures, develop grooves where grain boundaries meet the interfaces between layers. The depths of the grooves are controlled by the ratios of grain boundary and interfacial free energies, γgb/γint. Depending on the dimensions of the grains, these grooves can extend through the entire layer, causing pinch-off at the grain boundary. This pinch-off destroys the layering and eventually leads to a gross coarsening of the microstructure. Because microstructural stability is critical to performance for most applications, the ability to understand and predict the stability of microlaminates is a necessary tool. An existing model of this capillarity-driven breakdown requires the interfacial free energies, γgb and γint, as input parameters. Both biaxial and uniaxial zero creep tests have been used in conjunction with transmission electron microscopy to measure these interfacial energies in Ag/Ni and Nb/Nb5Si3 microlaminates.

Temperature-Dependent Wettability of Water on a Nickel Surface at Pressurized Condition: A Molecular Dynamics Study

2019 ◽  
Author(s):  
Dong-Lei Zeng ◽  
Biao Feng ◽  
Jia-Wen Song ◽  
Li-Wu Fan
Keyword(s):  
Contact Angle ◽  
Hydrogen Bonds ◽  
Average Energy ◽  
Contact Angles ◽  
Nickel Surface ◽  
Free Energies ◽  
Water Droplets ◽  
Temperature Dependent ◽  
Interfacial Free Energies ◽  
Solid Liquid

Abstract Temperature-dependent wettability of water droplets on a metal surface in a pressurized environment is of great theoretical and practical significance. In this paper, molecular dynamic simulation is used to study this problem by relating the temperature-dependent apparent contact angles to the changes in solid-liquid and solid-vapor interfacial free energies and hydrogen bonds in the nano-sized water droplets with increasing the temperature. The temperature range of interest is set from 298 K to 538 K in a 20 K interval under a constant pressure of 7 MPa. The results show that the contact angle in general decreases with raising the temperature and decreasing trend can be divided into two sections with different slopes. The contact angle drops slowly when the temperature is below 458 K as a critical point. Beyond this point, the contact angle shows a much steeper decrease. The difference between solid-vapor and solid-liquid interfacial free energies is found to decrease slightly with temperature. Combining with that the surface tension drops with increasing the temperature, a decreasing trend of the contact angle is expected according to the Young’s equation. As the temperature increases, the number and average energy of the hydrogen bonds both decrease, and the hydrogen bonds tend to aggregate at the bottom of the nano-droplets.

On simulation methods to compute surface and interfacial free energies of disordered solids

2002 ◽  
Vol 116 (19) ◽  
pp. 8547 ◽  
Author(s):  
Gregory Grochola ◽  
Salvy P. Russo ◽  
Ian K. Snook ◽  
Irene Yarovsky
Keyword(s):  
Simulation Methods ◽  
Free Energies ◽  
Disordered Solids ◽  
Interfacial Free Energies
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