scholarly journals How 10 at% Al Addition in the Ti-V-Zr-Nb High-Entropy Alloy Changes Hydrogen Sorption Properties

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2470
Author(s):  
Jorge Montero ◽  
Gustav Ek ◽  
Laetitia Laversenne ◽  
Vivian Nassif ◽  
Martin Sahlberg ◽  
...  

Al0.10Ti0.30V0.25Zr0.10Nb0.25 was prepared to evaluate the effect of 10% aluminum into the previously reported quaternary alloy, Ti0.325V0.275Zr0.125Nb0.275. The as-cast quinary alloy formed a single-phase body centered cubic solid solution and transformed into a body centered tetragonal after hydrogenation. The alloy had a storage capacity of 1.6 H/M (2.6 wt.%) with fast absorption kinetics at room temperature, reaching full capacity within the first 10 min. The major improvements of Al addition (10%) were related to the desorption and cycling properties of the material. The temperature for hydrogen release was significantly decreased by around 100 °C, and the quinary alloy showed superior cycling stability and higher reversible storage capacity than its quaternary counterpart, 94% and 85% of their respective initial capacity, after 20 hydrogenation cycles without phase decomposition.

Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.


2014 ◽  
Vol 62 ◽  
pp. 105-113 ◽  
Author(s):  
J.Y. He ◽  
W.H. Liu ◽  
H. Wang ◽  
Y. Wu ◽  
X.J. Liu ◽  
...  

2021 ◽  
pp. 161579
Author(s):  
Reliance Jain ◽  
M.R. Rahul ◽  
Poulami Chakraborty ◽  
Rama Krushna Sabat ◽  
Sumanta Samal ◽  
...  

2018 ◽  
Vol 160 ◽  
pp. 1208-1216 ◽  
Author(s):  
B. Kombaiah ◽  
K. Jin ◽  
H. Bei ◽  
P.D. Edmondson ◽  
Y. Zhang

2018 ◽  
Vol 98 ◽  
pp. 79-88 ◽  
Author(s):  
J.Q. Yao ◽  
X.W. Liu ◽  
N. Gao ◽  
Q.H. Jiang ◽  
N. Li ◽  
...  

2021 ◽  
Vol 1035 ◽  
pp. 46-50
Author(s):  
Lei Gang Cao ◽  
Peng Yu Hou ◽  
Ahmed Nassar ◽  
Andrew M. Mullis

Mould casting and drop-tube techniques were used to solidify a AlCoCrFeNi2.1 eutectic high-entropy alloy under conditions of high cooling rate. The samples obtained from two different methods present the same phase constituent, FCC and B2 phases. During mould casting experiments the alloy almost solidified into the eutectic structure consisting of lamellar and anomalous morphology, with a tiny fraction of cellular and dendrite morphology being observed at certain sites of the sample surface due to the corresponding high cooling rate. Instead, during drop-tube experiments a typical, coarse dendrite structure of FCC single phase was formed across the entire 106-150 μm particle. The cellular structure can also be formed directly from the melt. The rest region solidified into the general eutectic morphology as was observed in the casting rods. The results clearly indicate the transition from coupled eutectic growth to single-phase dendrite growth with increasing departures from equilibrium for the multi-component AlCoCrFeNi2.1 eutectic high-entropy alloy.


2021 ◽  
Author(s):  
J. Shi ◽  
Y.W. Zhao ◽  
Chunli Jiang ◽  
Y.Z. Zhang ◽  
Dongli Zou ◽  
...  

2018 ◽  
Vol 152 ◽  
pp. 40-43 ◽  
Author(s):  
M. Feuerbacher ◽  
T. Lienig ◽  
C. Thomas

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1020 ◽  
Author(s):  
Bhupendra Sharma ◽  
Kentaro Nagano ◽  
Kuldeep Kumar Saxena ◽  
Hiroshi Fujiwara ◽  
Kei Ameyama

For the first time, an equiatomic refractory high entropy alloy (RHEA) TiNbZrHfTa compact with a single-phase body-centered cubic (BCC) structure was fabricated via a titanium hydride (TiH2) assisted powder metallurgy approach. The constituent pure Ti, Zr, Nb, Hf, and Ta powders were mechanically alloyed (MA) with titanium hydride (TiH2) powder. The resultant MA powder was dehydrogenated at 1073 K for 3.6 ks and subsequently sintered through spark plasma sintering (SPS). Additionally, TiNbZrHfTa counterparts were prepared from pure elements without MA with TiH2. It was observed that the compact prepared from pure powders had a chemically heterogeneous microstructure with hexagonal close packed (HCP) and dual BCC phases. On the other hand, despite containing many constituents, the compact fabricated at 1473 K for 3.6 ks via the hydride approach had a single-phase BCC structure. The Vickers microhardness of the TiNbZrHfTa alloy prepared via the hydride process was Hv 520 (±30). The exceptional microhardness of the alloy is greater than any individual constituent, suggesting the operation of a simple solid-solution-like strengthening mechanism and/or precipitation hardening. In addition, the heat treatments were also carried out to analyze the phase stability of TiNbZrHfTa prepared via the hydride process. The results highlight the substantial changes in the phase as a function of temperature and/or time.


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