Article
Chemistry, Physical
Mikhail Petrik, Ilya Razumov, Yuri Gornostyrev, Inna Naschetnikova, Artemyi Popov
Summary: The ordering and decomposition processes in Ti-Al-X alloys were investigated using Monte Carlo simulations with first-principles parametrization. It was found that the stage of homogeneous ordering precedes the formation of ordered Ti3Al particles, and the duration of homogeneous ordering is sensitive to the annealing temperature and alloy composition.
Article
Physics, Applied
Shuo Huang, Jie Cheng, Lei Liu, Wei Li, Hongyun Jin, Levente Vitos
Summary: This work investigates the thermo-elastic properties of a group of rare-earth-free high-entropy alloys with hcp structures. It is found that these alloys exhibit high elastic isotropy and large elastic softening resistance. The calculated results are in good agreement with experimental measurements.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Xi Zhang, Sergiy Divinski, Blazej Grabowski
Summary: In this study, ab initio density-functional-theory calculations were used to investigate the vacancy formation and migration energies in HCP Al-Hf-Sc-Ti-Zr high entropy alloys (HEAs) and their subsystems. The temperature-dependent formation Gibbs energies and averaged atomic environments were obtained using the special quasi-random structure approach and statistical analysis. It was found that the temperature-dependent vacancy formation Gibbs energy had a negative configurational entropy contribution. The local cluster expansion technique was applied to explore extended vacancy migration phase spaces.
Article
Materials Science, Multidisciplinary
Dayong Wu, Sida Ma, Tao Jing, Yandong Wang, Lisheng Wang, Jie Kang, Qian Wang, Wei Wang, Tian Li, Ru Su
Summary: The study developed a new master alloy with excellent grain refinement performance by incorporating titanium into an aluminum-niobium-boron alloy. Through analysis of interfacial energy, silicon adsorption, and alpha-Al nucleation, the research revealed the mechanism behind the anti Si-poisoning ability of the alloy.
Article
Nanoscience & Nanotechnology
C. B. Basak, A. K. Poswal
Summary: The Gibbs free energy expression in the Ti-Zr system's alpha-solid solution indicates the presence of a miscibility gap. Thermal aging and observation of phase separation are hindered by unfavorable kinetics. The non-random solid solution structure suggests the existence of a miscibility gap.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Angeliki Poulou, Thomas A. Mellan, Michael W. Finnis
Summary: The study calculated the stability of Zr and Ti-based MAX phases at different temperatures using density functional theory, finding that Zr-based MAX phases decompose below room temperature, while Ti2AlC phase is stable at room temperature.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Biochemistry & Molecular Biology
Jean-Francois Gal, Pierre-Charles Maria, Manuel Yanez, Otilia Mo
Summary: The study examined the Lewis basicity of organic bases by modeling the enthalpies of adduct formation between gaseous BF3 and bases in DCM solution. Results showed that DCM played an important role as a solvent, influencing the enthalpy values of the reaction, with specific solvation being a key factor.
Article
Chemistry, Physical
Junjie Shi, Cameron J. Owen, Hio Tong Ngan, Siyu Qin, Vikram Mehar, Philippe Sautet, Jason F. Weaver
Summary: A single atom Ti-Cu(111) surface alloy can be generated by depositing small amounts of Ti onto Cu(111) at slightly elevated surface temperatures. Different structures of Ti are formed on the Cu(111) surface at different temperatures, and CO adsorbs differently on the single atom Ti-Cu(111) surface alloy and Cu-covered Ti-containing domains.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Lu Wu, Vasyl O. Kharchenko, Dmitrii O. Kharchenko, Rongjian Pan
Summary: The structural and energetic properties of Zr-Sn, Zr-Nb, and Nb-Sn binary alloys were studied using density functional theory, analyzing the behavior of different alloying additions in a host matrix and discussing the stability of various phases with different concentrations of alloying elements. The binding vacancy-impurity energy was calculated, and the ability of different impurities to trap single vacancies in different alloys was discussed in detail.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Michael Musi, Stefan Kardos, Lukas Hatzenbichler, David Holec, Andreas Stark, Melissa Allen, Volker Guther, Helmut Clemens, Petra Spoerk-Erdely
Summary: In recent years, Zr has emerged as a promising alloying element for intermetallic gamma-TiAl based alloys to improve their mechanical properties. This study focuses on the influence of Zr on the microstructure and thermodynamic phase equilibria in the ternary Ti-(42-46)Al-(2-4)Zr (at.%) system. The results show that alloying with Zr increases the amount of the gamma phase and enhances the hardness of the material. Additionally, the high Zr alloyed materials exhibit a decrease in solidus temperature. These findings are important for understanding and optimizing the performance of gamma-TiAl based alloys.
Article
Chemistry, Physical
Gloria Graf, Malina Seyffertitz, Petra Spoerk-Erdely, Helmut Clemens, Andreas Stark, Lukas Hatzenbichler, David Holec, Michael Burtscher, Daniel Kiener, Xiaobing Li, Kui Liu
Summary: In order to promote the use of intermetallic γ-TiAl based alloys in the aircraft and automotive sector, recent research has focused on the development of low-cost titanium aluminides. The addition of manganese has shown potential to replace more expensive alloying elements and improve the ductility. However, Mn-containing alloys are prone to the formation of undesired brittle phases, which can affect the ductility. This study investigated the transformation kinetics and stability range of a specific brittle phase in a low-cost Ti-42Al-5Mn alloy using experimental and computational approaches. The results provide valuable insights for the future design of low-cost γ-TiAl based alloys.
Article
Crystallography
J. M. Ramirez-de-Arellano, A. Fransuani Jimenez G., L. F. Magana
Summary: The study found that doping a hexagonal boron nitride surface with Ti or Pt can influence the adsorption of CO2 molecules in different ways. Titanium atoms allow for the chemisorption of CO2 molecules, while platinum atoms result in the repulsion of CO2 molecules.
Article
Biochemistry & Molecular Biology
Egor Kashkarov, Dmitriy Krotkevich, Maxim Koptsev, Sergei Ognev, Leonid Svyatkin, Nahum Travitzky, Andrey Lider
Summary: This study investigated the application of high-entropy alloys in hydrogen separation membranes, revealing the influence of different compositions and lattice structures on hydrogen localization and diffusivity. A comparison of hydrogen permeability among different alloys was also conducted.
Article
Materials Science, Multidisciplinary
Par A. T. Olsson
Summary: In this study, we performed ab initio calculations to investigate the thermo-elastic properties of delta-MH1.5 (M=Zr, Ti). Our results reveal the anisotropic temperature dependence of elastic constants in hydrides and address discrepancies in thermal expansion data found in the literature. The findings provide important input for phase-transformation modelling based on thermodynamics. By considering the reduced contribution from vibrational free energy, we confirmed the experimental observations that the stiffness of hydrides varies less than the matrix. Additionally, we observed a temperature-dependent variation in Zener's anisotropy ratio for delta-ZrH1.5.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Oliver G. Nicholls, Dillion G. Frost, Vidur Tuli, Jana Smutna, Mark R. Wenman, Patrick A. Burr
Summary: Tens of Zr potentials were compared for the simulations of Zr alloys, and their ability to reproduce key properties was assessed. No potential outperformed all others, but at least one potential provided reliable results for each metric considered. The two highest-performing potentials were the 2021 angular-dependent potential of Smirnova and Starikov and the 2019 embedded-atom method potential of Wimmer et al. Machine learning potentials had lower overall accuracy and transferability. Point defect structures and energies showed the greatest divergence and least accuracy. Maps were created to help select suitable potentials and identify areas of improvement. © 2023 Elsevier B.V. All rights reserved.
JOURNAL OF NUCLEAR MATERIALS
(2023)
