C14 Type Research Articles

Structural-regulation of Laves phase high-entropy alloys to catalytically enhance hydrogen desorption from MgH2

Magnesium hydride (MgH2) is a promising hydrogen storage material, but slow hydrogen desorption kinetics and poor cycling stability still limit its development. Catalytic doping was demonstrated to provide effective solution for it. In this work, we develop novel Zr-based high-entropy alloys (HEAs) catalysts with different Laves phase structures to improve the hydrogen storage in MgH2. It was demonstrated that the catalyst grain size, defect density and lattice distortion have a great influence on the performance of HEAs catalysts. Specially, the C15 type Laves phase HEA exhibits a better catalytic effect than that of C14 type. The introduction of HEAs with "hydrogen pump" effect would shift the rate-limiting step of MgH2 hydrogen desorption from two-dimensional nucleation growth to two-dimension phase boundary migration, which makes it exhibit both great better hydrogen desorption kinetics enhanced by nine times and cycling stability with 92 % capacity retention after 30 cycles. This work not only highlights the impact of Laves phase crystal structure regulation on HEAs catalysts, but also provides insights into the design and development of HEAs catalysts to improve the hydrogen storage performance of MgH2.

Site occupancy and electronic properties of NbCo2 Laves phases doped with Re

In the present work, we have carried out an extensive first-principles study of Re doped C14, C15 and C36 type NbCo2 Laves phases, respectively. The geometric optimized lattice constants of Laves phases decrease as Re replaces Nb site, while increase as Re replaces Co site. The binding energy and the formation energy indicate that Re will promote the formation of Laves phases. The results of electronic properties (density of states and charge density difference) reveal that Re has a strong bond with its NN (nearest neighborhood) Co and NN Nb atoms, which were mainly attributed to the d-d hybridization. Besides, as Re doping Co site, the increase of charge density between Re and its NN atoms indicates that Re prefers to occupy the Co site.

Microstructure and mechanical performances of novel multi-phase refractory high entropy alloys in Ti-Zr-V-Mo fabricated by vacuum arc melting

In this work, four novel refractory high entropy alloys (RHEAs) of the Ti-Zr-V-Mo system have been developed and characterized by experiments. Except for the RHEA of Ti0.5ZrVMo with phase constituents of bcc + pm-3n + Laves (C15 type), the phase constituents in the as-solidified condition of all the other three RHEAs can be denoted as bcc1 + bcc2 + Laves (C15 type). All four alloys exhibited typical dendrite morphology with coarse dendrites and thin inter-dendritic regions. Besides, there were certain small-sized precipitated particles dispersed in the inter-dendrite matrix. In TiZrV3Mo, bcc structured solid solution phases of (TiMoV) and (TiZrV) as well as one C15 Laves phase of (MoV) Zr were confirmed. The equiatomic RHEA of TiZrVMo exhibited a yield strength of 1323.0 MPa, compressive strength of 1521.9 MPa and a compressive strain of 4.5%, also with double bcc structured solid solution phases of (TiMo) and (TiZr) as well as the Laves precipitate of Zr0.5Ti0.5Mo2. The multi-phase RHEAs with solid solutions and minor precipitates with excellent performances by deformation incompatibility between phases, provide a certain reference for the composition design and the industrial development of RHEAs in practical applications.

Microstructure and hydrogen storage properties of Zr-based AB2-type high entropy alloys

This paper reports the partial substitution of Fe, Co, Ni and Cu for Mn in ZrMnCr0.5V0.5 alloy with to obtain ZrMn0.5Cr0.5V0.5M0.5 (M = Fe, Co, Ni and Cu) high entropy alloys. These alloy samples are prepared by electric arc melting, and their microstructure and hydrogen storage properties are investigated in detail. Structural analysis results show that all the five alloys consist of C14 type Laves primary phase. Metastable cubic phase can be observed in ZrMnCr0.5V0.5 and Fe-, Co-substituted alloys, while ZrNi, Cu10Zr7 and Cu8Zr3 phase secondary phases exist in Ni- and Cu-substituted alloys. Hydrogen storage testing results show that elemental substitution greatly improves the first activation properties of the alloys. All the five alloys can absorb hydrogen rapidly when the temperature is above 100 ℃, while the elemental substitution significantly affects the hydrogen absorption kinetics at lower temperatures. Compared with other four alloys, the Cu-substituted alloy has two kinds of Cu-Zr secondary phases, resulting in a poorer hydrogen absorption performance. Pressure-composition isotherms (P-C-T) test results show that all these alloys have very sloping absorption and desorption plateaus. It is also found that all the alloy particles are pulverized spontaneously during hydrogenation cycles, but there is no clearly change on phase structure of C14 type Laves phase, and the alloys show a good cycling performance. Among these alloys, the ZrMn0.5Cr0.5V0.5Fe0.5 alloy has the best hydrogen storage performance because it has the shortest activation time and fast hydrogen absorption at room temperatures.

Studies of the effect of Hf doping on the electrochemical performance of C15 Laves type metal hydride battery anode alloys

This paper focuses on the studies of the electrochemical performance of arc-melted Hf-modified Ti-Zr based AB2 Laves type metal hydride battery anode alloys with composition HfxZr24-xTi6.5V3.9Mn22.2Fe3.8Ni38La0.3Sn0.3 (x = 1–4). The phase composition and the morphology of the alloys were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Metal-gas interactions and electrochemical performances were studied by building PCT diagrams and by electrochemical tests performed in a 9 N KOH electrolyte solution at ambient temperature when using the half-cells in a three-electrode assembly.All studied alloys were two-phase and contained the Laves phase intermetallics of C15 (major constituent) and C14 (minor constituent) types. An increase in Hf content caused a growth of the abundance of the C14 phase and was accompanied by a decrease in the electrochemical discharge capacities, exchange current densities, and H diffusion rates as compared to the Hf-free alloy. Among the Hf-containing alloys, an introduction of 2 wt% Hf into the alloy's composition resulted in a higher H diffusion rate, while the highest H storage capacity has been reached for the alloy with the lowest, 1 wt%, content of Hf. The surface of the alloys contained catalysing hydrogen exchange metallic nickel clusters with the highest enrichment observed for the 2 wt% Hf alloy. An influence of Hf on the hydrogen storage and electrochemical performance can be understood in terms of the modification of the intrinsic properties of the alloys following a substitution (Zr/Ti) → Hf as C15 type alloys show the fastest hydrogen diffusion rates while a gradually increasing content of the hexagonal C14 type in the Hf-containing alloys slows down the H diffusion process.

Analysis of phase transformation and deformation behaviors on Laves phase of as-cast (CoCuFeNi)100-xZrx high entropy alloys

In this study, the effects of Zr contents on the microstructure, phase, mechanical properties and deformation behavior of CoCuFeNi medium entropy alloy (MEA) have been investigated. With increasing Zr contents to 7 at%, Ni-Zr C14 type Laves phase formed due to high negative mixing enthalpy between Ni and Zr contents which display eutectic morphologies in matrix. The mechanical properties increased from 232 MPa to 446 MPa without decreasing plastic strain. Furthermore, the enhanced work-hardening rate was observed according to adding Zr. By the TEM analysis, we can confirm that the observed deformation behavior is relative to the phase transformation of Laves phase, in which C14 type Laves phase transformed into C15 type Laves phase through synchroshear process. Numerous dislocation formed in FCC phase piled up in C14 Laves/FCC interface, which made the enhanced hardenability. On the other hand, the transformed C15 Laves showing better dislocation mobility enable dislocation to glide into C15 Laves/FCC interface, which allowed the stress-strain curve to change the slope. In this study, our research provides the detailed transformation mechanism and deformation behavior in terms of dislocation motion.

Notable hydrogen storage in Ti–Zr–V–Cr–Ni high entropy alloy

In the present investigation, we discussed the synthesis, structural and hydrogen storage behavior of high-entropy Ti–Zr–V–Cr–Ni equiatomic intermetallic alloy. This alloy was synthesized by arc melting in an argon atmosphere where base pressure was in the order of 10−5 atm before purging with argon gas. The X-ray diffraction study revealed that the alloy is C14 type hexagonal Laves phase. The pressure composition isotherms (PCI) of this alloy were investigated with pressure ranges at 0–40 atmosphere. The total hydrogen storage capacities were found to be 1.52 wt%. The reversible hydrogen storage capacity was quite stable and only slight decreases in the storage capacity was observed after 10 cycles during hydrogen soaking. The demonstrations of hydrogen storage capacity of the Ti–Zr–V–Cr–Ni equiatomic alloy were thus established, indicating the future potential of developing this class of high entropy intermetallic based materials for hydrogen storage.

Atomic site occupancy of alloying elements and Laves phase stability in γ-γ′ Co-base superalloys

The atomic site occupancy of alloying elements in the ZrCo2 and HfCo2 based Laves phases formed in the Co-9Al-9W-2Zr and Co-9Al-9W-2Hf alloys was experimentally determined by the combined techniques of energy-dispersive X-ray spectroscopy mapping with atomic resolution and the atom location by channeling enhanced microanalysis (ALCHEMI) method. The results show that both Al and W occupy the Zr site in the C15 and the Hf site in the C36 crystal structure. The atomic locations of Al and W were further confirmed by comparing calculated inelastic cross-sections with experimental ALCHEMI results. Using the determined atomic site occupancies of alloying elements, special quasirandom structure solid solution models with 192 atoms were constructed and employed in first-principles calculations. It is found theoretically that the energy of formation of the C15 structure is always lower than that of the C36 structure at 0 K in both ZrCo2 and HfCo2 phases, no matter whether Al and W are incorporated or not. However, further ab initio molecular dynamics simulations suggest that lattice vibration at finite temperature contributes significantly to the phase stability, stabilizing the C36 structure compared to the C15 type for the (Hf, Al, W)Co2 phase at finite temperature, which fits well with the experimental findings.

Theoretical and experimental study on phase stability of TiVZrMoW refractory high entropy alloy

ABSTRACT An equiatomic quinary TiVZrMoW refractory high entropy alloy (RHEA) is selected for studying phase evolution and stability. The prediction of phases that may form on synthesis is made by (i) Semi-empirical /empirical methods (based on extended Hume-Rothery rules), (ii) CALPHAD and (iii) ab-initio methods. Mixing enthalpy (calculated by Miedema method) and valence electron concentration predicted the formation of the BCC phase (; and VEC = 5). However, the atomic mismatch factor, δ (7.17%) value being higher than the desired value, can de-stabilize the lattice to form a multi-phase structure. CALPHAD technique predicted that at room temperature three BCC and two Laves phases would form. The enthalpy of mixing (4.25 kJ/mol) calculated using Density Functional Theory (DFT) also suggests phase separation at room temperature. The phases and microstructure that evolved in the as-cast and annealed samples are studied by X-ray diffraction (XRD), scanning electron and transmission electron microscopy (TEM) techniques. Two BCC phases and a minor amount of ordered B2 and C15 type Laves phase are found to co-exist in the as-cast sample. The primary BCC phase (BCC#1) is rich in Mo and W (a = 3.17 ± 0.02 Å), while the minor BCC phase (BCC#2) is rich in Zr and Ti (a = 3.65 ± 0.02 Å). The annealed sample shows the transformation of both the disordered BCC phase to the ordered B2 phases and the increase in the amount of C15 Laves phase. The phase evolution and their relative stability in this RHEA has been discussed after analysing the experimental and theoretical results.

Investigation of microstructure and wear resistance of laser-clad CoCrNiTi and CrFeNiTi medium-entropy alloy coatings on Ti sheet

Two medium-entropy alloy coatings (MEACs), CoCrNiTi and CrFeNiTi, were successfully prepared on pure Ti sheet by utilizing pulsed laser cladding. Microstructural characterization reveals that both the MEACs are mainly comprised of BCC solid-solution phase along with interdendritic Cr2Ti Laves phase (C14 type) due to element segregation. Hardness and wear tests show that the CoCrNiTi MEAC has a hardness of 762 ± 32 HV and a specific wear rate of 1.7 × 10−5 mm3·N−1·m−1, and those of the CrFeNiTi MEAC are 820 ± 34 HV and 2.8 × 10−5 mm3·N−1·m−1, respectively, both of which are markedly superior to the pure Ti substrate (114 ± 5 HV and 5.4 × 10−4 mm3·N−1·m−1). Comprehensive analyses suggest that the excellent properties of the MEACs can be attributed to combined strengthening effects of solid-solution, short-range order, grain refinement and the Cr2Ti Laves phase.

Metallothermal synthesis of the Laves phase TaCr2 from oxide raw materials

The refractory Laves phase TaCr2 of two compositions (series) was synthesized by the metallothermal (hydride-calcium) method from oxide raw materials (Cr2O3 + Ta2O5). The synthesis temperature was 1200 oC, while the excess of the reducing agent CaH2 was varied relative to the theoretically required for the complete reduction of oxides. It is shown that regardless of the excess of the reducing agent or in its complete absence, the resulting  powders have the required chemical composition (composition 1: calculated Cr content — 37.38% (wt.), actual — 37.50±0.85% (wt.); composition 2: calculated Cr content — 35.30% (wt.), actual — 35.38±0.31% (wt.)). No significant losses of Cr and Ta were observed during the synthesis of the Laves phase under the conditions of hydride-calcium reduction of Cr2O3 and Ta2O5. All prepared powders contained ~ 0.25% (wt.) oxygen and 0.025% (wt.) calcium. This is a good result for experimental batches first obtained by this method. Powders of the first series (composition 1), regardless of the excess of CaH2, contained no less than 85% (wt.) of the TaCr2 phase of the С15 type and ~ 10% (wt.) of the Cr(Ta) solid solution. However, when the excess of the reducing agent was >50 wt%, a high-temperature modification of the TaCr2 phase with a C14-type hexagonal lattice came in sight. The same picture was observed in the second series of experiments (composition 2). In all cases, the amount of the C14 type TaCr2 phase did not exceed 5% (wt.). Powders of composition 2 contained no less than 90% (wt.) of the C15 type TaCr2 phase or 95% (wt.), if there were two modifications C15 + C14. Depending on the excess of the CaH2 reductant, the alloys contained small amounts of Cr(Ta) or Ta2H hydride. In both series, the powder particles had a finely dispersed spongy structure; large particles of regular shape were present in an insignificant amount. This work was carried out with financial support of the government of the Tula region (grant for work in the field of science and technology No. DS / 161 dated October 29, 2020).

Magnetic and Magnetocaloric Effect of Laves Phase Compounds Er(Fe0.8−xMn0.2−yCox+y)2 with x, y = 0.0 or 0.1

Magnetic and magnetocaloric effect (MCE) of the Er(Fe0.8−xMn0.2−yCox+y)2 Laves phase-type compounds have been investigated. X-ray diffraction (XRD) analysis has revealed that these compounds crystallize with the C15 type Laves phase structure (Space Group Fd-3m). The magnetization curves indicate a ferri-magnetic-ordering resulting of the antiparallel coupling between the moments of the heavy rare earth Er and the transition metal (TM). The partial substitution of Fe/Mn by Co increases the Curie temperature from 355 K for Er(Fe0.8Mn0.2)2 to 475, 550, and 555 K for Er(Fe0.7Mn0.2Co0.1)2, Er(Fe0.8Mn0.1Co0.1)2, and Er(Fe0.7Mn0.1Co0.2)2, respectively. According to the nature of the TM elements, arguments were presented forwards either Molecular Field or Spin Fluctuation Theory, even Stoner type pictures should be considered for. MCE was calculated according to the Maxwell relation based on isotherm magnetization measurements. The magnetic entropy change (−∆SM) observed on a 300–400 K temperature range can be understood in terms of a Spin Fluctuation Theory picture supported by both the different magnetic polarization levels that were shared by the TM elements and the related interatomic exchange forces.

Identification of critical residues for the catalytic activity of ComQ, a Bacillus prenylation enzyme for quorum sensing, by using a simple bioassay system.

Bacillus ComQ participates in the biosynthesis of a quorum-sensing signaling molecule (ComX pheromone) through catalyzing the prenylation at a Trp residue of the precursor peptide (pre-ComX) with geranyl diphosphate (C10 type) or farnesyl diphosphate (C15 type). We hypothesized that several residues specifically conserved among either type of ComQs are important for their substrate specificities. Using a simple bioassay, we revealed that Phe63, Asn186, and Gly190 in ComQRO-E-2 (C10 type) were nondisplaceable to Ser63, Gly186, and Val190, the corresponding residues in the C15-type ComQ, respectively. A three-dimensional model suggested that the 186th and 190th residues are involved in the pre-ComX binding. In vitro analysis showed that substitution of Phe63 with Ser in ComQRO-E-2 significantly reduced the geranylation activity but substantially enhanced the farnesylation activity, whereas substitution of Ser63 with Phe in ComQ168 (C15 type) reduced the farnesylation activity. Therefore, the 63rd residue was found to be significant for the prenyl-substrate preference.Abbreviations: GPP: geranyl diphosphate; FPP: farnesyl diphosphate; IPP: isopentenyl diphosphate; GGPP: geranylgeranyl diphosphate; FARM: first aspartate-rich motif; SARM: second aspartate-rich motif; β-Gal: β-galactosidase; TBABG: tryptose blood agar base supplemented with glucose; X-gal: 5-bromo-4-chloro-3-indolyl-β-D-galactoside.

Formation and stability of C14 type Laves phase in multi component high-entropy alloys

The present investigation reports the formation and stability of multi-component AB2-type Laves phase in Ti–Zr–Ni (V, Cr, Fe, Mn, Co)ternary to octonary alloys system. To probe the formation and stability of AB2-type Laves phase in high-entropy alloys, a series of multi-component alloys have been synthesized via melting under protective Ar atmosphere and subsequent annealing at 525 K for 40 h. Systematic investigation has been carried out to understand phase stability using both thermodynamic and parametric approaches. X-ray diffraction measurement and Rietveld analysis indicate the formation of C14 Laves phase in multi-component alloys. The enthalpy of mixing (ΔHmix), size difference (δ) and valence electron concentrations (VEC) have been found to play stellar role in controlling the formation of multi-component Laves phase in these alloys. The valence electron concentrations and electrons per atom ratio (e/a) dictate the choice of elements for the stabilization of Laves phase in these high-entropy alloys.

Investigation of Crystal Structure, Microstructure, and Hydrogenation Behavior of Heat-Treated Ti52V12Cr36 Alloy

The effect of heat treatment on the first hydrogenation of Body Centred Cubic (BCC) Ti52V12Cr36 alloy was investigated. It was found that, after a one week heat treatment at 1273 K, BCC phase abundance was greatly reduced by heat treatment. The crystal structure changed from BCC to a complex multi-phase pattern of BCC phase, C15 type Laves phase and α-Ti. The network of α-Ti phase was broader after heat treatment. The heat-treatment eliminated the incubation time of the first hydrogenation and improved the kinetics, but the total hydrogen capacity was reduced by 30%.

Gum-like mechanical behavior of a partially ordered Al5Nb24Ti40V5Zr26 high entropy alloy

Microstructure and mechanical behavior of a new bcc Al5Nb24Ti40V5Zr26 high-entropy alloy in the as-cast, cold-rolled and recrystallized conditions were studied. In the as-cast condition, the Al5Nb24Ti40V5Zr26 alloy had a single bcc phase coarse-grained (~80 μm) structure. After cold rolling to a total thickness strain 80% the alloy demonstrated typical of deformed metals tensile behavior with a short hardening stage and early necking. Annealing at 800 °C resulted in recrystallization of the matrix and formation of a small fraction of C14 type Laves phase particles. After annealing at 1100 °C, a partial B2 ordering of the matrix phase was found. In the annealed condition, the alloy showed some typical of gum metals features associated with low work hardening and large elongation. The manifestation of a gum-like behavior can be ascribed to the formation of dislocation channels due to the local disordering of the bcc matrix in shear planes. In addition, an unusual (inverse) dependence of yield strength on the recrystallized grain size was observed, most possibly due to a different degree of ordering of the matrix phase.

The Co–Ti system revisited: About the cubic-to-hexagonal Laves phase transformation and other controversial features of the phase diagram

The Co–Ti system is one of the important systems for the development of Co-based superalloys and it is the only binary Co-X system where the characteristic, fine-scaled γ/γ′ microstructures (fcc-Co with fcc L12-ordered TiCo3) can form. Surprisingly, the phase relations and invariant reaction temperatures in the Co-rich part of the system are not very well established and there are fundamental inconsistencies between different versions of the phase diagram. Crucial points such as the type of formation reaction of the γ′ phase TiCo3 from the melt are unclear. The system is not only of high scientific interest because of the presence of the γ/γ’ microstructure, but also due to the occurrence of two different, stable polytypes of the Laves phase TiCo2 (hexagonal C36 and cubic C15 type). The phase fields of these two polytypes should be separated by a two-phase field the existence of which however has never been clearly proven. A re-investigation of the Co-rich part of the phase diagram (0–50 at.% Ti) including all invariant reactions as well as the liquidus, solidus, and solvus lines was performed by not only making use of equilibrated alloys but also applying diffusion couples.

Improved trade-off between strength and plasticity in titanium based metastable beta type Ti-Zr-Fe-Sn alloys

An impressive strengthening ability of Laves phases is favorable to develop titanium alloys with an improved trade-off between strength and plasticity. Therefore, the Ti-xZr-7Fe-ySn (x = 25, 30, 35 wt% and y = 1, 2 wt%) alloys were first designed in such a manner that a Laves phase would precipitate in these alloys and then the investigated alloys were produced by cold crucible levitation melting. A hexagonal close-packed C14 type Laves phase along with a dominant fraction of body-centered cubic β phase are formed in all the as-cast Ti-xZr-7Fe-ySn alloys except in Ti-25Zr-7Fe-2Sn. The volume fraction of the Laves-C14 phase is found to be sensitive to the quantities of Zr and Sn. Amongst all the investigated alloys, Ti-35Zr-7Fe-2Sn shows a better dislocation-pinning ability in terms of dislocation density (3.96 × 1015 m−2), yield strength (1359 MPa) and hardness (437 HV), whereas Ti-25Zr-7Fe-1Sn shows a better deformation ability in terms of compressive strain at failure (36.2%) and plastic strain (31.9%). Crack propagation, regions of dimples and deformation bands are examined in the fracture analyses. Moreover, in this work, Ti-25Zr-7Fe-1Sn exhibits the best strength and plasticity trade-off in terms of a product of ultimate strength and compressive strain at failure (77.4 GPa %).

High‐pressure hydrogen storage properties of Ti x Cr 1 − y Fe y Mn 1.0 alloys

TixCr1 − yFeyMn1.0 (x = 1.02, 1.05, 1.1, 0.05 ≤ y ≤ 0.25) alloys were prepared by plasma arc melting and annealing at 1273 K for 2 hours. The XRD results show that the main phase of all alloys is the C14 type Laves phase, and a little secondary phase exists in a mixture of the binary alloy phase. The lattice parameters increase with Ti super-stoichiometry ratio increasing, whereas smaller lattice parameters emerge with increasing Fe stoichiometry content. Additionally, as the Ti super-stoichiometry ratio decreases, the pressure-composition-temperature measurements indicated that hydrogen absorption and desorption plateau pressures of TixCr0.9Fe0.1Mn1.0 (x = 1.1, 1.05, 1.02) alloys increase from 3.15, 0.67, to 5.94, 1.13 MPa at 233 K, respectively. On the other hand, with the Fe content increasing in Ti1.05Cr1 − yFeyMn1.0 (0.1 ≤ y ≤ 0.25) alloys from 0.1 to 0.25, the hydrogen desorption plateau pressures increased from 1.41 to 2.46 MPa at 243 K. The hydrogen desorption plateau slopes reduce to 0.2 with Ti super-stoichiometry ratio decreasing to 1.02, but the alloys are very difficult to activate for hydrogen absorption and cannot activate when the Fe substituting for Cr exceeds 0.2. The maximum hydrogen storage capacities were more than 1.85 wt% at 201 K. The reversible hydrogen storage capacities can remain more than 1.55 wt% at 271 K. The enthalpy and entropy for all hydride dehydrogenation are in the range of 21.0 to 25.5 kJ/mol H2 and 116 to 122 J mol−1 K−1, respectively. Our results suggest that Ti1.05Cr0.75Fe0.25Mn1.0 alloy with low enthalpy holds great promise for a high hydrogen pressure hybrid tank in a hydrogen refueling station (45 MPa at 333 K), and the other alloys of low cost may be used for a potable hybrid tank due to high dissociation pressure at 243 K and high volumetric density exceeding 40 kg/m3.

Studies of Zr-based C15 type metal hydride battery anode alloys prepared by rapid solidification

The objective of the present work was to study an interrelation between the conditions of the rapid solidification casting and electrochemical properties of a C15 Laves-type Zr-based metal hydride battery anode alloy. A 7-component overstoichiometric with B/A>2 alloy (Ni + Mn + V + Fe/Zr + Ti + La = 2.078) was Zr- and Ni-rich. Melt spinning was performed using as cast mother ingot at different rotation speeds of 5, 16.5, and 33 Hz with a 20-cm diameter Cu cooling wheel. The phase composition and morphology of the ribbons were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) along with X-ray energy dispersive spectroscopy (EDS). Partial Mn vaporization took place during the melt spinning and became more pronounced with the increase in the quenching rate at higher wheel rotation speeds. The SEM study showed a successful refinement and a more homogeneous distribution of La in the melt-spun alloys. However, the alloys demonstrated a more difficult activation performance as compared to the as-cast sample which was associated with introduction of Zr into the composition of the secondary La-and Ni-rich phase when quenching the melt. Presence of Zr in the secondary phase results in inferior rate of its hydrogenation. The formed during the rapid solidification (La,Zr) (Ni,Mn) secondary phase also contained a significant amount of oxygen additionally worsening the activation performance. The grain size gradually decreased from 3.5 μm in the as-cast alloy to approximately 250 nm for the melt spun sample obtained at the highest cooling rate. The two-phase alloys contained a mixture of two Laves type intermetallics, C15 and C14 ones. The abundance of the secondary C14 phase decreased with increase of the cooling rate as compared to the as-cast sample. The electrochemical performance was significantly affected by the compositional and microstructural changes associated with the variation in the cooling rate. The highest electrochemical discharge capacity of 414 mAh/g was obtained for the 16.5 Hz melt spun rate because of an optimized composition of the Laves phase. Furthermore, the diffusion coefficient of hydrogen in this alloy was the highest in a full state of charge, which indicates that faster hydrogen diffusion and shorter hydrogen diffusion paths were achieved via an application of the rapid solidification process. An optimization of the rapid solidification conditions is required to improve an activation behavior of the studied Laves types metal hydride anode alloys.