A series of Ti2ZrHf0.5VNbx (x = 0, 0.25, 0.5, 0.75 and 1.0) refractory high-entropy alloys were prepared to investigate the alloying effect of Nb on the microstructures and mechanical properties. All the alloys displayed a simple BCC structure. The microstructures of the alloys changed from the initial single-phase columnar structure (x = 0) to dendrite microstructure (x > 0). At room temperature, all the alloys exhibited high ductility (with the compressive strains of more than 50%). With the increase in Nb content, the yield strength slightly decreased from 1160 to 980 MPa and the hardness dropped from 338 to 310 HV. Moreover, the alloys exhibited low density from 6.47 to 6.84 g/cm3 and high specific yield strength (SYS) from 143 to 179 kPa m3/kg. The comprehensive performance of ductility and SYS was superior to most of the reported high-entropy alloys. The yield strength of the alloys increased from 405 to 859 MPa and from 85 to 195 MPa with the addition of Nb element at 873 K and 1073 K, respectively.
Abstract A serrated flow, which occurs in a material undergoing mechanical deformation, is a complex process of great engineering significance. Here statistical, dynamical, and multifractal modeling and analyses were performed on the stress-time series to characterize and model the stress-drop behavior of an Al0.5CoCrCuFeNi high-entropy alloy (HEA). Results indicate that the spatiotemporal dynamics of the serrated flow is affected by changes in the strain rate and test temperature. The sample en...
#1Yan-cai Liu(CUMT: China University of Mining and Technology)H-Index: 2
#2Zhanqing Chen(CUMT: China University of Mining and Technology)H-Index: 3
Last. Zhang Jinyao(CUMT: China University of Mining and Technology)H-Index: 5
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Abstract The multicomponent AlxCoCrCuFeNi high entropy alloys (x = 0, 0.5, 1, 1.5, 2) were prepared by vacuum arc melting. The relation of Al content, microstructures, mechanical properties and electrochemical properties was investigated by XRD, SEM, TEM, hardness and electrochemical tests. Three typical structures including Cu-rich nano-precipitates of FCC structure, Al Ni-rich plate of B2 structure, and Fe Cr-rich plate of BCC structure were observed in the refined microstructures with the inc...
Last. Jia-Kang Yu(NPU: Northwestern Polytechnical University)H-Index: 2
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The corrosion behavior of CoCrFeNiMox alloys was investigated in aqueous environments, NaCl and H2SO4 solutions, respectively, to simulate typical neutral and acidic conditions. The cyclic polarization curves in NaCl and the potentiodynamic curves in H2SO4 clearly reveal the beneficial effects of Mo and the detrimental effect of σ-phase on the corrosion resistance. The X-ray photoelectron spectroscopy results of CoCrFeNiMox alloys in H2SO4 solution indicate that Cr and Mo predominate the corrode...
#1Yiping Lu(DUT: Dalian University of Technology)H-Index: 30
#2Hefei Huang(CAS: Chinese Academy of Sciences)H-Index: 14
Last. Tingju Li(DUT: Dalian University of Technology)H-Index: 26
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Abstract Recently, high-entropy alloys (HEAs) or multi-principal-element alloys with unprecedented physical, chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their promising irradiation resistant behavior. Here, we report a new single-phase body-centered cubic (BCC) structured Ti 2 ZrHfV 0.5 Mo 0.2 HEA possessing excellent irradiation resistance, i.e., scarcely irradiation hardening and abnormal lattice constant reduction after hel...
#1Chanho Lee(UT: University of Tennessee)H-Index: 12
#2Gian Song(KNU: Kongju National University)H-Index: 16
Last. Peter K. Liaw(UT: University of Tennessee)H-Index: 94
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Abstract The maximization of the mixing entropy with the optimal range of enthalpy in high-entropy alloys (HEAs) can promote the formation of a stable single solid-solution phase with the absence of competing intermetallic compounds. The resultant effects, such as lattice distortion, can contribute to excellent mechanical properties, which has motivated numerous efforts to develop and design single-phase HEAs. However, challenges still remain, particularly on quantifying the lattice distortion a...
Last. Peter K. Liaw(UT: University of Tennessee)H-Index: 94
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Abstract Nanoindentation tests were performed to investigate the nano-scale plastic deformation in the Al0.5CoCrCuFeNi high entropy alloys at room temperature (RT) and 200 °C, respectively. Serrated plastic flow, manifested as discrete bursts of plasticity on the load-displacement curves, was observed for both temperatures during the loading period, and its behavior and dependence on the temperature was analyzed from the experimental perspective. Creep occurred during the nanoindentation holding...
#1Shao-Ping Wang(CAS: Chinese Academy of Sciences)H-Index: 3
#2Jian Xu(CAS: Chinese Academy of Sciences)H-Index: 34
In this work, the evolution of microstructure and fundamental mechanical properties with Mo concentration in the arc-melted (TiZrNbTa)(100-x)Mo-x (0 <= x <= 20) high-entropy alloys (HEAs) are investigated. The arc-melted (TiZrNbTa)(100-x)Mo-x alloys structurally consist of two bcc phases. The change in volume fractions of two phases in the microstructure is insignificant with Mo concentration, at levels of similar to 75% for bcc1 and similar to 25% for bcc2. The increases in microhardness and Yo...
Abstract Structure and mechanical properties of the AlNbTiVZr x (x = 0; 0.1; 0.25; 0.5; 1; 1.5) refractory high-entropy alloys were investigated after arc melting and annealing at 1200 °C for 24 h. The AlNbTiV alloy had a B2 ordered single phase structure. Alloying with Zr resulted in (i) change of the degree of order of the B2 phase; and (ii) precipitation of the Zr 5 Al 3 and C14 Laves ZrAlV phases. The density of the AlNbTiVZr x alloys varied from 5590 kg m −3 for the AlNbTiV alloy to 5870 kg...
#1Jiang Hui(DUT: Dalian University of Technology)H-Index: 1
#2Jiang Li(DUT: Dalian University of Technology)H-Index: 3
Last. Ting-ju Li(DUT: Dalian University of Technology)H-Index: 11
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A series of CoCrFeNb x Ni ( x values in molar ratio, x = 0, 0.25, 0.45, 0.5, 0.75, 1.0 and 1.2) high entropy alloys (HEAs) was prepared to investigate the alloying effect of Nb on the microstructures and mechanical properties. The results indicate that the prepared CoCrFeNb x Ni ( x > 0) HEAs consist of a simple FCC solid solution phase and a Laves phase. The microstructures of the alloys change from an initial single-phase FCC solid solution structure ( x = 0) to a hypoeutectic microstructure (...
Abstract Serrated flow in Al 0.5 CoCrFeNi high entropy alloy (HEA) was studied at the temperature range of 200–500 °C with strain rates from 10 −3 s −1 to 10 −4 s −1 . Results showed that serration type would transform from type A to type A+B, and eventually evolved into type B+C with the increasing temperature and decreasing strain rate. The dynamic strain aging was the reason for the Portevin-Le Chatelier (PLC) effect, and Al played a crucial role in the interaction between solute atoms and di...
#1Hui Liang(DUT: Dalian University of Technology)H-Index: 3
#2Dongxu Qiao(DUT: Dalian University of Technology)H-Index: 6
Last. Tongmin Wang(DUT: Dalian University of Technology)H-Index: 34
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Abstract To evaluate the potential of high entropy alloys for marine applications, a new high entropy alloy coating of AlCrFeNiW0.2Ti0.5 was designed and produced on Q235 steel via laser cladding. The microstructure, microhardness and tribological performances sliding against YG6 cemented carbide, GCr15 steel and Si3N4 ceramic in seawater were studied in detail. The AlCrFeNiW0.2Ti0.5 coating showed an anomalous ‘sunflower-like’ morphology and consisted of BCC and ordered B2 phases. The microhard...
Abstract NbMoTaW refractory high entropy alloy (RHEA) possesses superior high temperature mechanical strength while the very low plastic strain at room temperature limits its practical applications. In present work, the method of adjusting composition was employed to improve the mechanical properties of (NbTaW)1-xMox (x=0, 0.05, 0.15, 0.25) alloys especially the plasticity at room temperature by the combination of experiments and first-principles calculations. Phase composition of the (NbTaW)1-x...
#1Dongxu Qiao(DUT: Dalian University of Technology)H-Index: 6
#2Hui Liang(DUT: Dalian University of Technology)H-Index: 3
Last. Tingju Li(DUT: Dalian University of Technology)H-Index: 26
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Abstract null null A series of novel B2-ordered Ti2ZrHf0.5VNb0.5Alx refractory high-entropy alloys (RHEAs) was designed and prepared by vacuum arc-melting. The effect of Al alloying on the microstructure, mechanical properties, and oxidation properties was investigated. The Al addition triggers the transformation of the crystal structure from disordered BCC phase to ordered B2 phase, and the Al1 alloy present single B2 phase structure. This B2 ordering results in significant yield strength incre...
#1Lijuan Xu(HIT: Harbin Institute of Technology)H-Index: 14
#2Zhaoqi Chen(HIT: Harbin Institute of Technology)
Last. Yuyong Chen(HIT: Harbin Institute of Technology)H-Index: 23
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Abstract null null A high entropy alloy (HEA) with a composition of Ti2ZrMo0.5Nb0.5 was prepared by vacuum induction melting technology. The mechanical properties at room temperature and elevated temperature (900 °C–1150 °C), microstructure evolution and hot deformation behavior during hot deformation are studied. The as-cast alloy is composed of equiaxed grains with the yield strength, the apparent plastic strain of 1306 MPa and 44%, respectively. By TEM analysis, the ZrTi2 Laves C15 phase is f...
Abstract This study aimed to develop a novel series of low-density refractory high-entropy alloys (RHEAs) by precipitation strengthening. The design ideas of high-entropy alloys and titanium alloys were combined to develop Ti3V2NbAl0.5, Ti3V2NbNi0.5, and Ti3V2NbAl0.5Ni0.5 refractory multielement alloys. These alloys displayed low densities of 5.39, 5.83, and 5.55 g/cm3, respectively. The effects of Al and Ni addition on the microstructure and mechanical properties were investigated. Thereinto, t...
In the present study, we investigate the crystal structure of high-entropy alloys (HEAs) in the form of CoFe2NiMn0.3AlCux (x = 0.25, 0.50, 0.75, and 1.00) and their mechanical and magnetic properties. The CoFe2NiMn0.3AlCux alloys are composed of a mixture of a body-centered cubic (BCC) and a face-centered cubic (FCC) solid solution. The increased amounts of copper (Cu) boost both alloy strength and plastic ductility. The CoFe2NiMn0.3AlCu1.0 HEAs demonstrate excellent mechanical properties, such ...
Last. Bi-Yu Tang(Xida: Guangxi University)H-Index: 23
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On basis of systematical ab initio study of mechanical properties of body-centered cubic NbTiZrM (M = Hf, Ta, W) refractory high entropy alloys, the correlation between mechanical properties and valence electron concentration (VEC) is appreciably revealed. The present investigation demonstrates that both the single-crystal elastic parameters and the elastic moduli of NbTiZrM alloys increase for M from Hf to W, similar to the variation trend of VEC. Hence, the strength and hardness of NbTiZrM all...
Hardness is an essential property in the design of refractory high entropy alloys (RHEAs). This study shows how a neural network (NN) model can be used to predict the hardness of a RHEA, for the first time. We predicted the hardness of several alloys, including the novel C0.1Cr3Mo11.9Nb20Re15Ta30W20 using the NN model. The hardness predicted from the NN model was consistent with the available experimental results. The NN model prediction of C0.1Cr3Mo11.9Nb20Re15Ta30W20 was verified by experiment...
