Recent developments of high-entropy alloys with high strength and high ductility draw attention to the metastability-engineering strategy. Using first-principle theory, here we demonstrate that reducing the Ta level in the refractory TiZrHfTa system destabilizes the body-centered cubic (bcc) phase and leads to the appearance of the hexagonal close-packed (hcp) phase embedded in the bcc matrix. The alloying-induced features of the elastic parameters for the cubic and hexagonal structures are mapped out in details, and strong sensitivity to the crystal lattice and chemistry is revealed. Results show softening of the bcc matrix with decreasing Ta concentration which ensures ductile behavior. However, the elastically nearly isotropic hcp precipitates possess enhanced resistance against shear which promotes strengthening of the TiZrHfTa dual-phase system. The present atomic-level insight provides strong evidence to the experimental observation, and emphasizes the significance of quantum-design for advanced multi-phase high-entropy alloys with excellent strength-ductility combinations.
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http://dx.doi.org/10.1038/s41598-018-30892-x | DOI Listing |
J Am Chem Soc
January 2025
Department of Physical Chemistry, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Lattice distortion and disorder in the chemical environment of magnetic atoms within high-entropy compounds present intriguing issues in the modulation of magnetic functional compounds. However, the complexity inherent in high-entropy disordered systems has resulted in a relative scarcity of comprehensive investigations exploring the magnetic functional mechanisms of these alloys. Herein, we investigate the magnetocaloric effect (MCE) of the high-entropy intermetallic compound GdTbDyHoErCo.
View Article and Find Full Text PDFThis study examines the intricate area of refractory-based high entropy alloys (RHEAs), focusing on a series of complex compositions involving nine diverse refractory elements: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W. We investigate the phase stability, bonding interactions, electronic structures, lattice distortions, mechanical, and thermal properties of six RHEAs with varying elemental ratios using VASP and OLCAO DFT calculations. Through comprehensive analysis, we investigate the impact of elemental variations on the electronic structure, interacting bond dynamics, lattice distortion, thermodynamic, mechanical, and thermal properties within these RHEAs, providing an insight into how these specific elemental variations in composition give rise to changes in the calculated properties in ways that would guide future experimental and computational efforts.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Faculty of Materials Science and Chemistry, China University of Geosciences Wuhan, 388 Lumo RD, Wuhan, 430074, China.
FeCoNiIrPtPd/NCNT exhibits 3.4- and 1.6-fold higher levels of mass activity than does commercial Pt/C in the hydrogen evolution reaction (HER) and ethanol oxidation reaction (EOR), respectively.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China.
Next-generation advanced high/pulsed power capacitors rely heavily on dielectric ceramics with high energy storage performance. Although high entropy relaxor ferroelectric exhibited enormous potential in functional materials, the chemical short-range order, which is a common phenomenon in high entropy alloys to modulate performances, have been paid less attention here. We design a chemical short-range order strategy to modulate polarization response under external electric field and achieve substantial enhancements of energy storage properties, i.
View Article and Find Full Text PDFACS Nano
January 2025
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan 250061, P. R. China.
To achieve a long cycle life and high-capacity performance for Li-O batteries, it is critical to rationally modulate the formation and decomposition pathway of the discharge product LiO. Herein, we designed a highly efficient catalyst containing dual catalytic active sites of Pt single atoms (Pt) paired with high-entropy alloy (HEA) nanoparticles for oxygen reduction reaction (ORR) in Li-O batteries. HEA is designed with a moderate d-band center to enhance the surface adsorbed LiO intermediate (LiO(ads)), while Pt active sites exhibit weak adsorption energy and promote the soluble LiO pathway (LiO(sol)).
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