Phase Decomposition and Strengthening in Hfnbtatizr High Entropy Alloy from First-Principles Calculations

2021 ◽  
Author(s):  
Shu-ming Chen ◽  
Ze-Jun Ma ◽  
Shi Qiu ◽  
Lian-Ji Zhang ◽  
Shang-Zhou Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
High Entropy Alloy ◽  
Phase Decomposition ◽  
First Principles Calculations ◽  
High Entropy

Phase decomposition and strengthening in HfNbTaTiZr high entropy alloy from first-principles calculations

2021 ◽  
pp. 117582
Author(s):  
Shu-Ming Chen ◽  
Ze-Jun Ma ◽  
Shi Qiu ◽  
Lian-Ji Zhang ◽  
Shang-Zhou Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
High Entropy Alloy ◽  
Phase Decomposition ◽  
First Principles Calculations ◽  
High Entropy

scholarly journals An investigation of high entropy alloy conductivity using first-principles calculations

2021 ◽  
Vol 119 (12) ◽  
pp. 121903
Author(s):  
Vishnu Raghuraman ◽  
Yang Wang ◽  
Michael Widom
Keyword(s):  
First Principles ◽  
High Entropy Alloy ◽  
First Principles Calculations ◽  
High Entropy

scholarly journals Elemental Phase Partitioning in the γ-γ″ Ni2CoFeCrNb0.15 High Entropy Alloy

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 910 ◽  
Author(s):  
Bin Han ◽  
Jie Wei ◽  
Feng He ◽  
Da Chen ◽  
Zhi Wang ◽  
...  
Keyword(s):  
First Principles ◽  
Atom Probe Tomography ◽  
Atom Probe ◽  
Alloying Elements ◽  
High Entropy Alloy ◽  
First Principles Calculations ◽  
Specific Chemical ◽  
High Entropy ◽  
Phase Partitioning ◽  
Chemical Potentials

The partitioning of the alloying elements into the γ″ nanoparticles in a Ni2CoFeCrNb0.15 high entropy alloy was studied by the combination of atom probe tomography and first-principles calculations. The atom probe tomography results show that the Co, Fe, and Cr atoms incorporated into the Ni3Nb-type γ″ nanoparticles but their partitioning behaviors are significantly different. The Co element is much easier to partition into the γ″ nanoparticles than Fe and Cr elements. The first-principles calculations demonstrated that the different partitioning behaviors of Co, Fe and Cr elements into the γ″ nanoparticles resulted from the differences of their specific chemical potentials and bonding states in the γ″ phase.

scholarly journals Effect of Ti Content on the Microstructure and Corrosion Resistance of CoCrFeNiTix High Entropy Alloys Prepared by Laser Cladding

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2209 ◽  
Author(s):  
Xinyang Wang ◽  
Qian Liu ◽  
Yanbin Huang ◽  
Lu Xie ◽  
Quan Xu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Laser Cladding ◽  
First Principles ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
First Principles Calculations ◽  
High Entropy ◽  
Niti Phase ◽  
Fcc Phase ◽  
Ti Content

In this paper, CoCrFeNiTix high entropy alloy (HEA) coatings were prepared on the surface of Q235 steel by laser cladding. The microstructure, microhardness, and corrosion resistance of the coatings were studied. The mechanism of their corrosion resistance was elucidated experimentally and by first-principles calculations. The results show that CoCrFeNiTi0.1 adopts a face-centered cubic (FCC) phase, CoCrFeNiTi0.3 exhibits an FCC phase and a tetragonal FeCr phase, and CoCrFeNiTi0.5 adopts an FCC phase, a tetragonal FeCr phase, and a rhombohedral NiTi phase. The FCC phase, tetragonal FeCr phase, rhombohedral NiTi phase, and hexagonal CoTi phase are all observed in the CoCrFeNiTi0.7 HEA. The alloys assume the dendritic structure that is typical of HEAs. Ni and Ti are enriched in the interdendritic regions, whereas Cr and Fe are enriched in the dendrites. With increasing Ti content, the hardness of the cladding layers also increases due to the combined effects of lattice distortion and dispersion strengthening. When exposed to a 3.5 wt.% NaCl solution, pitting corrosion is the main form of corrosion on the CoCrFeNiTix HEA surfaces. The corrosion current densities of CoCrFeNiTix HEAs are much lower than those of other HEAs. As the Ti content increases, the corrosion resistance is improved. Through X-ray photoelectron spectroscopy (XPS) and first-principles calculations, the origin of the higher corrosion resistance of the coatings is connected to the presence of a dense passivation film. In summary, the corrosion resistance and mechanical properties of CoCrFeNiTi0.5 alloy are much better than the other three groups, which promotes the development of HEA systems with high value for industrial application.

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