Development of an atomic mobility database for disordered and ordered fcc phases in multicomponent Al alloys: focusing on binary systems

2013 ◽  
Vol 104 (2) ◽  
pp. 135-148 ◽  
Author(s):  
Dandan Liu ◽  
Lijun Zhang ◽  
Yong Du ◽  
Senlin Cui ◽  
Wanqi Jie ◽  
...  
Keyword(s):  
Binary Systems ◽  
Al Alloys ◽  
Atomic Mobility ◽  
Mobility Database

A New Diffusivity Database for Multi-Component Al Alloys: Focusing on Ternary Systems and its Effect on Microstructure Evolution during Solidification

2014 ◽  
Vol 794-796 ◽  
pp. 611-616 ◽  
Author(s):  
Li Jun Zhang ◽  
Dan Dan Liu ◽  
Wei Bin Zhang ◽  
Shao Qing Wang ◽  
Ying Tang ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Hybrid Approach ◽  
Ternary Systems ◽  
Atomic Mobility ◽  
First Principles Calculations ◽  
Liquid Phases ◽  
Diffusion Controlled ◽  
Mobility Database ◽  
Diffusion Paths ◽  
Diffusion Properties

A new atomic mobility database for Fcc_A1, L12, Bcc_A2, Bcc_B2, and liquid phases in the Al-Cu-Fe-Mg-Mn-Ni-Si-Zn system has been established via a hybrid approach of experiment, first-principles calculations and DICTRA (DIffusion Controlled TRAnsformation) software, focusing on the atomic mobility parameters in ternary systems. Various diffusivities can be computed as a function of temperature and composition. The reliability of this diffusivity database is further validated by comparing the calculated and measured diffusion properties in a series of ternary and quaternary diffusion couples, including concentration profiles, diffusion paths, interdiffusion fluxes, and so on. The effect of the diffusivity database on microstructure evolution during solidification is demonstrated by the phase field simulation of primary (Al) grains in Al356.1 alloy. The simulation results indicate that such accurate diffusivity database is highly needed for the quantitative simulation of microstructural evolution during solidification.

scholarly journals An Effective Strategy to Maintain the CALPHAD Atomic Mobility Database of Multicomponent Systems and Its Application to Hcp Mg–Al–Zn–Sn Alloys

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 283
Author(s):  
Ting Cheng ◽  
Jing Zhong ◽  
Lijun Zhang
Keyword(s):  
Numerical Method ◽  
Traditional Method ◽  
The Self ◽  
Multicomponent Systems ◽  
Atomic Mobility ◽  
Effective Strategy ◽  
Mobility Database ◽  
Self Consistent ◽  
New Strategy ◽  
Comprehensive Comparison

In this paper, a general and effective strategy was first developed to maintain the CALPHAD atomic mobility database of multicomponent systems, based on the pragmatic numerical method and freely accessible HitDIC software, and then applied to update the atomic mobility descriptions of the hcp Mg–Al–Zn, Mg–Al–Sn, and Mg–Al–Zn–Sn systems. A set of the self-consistent atomic mobility database of the hcp Mg–Al–Zn–Sn system was established following the new strategy presented. A comprehensive comparison between the model-predicted composition–distance profiles/inter-diffusivities in the hcp Mg–Al–Zn, Mg–Al–Sn, and Mg–Al–Zn–Sn systems from the presently updated atomic mobilities and those from the previous ones that used the traditional method indicated that significant improvement can be achieved utilizing the new strategy, especially in the cases with sufficient experimental composition–distance profiles and/or in higher-order systems. Furthermore, it is anticipated that the proposed strategy can serve as a standard for maintaining the CALPHAD atomic mobility database in different multicomponent systems.

Interdiffusion and Atomic Mobility for Face-Centered-Cubic Co-Al Alloys

2011 ◽  
Vol 42 (9) ◽  
pp. 2542-2546 ◽  
Author(s):  
Y.-W. Cui ◽  
B. Tang ◽  
R. Kato ◽  
R. Kainuma ◽  
K. Ishida
Keyword(s):  
Al Alloys ◽  
Face Centered Cubic ◽  
Atomic Mobility ◽  
Face Centered

Interdiffusion and Atomic Mobility Studies in Ni-Rich fcc Ni-Co-Al Alloys

2016 ◽  
Vol 37 (3) ◽  
pp. 269-276 ◽  
Author(s):  
Y. L. Yang ◽  
Z. Shi ◽  
Y. S. Luo ◽  
Y. Lu ◽  
S. Y. Yang ◽  
...  
Keyword(s):  
Al Alloys ◽  
Atomic Mobility ◽  
Mobility Studies

Prediction of Hot Tearing Susceptibility for Mg-Zn-(Al) Alloys

2012 ◽  
Vol 509 ◽  
pp. 138-146 ◽  
Author(s):  
Le Zhou ◽  
Zheng Liu ◽  
Yuan Ding Huang ◽  
Ping Li Mao
Keyword(s):  
Magnesium Alloys ◽  
Binary Systems ◽  
Critical Time ◽  
Solidification Process ◽  
Al Alloys ◽  
Hot Tearing ◽  
Thermodynamic Simulations ◽  
Shape Curve ◽  
Work First ◽  
Hot Tearing Susceptibility

It is importance to be able to predict the hot tearing tendency for multicomponent magnesium alloys. Hot tearing is one of the most common and serious defects that occurs during the solidification of commercial magnesium alloys. Clyne and Davies correlated the susceptibility-composition relationship in binary systems based on the concept of the existence of critical time periods during the solidification process when the structure is most vulnerable to cracking. The present work first evaluates the hot tearing susceptibility (HTS) of binary Mg-Zn system using thermodynamic simulations based on Clyne-Davies’ model, a typical “λ shape” curve is obtained. And then a scaling factor is investigated to obtain the internal-consistent cracking susceptibility coefficient for further investigating the addition of aluminum on the HTS in the ternary Mg-Zn-Al system. The predicted hot tearing tendencies is consistent very well with the experimental results of the Mg-Zn binary system and Mg-Zn-Al ternary system.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

Quasi-Periodic Oscillations in Dwarf Novae

1979 ◽  
Vol 46 ◽  
pp. 77-88
Author(s):  
Edward L. Robinson
Keyword(s):  
Binary Systems ◽  
Outer Edge ◽  
Light Curves ◽  
Close Binary ◽  
Bright Spot ◽  
Dwarf Novae ◽  
Periodic Oscillations ◽  
High Frequencies ◽  
Short Period ◽  
Typical Time

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.

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