Influence of sequence of elemental addition on phase evolution in nanocrystalline AlCoCrFeNi: Novel approach to alloy synthesis using mechanical alloying

Vaidya, M.; Prasad, Anil; Parakh, Abhinav; Murty, B.S.

doi:10.1016/j.matdes.2017.04.027

Cited by 82 publications

(26 citation statements)

References 23 publications

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“…1b) confirmed the HH phase formation crystallizing in the F 3m symmetry. The fraction of Sn phase was calculated through Relative Intensity Ratio (RIR) analysis 26 to be 8%. The (020) peak of Sn phase and (220) peak of HH phase for analysis.…”

Section: Resultsmentioning

confidence: 99%

Ti2NiCoSnSb - a new half-Heusler type high-entropy alloy showing simultaneous increase in Seebeck coefficient and electrical conductivity for thermoelectric applications

Karati

Nagini

Ghosh

et al. 2019

Sci Rep

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A new single phase high entropy alloy, Ti 2 NiCoSnSb with half-Heusler (HH) structure is synthesized for the first time by vacuum arc melting (VAM) followed by ball-milling (BM). The BM step is necessary to obtain the single phase. Local electrode atom probe (LEAP) analysis showed that the elements are homogeneously and randomly distributed in the HH phase without any clustering tendency. When the BM was carried out for 1 hour on the VAM alloy, microcrystalline alloy is obtained with traces of Sn as secondary phase. When BM was carried out for 5 h, single HH phase formation is realized in nanocrystalline form. However, when the BM samples were subjected to Spark plasma sintering (SPS), secondary phases were formed by the decomposition of primary phase. Nanostructuring leads to simultaneous increase in S and σ with increasing temperature. The micro (1 h BM-SPS) and nanocrystalline (5 h BM-SPS) alloys exhibited a power factor (S 2 σ) of 0.57 and 1.02 mWm −1 K −2 , respectively, at 860 K. The microcrystalline sample had a total thermal conductivity similar to bulk TiNiSn sample. The nanocrystalline alloy exhibited a ZT of 0.047 at 860 K. The microcrystalline alloy showed a ZT to 0.144 at 860 K, in comparison to the nanocrystalline alloy.

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Section: Resultsmentioning

confidence: 99%

Ti2NiCoSnSb - a new half-Heusler type high-entropy alloy showing simultaneous increase in Seebeck coefficient and electrical conductivity for thermoelectric applications

Karati

Nagini

Ghosh

et al. 2019

Sci Rep

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“…Several investigations concern MA only. For instance, Vaidya et al studied the influence of the sequential addition of elements during milling in Mechanical Alloying [16].…”

Section: Introductionmentioning

confidence: 99%

Effects of planetary ball milling on AlCoCrFeNi high entropy alloys prepared by Spark Plasma Sintering: Experiments and molecular dynamics study

Fourmont

Gallet

Politano

et al. 2020

Journal of Alloys and Compounds

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The elaboration of High Entropy Alloys (HEA) was investigated by means of powder metallurgy. We studied the combination of mechanical activation and reactive sintering in the case of AlCoCrFeNi. Elemental metallic powders were first processed by planetary ball milling over a long duration (28 h). The ratio K between the rotating speed of the sun wheel and the relative rotating speed of the grinding vials was set at 0.2 and 1 corresponding to "medium" energy milling. Given the particular hardness of chromium as compared to other elements, the effect of Cr powder size was investigated and optimized. In addition to experimental characterizations of milled powders, Molecular Dynamics simulations were carried out in order to assess the formation of solid solutions. The activated powders were then consolidated by Spark Plasma Sintering at 1000 °C and 1100 °C. A nanostructured lamellar microstructure exhibiting the coexistence of the FCC and BCC phases was synthesized by this solid-state route. The sintered materials exhibited hardness of up to 670 HV. Our final results (i.e., after optimization of the milling and sintering parameters) suggest that mechanical activation combined with reactive sintering is an efficient route to elaborate dense HEA materials.

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“…This is due to the similar lattice parameter between AlNi (0.28810 nm) and AlCoCrFeNi (0.289675 nm) [ 77 , 78 ]. In addition, AlNi has the largest negative enthalpy of formation among all the binary pairs in AlCoCrFeNi [ 79 , 80 , 81 ]. The AlNi binary pair stabilizes over a wide composition field from 1638 °C down to room temperature and can dissolve other constituent elements [ 82 , 83 ].…”

Section: Microstructural Evolution Of Heas Synthesized Through the Melting And Casting Routementioning

confidence: 99%

Synthesis Route, Microstructural Evolution, and Mechanical Property Relationship of High-Entropy Alloys (HEAs): A Review

et al. 2021

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Microstructural phase evolution during melting and casting depends on the rate of cooling, the collective mobility of constituent elements, and binary constituent pairs. Parameters used in mechanical alloying and spark plasma sintering, the initial structure of binary alloy pairs, are some of the factors that influence phase evolution in powder-metallurgy-produced HEAs. Factors such as powder flowability, laser power, powder thickness and shape, scan spacing, and volumetric energy density (VED) all play important roles in determining the resulting microstructure in additive manufacturing technology. Large lattice distortion could hinder dislocation motion in HEAs, and this could influence the microstructure, especially at high temperatures, leading to improved mechanical properties in some HEAs. Mechanical properties of some HEAs can be influenced through solid solution hardening, precipitation hardening, grain boundary strengthening, and dislocation hardening. Despite the HEA system showing reliable potential engineering properties if commercialized, there is a need to examine the effects that processing routes have on the microstructure in relation to mechanical properties. This review discusses these effects as well as other factors involved.

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Influence of sequence of elemental addition on phase evolution in nanocrystalline AlCoCrFeNi: Novel approach to alloy synthesis using mechanical alloying

Cited by 82 publications

References 23 publications

Ti2NiCoSnSb - a new half-Heusler type high-entropy alloy showing simultaneous increase in Seebeck coefficient and electrical conductivity for thermoelectric applications

Ti2NiCoSnSb - a new half-Heusler type high-entropy alloy showing simultaneous increase in Seebeck coefficient and electrical conductivity for thermoelectric applications

Effects of planetary ball milling on AlCoCrFeNi high entropy alloys prepared by Spark Plasma Sintering: Experiments and molecular dynamics study

Synthesis Route, Microstructural Evolution, and Mechanical Property Relationship of High-Entropy Alloys (HEAs): A Review

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