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Characteristics of atomic pairs in ferrous bulk metallic glasses (BMGs) have statistically been analyzed using digitized data on mixing enthalpy (∆ ) based on the Miedema's model and local atomic arrangements for binary compounds listed in Pettifor map. The main element of the ternary ferrous BMGs tend to be the element with intermediate atomic rad...
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... wide applicability of data for the elements of the BMG formers. For comparison, the atomic size mismatch (∆r) is tabulated in upper-right side of Table 2, although it is not directly discussed in the present study. The ∆r is calculated with ∆r = |2 . (r a -r b )/(r a +r b )|, where r a and r b denote atomic radius of A and B atoms, respectively. Fig. 2 shows characteristics of BMGs with respects to atomic size mismatch and . Figure 2 is drawn on the previous result [4], and is in particular emphasized for the ferrous BMGs. In Fig. 2 (a), atomic radii of elements are plotted in sequence from the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the ...
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... 2 shows characteristics of BMGs with respects to atomic size mismatch and . Figure 2 is drawn on the previous result [4], and is in particular emphasized for the ferrous BMGs. In Fig. 2 (a), atomic radii of elements are plotted in sequence from the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the horizontal axis. ...
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... discussed in the present study. The ∆r is calculated with ∆r = |2 . (r a -r b )/(r a +r b )|, where r a and r b denote atomic radius of A and B atoms, respectively. Fig. 2 shows characteristics of BMGs with respects to atomic size mismatch and . Figure 2 is drawn on the previous result [4], and is in particular emphasized for the ferrous BMGs. In Fig. 2 (a), atomic radii of elements are plotted in sequence from the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the horizontal axis. Figure 2 (b) is obtained by tracing the atomic radii of elements from Fig. 2 (a) for the constituent elements of typical ternary BMGs, and solute elements for ferrous BMGs. Fig. ...
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... Fig. 2 (a), atomic radii of elements are plotted in sequence from the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the horizontal axis. Figure 2 (b) is obtained by tracing the atomic radii of elements from Fig. 2 (a) for the constituent elements of typical ternary BMGs, and solute elements for ferrous BMGs. Fig. 2 (c) summarizes the characteristics of 's in ternary BMGs. ...
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... Fig. 2 (a), atomic radii of elements are plotted in sequence from the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the horizontal axis. Figure 2 (b) is obtained by tracing the atomic radii of elements from Fig. 2 (a) for the constituent elements of typical ternary BMGs, and solute elements for ferrous BMGs. Fig. 2 (c) summarizes the characteristics of 's in ternary BMGs. ...
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... In Fig. 2 (a), atomic radii of elements are plotted in sequence from the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the horizontal axis. Figure 2 (b) is obtained by tracing the atomic radii of elements from Fig. 2 (a) for the constituent elements of typical ternary BMGs, and solute elements for ferrous BMGs. Fig. 2 (c) summarizes the characteristics of 's in ternary BMGs. In Figs. 2 (b) and (c), the main elements are drawn in solid circles in which the symbol of the element are written in white. The main alloying element of ternary G-I, G-V and G-VII, ternary G-II and G-IV, and ternary G-VI BMGs tends to be the largest, intermediate and smallest ...
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... the smallest (H) to the largest (Cs) so as to avoid overlapping of each element for the horizontal axis. Figure 2 (b) is obtained by tracing the atomic radii of elements from Fig. 2 (a) for the constituent elements of typical ternary BMGs, and solute elements for ferrous BMGs. Fig. 2 (c) summarizes the characteristics of 's in ternary BMGs. In Figs. 2 (b) and (c), the main elements are drawn in solid circles in which the symbol of the element are written in white. The main alloying element of ternary G-I, G-V and G-VII, ternary G-II and G-IV, and ternary G-VI BMGs tends to be the largest, intermediate and smallest atomic radius compared to the other alloying elements, respectively. This ...
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... other alloying elements, respectively. This tendency indicates disadvantages for the fabrication of ferrous BMGs due to the location of atomic radius of ferrous-group elements (Fe, Ni, Co) and restrictions with respects to . That is, it is apparent that the atomic radius of Fe, Co and Ni locates at the smaller size region in whole the ranges in Fig. 2 (a), which reduces the numbers of candidate solute elements among the whole elements. In addition, for the formation of ferrous BMGs, there exists strict restrictions with respect to about the ratios and ranges of , which are shown in Fig. 2 (c). Presumably, these restrictions also reduce the numbers of alloy systems to be formed as ...
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... apparent that the atomic radius of Fe, Co and Ni locates at the smaller size region in whole the ranges in Fig. 2 (a), which reduces the numbers of candidate solute elements among the whole elements. In addition, for the formation of ferrous BMGs, there exists strict restrictions with respect to about the ratios and ranges of , which are shown in Fig. 2 (c). Presumably, these restrictions also reduce the numbers of alloy systems to be formed as ferrous BMGs compared to those of the other BMGs. The tendency and restrictions of ferrous BMGs are interpreted the necessity of multicomponent alloying for the formation of ferrous BMGs in which as many as six or more constituent elements is ...
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... to ferrous BMGs, Mg-Cu-Y BMG which belongs to G-VI exhibits the similar tendency with respects to the main element and ∆ 's of the constituent elements. However, the atomic radius of Mg locates at the middle region in whole the ranges in Fig. 2 (a), thus, the restrictions for the formation of BMGs are not rigid as the ferrous BMGs. These tendencies and restrictions are presumably reflected by the maximum sample thickness of BMGs reported previously [1] that maximum sample thickness of Mg-and Fe-based BMGs are approximately 10 and 6 mm, respectively [1]. Table 2 shows a part of ...
Citations
... HEAs altered slightly, whereas the corrosion current density tended to decrease. Due to the relatively negative mixing enthalpy between Cr and Si [34], the post-added Cr contributed to forming a corrosion-resistant Cr3Si phase. Despite the fact that Cr3Si phase reduced the corrosion rate of the alloy, the Cr element in intermetallic compounds (Cr3Si) could not generate a uniform passivation film. ...
... When 1.0 < x < 1.6, the corrosion potential of AlSi 0.5 Cr x Co 0.2 Ni HEAs altered slightly, whereas the corrosion current density tended to decrease. Due to the relatively negative mixing enthalpy between Cr and Si [34], the post-added Cr contributed to forming a corrosion-resistant Cr 3 Si phase. Despite the fact that Cr 3 Si phase reduced the corrosion rate of the alloy, the Cr element in intermetallic compounds (Cr 3 Si) could not generate a uniform passivation film. ...
The Al-Si-Cr-Co-Ni High Entropy Alloy (HEA) with low density (about 5.4 g/cm3) and excellent performance had significant potential in the lightweight engineering material field. To further research and optimize the Al-Si-Cr-Co-Ni system HEA, the influences of element Cr on the microstructures and performances of lightweight AlSi0.5CrxCo0.2Ni (in mole ratio, x = 1.0, 1.2, 1.4, 1.6, and 1.8) HEAs were investigated. The experiment results manifested that AlSi0.5CrxCo0.2Ni HEAs were composed of A2 (Cr-rich), B2 (Ni-Al), and Cr3Si phases, indicating that the addition of Cr did not result in the formation of a new phase. However, ample Cr increased the Cr3Si phase composition, further ensuring the high hardness (average HV 981.2) of HEAs. Electrochemical tests demonstrated that HEAs with elevated Cr3Si and A2 phases afforded greater corrosion resistance, and the improvement in corrosion was more pronounced when x > 1.6. This work is crucial in the development of lightweight engineering HEAs, which are of tremendous practical utility in the fields of cutting tools, hard coating, etc.
... The existence of Ni atoms in the vicinity of Fe ones reduced the magnetic moment per atom and, therefore, reduced magnetization. The saturation magnetization strongly depends on chemical composition, local environment of the magnetic atoms and their electronic structure [30]. The sharp decrease of magnetization between 10 and 40 h of milling can be attributed to the dissolution of the Y atoms into the microstructure of the Al 82 Fe 14 Ni 2 Y 2 powders. ...
Amorphous Al82Fe14Ni2Y2 and Al82Fe14Ti2Y2 alloys were synthesized by mechanical alloying. Morphological and structural characterizations of the powders, milled for different periods of time, were investigated by scanning electron microscopy and X-ray diffraction methods. The dissolution of Ni and Al into the Fe lattice led to the formation of Fe(Ni,Al) solid solutions in Al82Fe14Ni2Y2 alloy after 20 h of milling. A slower dissolution of Ti and Al into the Fe lattice can be observed for Al82Fe14Ti2Y2 after milling 40 h. The fully amorphous structure can be obtained for Al82Fe14Ni2Y2 after 60 h of milling. The amorphization of the Al82Fe14Ti2Y2 sample milled for 100 h was not complete, and a partially nanocrystal phase of Ti was still present. Coercivity (Hc) and the saturation magnetization (Ms) of as-milled powders decreased markedly with increasing milling time. The magnetic properties of the alloys were consistent with the structural changing during milling process. The amorphous phase transforms into fcc-Al and metallic compounds after annealed DSC treatment.
... While the particle size distribution of Al82Fe16Ni2 and Al82Fe16Cu2 remained nearly the same in the lower size range, the cumulative size distribution curve of Al82Fe16Ti2 shifted rightwards, indicating that particle size shifted to a larger micron range (<30 µm at 90% volume fraction). Table 1 listed atomic radii mismatch (in %) and enthalpies of mixing (in kJ/mole) for Al, Fe, Ni, Ti, Cu, Y, and La binary systems, according to [30,31]. The three basic empirical rules, for the achievement of high glass-forming ability, are: (1) the alloy must contain at least three components; (2) a significant atomic size difference among the main constituent elements in the alloy should be above 12%; (3) there should be a negative heat of mixing among the major constituent elements in the alloy system [32,33]. ...
... It is evident that the atomic mismatch does not significantly influence the glass-forming ability (GFA) in Al-Fe alloys produced by the mechanical alloying technique because of the nearly similar atomic size of Ti, Ni, and Cu transition elements. However, the amorphization process varied with the mixing Table 1 listed atomic radii mismatch (in %) and enthalpies of mixing (in kJ/mole) for Al, Fe, Ni, Ti, Cu, Y, and La binary systems, according to [30,31]. The three basic empirical rules, for the achievement of high glass-forming ability, are: (1) the alloy must contain at least three components; (2) a significant atomic size difference among the main constituent elements in the alloy should be above 12%; (3) there should be a negative heat of mixing among the major constituent elements in the alloy system [32,33]. ...
In the present study, the thermal stability and crystallization behavior of mechanical alloyed metallic glassy Al82Fe16Ti2, Al82Fe16Ni2, and Al82Fe16Cu2 were investigated. The microstructure of the milled powders was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed remarkable distinction in thermal stability of the alloys by varying only two atomic percentages of transition elements. Among them, Al82Fe16Ti2 alloy shows the highest thermal stability compared to the others. In the crystallization process, exothermal peaks corresponding to precipitation of fcc-Al and intermetallic phases from amorphous matrix were observed.
... In the Pettifor map, all the known binary compounds are written in the form of A 1−x B x , the abscissa is the Mendeleev ordinal of A, and the ordinate is the Mendeleev ordinal of B. Different patterns represent the structures of different binary compounds. The Mendeleev number and the Pettifor map have emerged as the important parameter for choosing the promising alloys in the field of ferrous bulk metallic glasses (Takeuchi and Inoue, 2006), quasicrystalline intermetallics (Ranganathan and Inoue, 2006), and binary metal hydrides (Matysik et al., 2014), and they also offer many advantages in searching HEAs (Takeuchi, 2016). ...
High-entropy alloys (HEAs) open up new doors for their novel design principles and excellent properties. In order to explore the huge compositional and microstructural spaces more effectively, high-throughput calculation techniques are put forward, overcoming the time-consuming and laboriousness of traditional experiments. Here we present and discuss four different calculation methods that are usually applied to accelerate the development of novel HEA compositions, that is, empirical models, first-principles calculations, calculation of phase diagrams (CALPHAD), and machine learning. The empirical model and the machine learning are both based on summary and analysis, while the latter is more believable for the use of multiple algorithms. The first-principles calculations are based on quantum mechanics and several open source databases, and it can also provide the finer atomic information for the thermodynamic analysis of CALPHAD and machine learning. We illustrate the advantages, disadvantages, and application range of these techniques, and compare them with each other to provide some guidance for HEA study.
... Until now, in the case of high entropy alloys, the study of magnetic, elasticity, and corrosion-resistance properties prevails [1][2][3][11][12][13][14][15][16][17]. The paper [18] analyses the properties of the AlCuAgTi system high entropy alloy proposed to be used for metal brazing. ...
The paper presents the microstructure and corrosion behavior of an AlTiNiCuAgSn new equiatomic multicomponent alloy. The alloy was obtained using the vacuum arc remelting (VAR) technique in MRF-ABJ900 equipment. The microstructural analysis was performed by optical and scanning electron microscopy (SEM microscope, SEM-EDS) and the phase transformations were highlighted by dilatometric analysis and differential thermal analysis (DTA). The results show that the as-cast alloy microstructure is three-phase, with an average microhardness of 487 HV0.1/15. The obtained alloy could be included in the group of compositionally complex alloys (CCA). The corrosion resistance was studied using the potentiodynamic method in saline solution with 3.5% NaCl. Considering the high corrosion resistance, the obtained alloy can be used for surface coating applications.
... In this work we investigated magnetic susceptibility and electric resistivity of the alloy with the base composition Co 47 Fe 20.9 B 21.2 Si 4.6 Nb 6.3 as well as the influence of gallium additions on its magnetic and electric properties. This element (Ga) was chosen because it matches rather well the criteria of increased GFA given by A. Inoue: the difference in atomic radius against the main elements of the alloy (cobalt and iron) is about 12% [8]; the systems Co-Ga and Co-Sb are characterized by the negative heat of mixing ( H up to -44 kJ/mol in case of Co-Ga pair [9,10] and up to -2 kJ/mol for Fe-Ga [10]). ...
... The as-prepared master alloy was subsequently purified by fluxing. The chemical composition of the purified alloy, Co 47 Fe 20. 9 coupled plasma spectroscopy. The additions of gallium (2 and 3 at.%) ...
The influence of small additions of gallium on electric resistivity and magnetic susceptibility of the bulk glass forming Co47Fe20.9B21.2Si4.6
Nb
6.3
alloy was studied in a wide temperature range up to 1830 K. Gallium atoms were found to increase resistivity but decrease susceptibility of the alloy. The suppositions about clusters surrounding Ga atoms in the melt and new GFA criterion are given
... In this work we investigated magnetic susceptibility of the alloy with the base composition Co 47 Fe 20.9 B 21.2 Si 4.6 Nb 6.3 as well as the influence of gallium and antimony additions on magnetic properties, electronic structure and undercooling of CoFeBSiNb alloys with a similar chemical composition as the above mentioned one. These two elements were chosen because they match rather well the criterion of increased GFA given by A. Inoue: differences in atomic radii against the main elements of the alloy (cobalt and iron) are about 12% [7]; the systems Co-Ga and Co-Sb are characterized by the negative heat of mixing (ΔH up to À 11 kJ/mol in case of Co-Ga pair [8] and up to À 14 kJ/mol for Co-Sb [9]). ...
Rapidly quenched Co-Fe-B-Si-Nb-(Ga) ribbons were investigated. We have concentrated on the influence of small addition of gallium (2 at.%) into base composition Co47Fe20.9B21.2Si4.6Nb6.3 on structure, thermal and magnetic properties in as-cast state and upon transition to nanocrystalline state. Structure of the samples was examined by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). Thermal stability associated with glass transition temperature (Tg), crystallization temperature (Tx) and supercooled liquid region (ΔTx=Tx-Tg) were examined by differential scanning calorimetry (DSC). The Curie temperature of the investigated ribbons was determined by magnetic thermogravimetry analysis (TGA).
