Critical Assessment of the Al-Ti-Zr System

Abstract Only within the last couple of years, complete isothermal sections for the Al-Ti-Zr system have been determined. Up to then there had been several investigations, but these were limited to the Ti-Zr and Ti-Al sides and the Ti- and Al corners of the system. Also recently the system has been evaluated by thermodynamic ab initio calculations and CALPHAD-type (CALculation of PHAse Diagrams) modelling. As Al-Ti-Zr alloys are of interest for a variety of applications and as the last assessment has been performed more than 15 years ago, this new critical evaluation of the existing literature about phase equilibria in the Al-Ti-Zr system has been performed.

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Ab initio calculations of the phase diagrams of tin and lead under pressures up to a few TPa

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/abbbc5 ◽

2020 ◽

Vol 33 (3) ◽

pp. 035402

Author(s):

N A Smirnov

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Phase Diagrams

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Electronic, magnetic properties and phase diagrams of system with Fe4N compound: An ab initio calculations and Monte Carlo study

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2018.01.038 ◽

2018 ◽

Vol 453 ◽

pp. 220-225 ◽

Cited By ~ 14

Author(s):

R. Masrour ◽

A. Jabar ◽

E.K. Hlil

Keyword(s):

Monte Carlo ◽

Magnetic Properties ◽

Ab Initio Calculations ◽

Ab Initio ◽

Phase Diagrams ◽

Monte Carlo Study

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Critical Evaluation of Various Spontaneous Polarization Models and Induced Electric Fields in III-Nitride Multi-Quantum Wells

Materials ◽

10.3390/ma14174935 ◽

2021 ◽

Vol 14 (17) ◽

pp. 4935

Author(s):

Ashfaq Ahmad ◽

Pawel Strak ◽

Kamil Koronski ◽

Pawel Kempisty ◽

Konrad Sakowski ◽

...

Keyword(s):

Ab Initio Calculations ◽

Quantum Wells ◽

Ab Initio ◽

Electric Fields ◽

Spontaneous Polarization ◽

Berry Phase ◽

Critical Evaluation ◽

Theoretical Data ◽

Polarization Difference ◽

Binary Compounds

In this paper, ab initio calculations are used to determine polarization difference in zinc blende (ZB), hexagonal (H) and wurtzite (WZ) AlN-GaN and GaN-InN superlattices. It is shown that a polarization difference exists between WZ nitride compounds, while for H and ZB lattices the results are consistent with zero polarization difference. It is therefore proven that the difference in Berry phase spontaneous polarization for bulk nitrides (AlN, GaN and InN) obtained by Bernardini et al. and Dreyer et al. was not caused by the different reference phase. These models provided absolute values of the polarization that differed by more than one order of magnitude for the same material, but they provided similar polarization differences between binary compounds, which agree also with our ab initio calculations. In multi-quantum wells (MQWs), the electric fields are generated by the well-barrier polarization difference; hence, the calculated electric fields are similar for the three models, both for GaN/AlN and InN/GaN structures. Including piezoelectric effect, which can account for 50% of the total polarization difference, these theoretical data are in satisfactory agreement with photoluminescence measurements in GaN/AlN MQWs. Therefore, the three models considered above are equivalent in the treatment of III-nitride MQWs and can be equally used for the description of the electric properties of active layers in nitride-based optoelectronic devices.

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Reliable electrochemical phase diagrams of magnetic transition metals and related compounds from high-throughput ab initio calculations

npj Materials Degradation ◽

10.1038/s41529-019-0088-z ◽

2019 ◽

Vol 3 (1) ◽

Cited By ~ 9

Author(s):

Liang-Feng Huang ◽

James M. Rondinelli

Keyword(s):

Transition Metals ◽

Ab Initio Calculations ◽

Ab Initio ◽

Phase Diagrams ◽

High Throughput ◽

Magnetic Transition ◽

Related Compounds

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Ab initio and CALPHAD-type thermodynamic investigation of the Ti-Al-Zr system

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb181022039d ◽

2019 ◽

Vol 55 (3) ◽

pp. 427-437 ◽

Cited By ~ 6

Author(s):

Z.-X. Deng ◽

D.-P. Zhao ◽

Y.-Y. Huang ◽

L.-L. Chen ◽

H. Zou ◽

...

Keyword(s):

Experimental Data ◽

Phase Equilibria ◽

Ab Initio Calculations ◽

Ab Initio ◽

Thermodynamic Parameters ◽

Vertical Section ◽

Calphad Approach ◽

Alloying Element ◽

Formation Enthalpies ◽

End Members

Ti?Al based alloys have been widely used in the aeronautics and aerospace. Adding alloying element Zr can significantly improve their high-temperature endurance and corrosion resistance. To investigate the influence of the addition of element Zr on the properties of the Ti?Al system, ab initio calculations and the CALPHAD (CALculation of PHAse Diagrams) method were used to evaluate the Ti?Al?Zr ternary system. Ab initio calculations were carried out to calculate the formation enthalpies of intermetallic compounds and end-members. CALPHAD approach was employed to optimize the thermodynamic parameters based on experiments. The experimental data of phase equilibria at 1073, 1273, 1473, and 1573 K, as well as a vertical section of the Ti3Al?Ti + 5 wt.% Zr were used to assess this system. The thermodynamic parameters of the binary Ti?Al, Al?Zr and Ti?Zr systems were acquired from recent assessments, and the ternary ones were evaluated in the present work. The Ti?Al?Zr ternary dataset has been established and the calculated results are in close agreement with the experimental data on both thermodynamics and phase equilibria.

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