As-spun Ribbons Research Articles

Structure and magnetic properties of SmCo4.5Cu0.3Sn0.16Ga0.04 ribbons melt-spun at 10–40 m/s

The anisotropic Nd-Fe-B magnets prepared by as-spun ribbons using hot-pressing and hot-deformation methods have been commercialized. However, the Sm-Co magnets face challenges in obtaining strong c-axis deformation textures due to the absence of a low-melting intergranular phase to facilitate grain deformation. After simultaneously adding gradient low-melting metals of Cu, Sn, and Ga to SmCo5 alloy, SmCo4.5Cu0.3Sn0.16Ga0.04 ribbons were prepared by melt-spinning at 10–40 m/s. These ribbons comprise the Sm(Co, M)5 main phase, Sn-rich Sm2(Co, M)7 grain boundary phase, and Sm117Co55.58Sn115.94-type particulate phase. Notably, the ribbons melt-spun at 30 m/s contain the highest Cu, Sn, and Ga content in the grain boundary phase, making them most suitable for producing hot-pressed and hot-deformed magnets. Additionally, the ribbons melt-spun at 20 m/s have a maximum coercivity of 26.4 kOe, while those melt-spun at 40 m/s have the highest magnetization of 61.6 emu/g.

Plastic quasicrystal-containing alloys prepared by annealing pseudo-high entropy Zr70–75(Al, Ni, Cu, Ag)25–30 glassy alloys

A glassy (G) phase was formed for Zr-rich Zr70–75(Al, Ni, Cu, Ag)25–30 (atomic percent, at.%) melt-spun alloy ribbons. These glassy alloys exhibit the glass transition, followed by a supercooled liquid region and then three-stage crystallization. The glass transition temperature and the onset temperature for the first-stage crystallization (Tx1) decrease from 630 to 668 K, respectively for the 70Zr alloy to 619 and 652 K, respectively for the 75Zr alloy. The first-stage exothermic peak is due to the precipitation of an icosahedral quasicrystal (IQ) phase. The IQ particle size decreases from 10 nm to 6 nm with increasing Zr content from 70at.% to 74at.%. The [G + IQ] phases change to Zr2Ni + Zr2(Cu, Ag) phases after the second exothermic peak and then Zr2Ni + Zr2(Cu, Ag) + Zr5Al3 phases after the third stage. It is noticed that the as-spun glassy alloy ribbons as well as the annealed [G + IQ] phase ribbons exhibit good bending plasticity. Furthermore, the 70Zr thicker ribbons also exhibit high tensile fracture strength of 1090–1187 MPa and plastic elongation of 0.17 %–0.42 %. The fracture mode is similar to that of ordinary bulk metallic glasses. The Vickers hardness (Hv) is 480 for 70Zr alloy and decreases to 436 for 75Zr alloy. The precipitation of IQ phase causes a significant increase in Hv to about 554. The formations of glassy alloys with high Zr contents of 70at.%–75at.% by melt spinning as well as the [G + IQ] phase alloys with good bending plasticity by annealing hold promise for the creation of a new type of engineering material, transcending mere academic novelty.

Effects of Si addition on crystallization process and soft magnetic properties of high-Fe and high-Cu-content Fe–Si–B–P–Cu nanocrystalline alloys

In this study, the effects of Si content on the glass-forming ability (GFA), thermal stability, annealing window, nanocrystallization process, and soft magnetic properties (SMPs) of Fe86.3-xSixB10P2Cu1.7 (x = 0, 1, 2, 3, and 4, denoted as Si0, Si1, Si2, Si3, and Si4, respectively) alloys with high Fe and Cu contents were investigated. Moderate addition of Si (x = 1, 2, and 3) enhanced the GFA and suppressed the precipitation of compound phases, thus leading to a large crystallization temperature interval (ΔTx) exceeding 185 °C for the alloys. Appropriate addition of Si also resulted in the formation of high-density and fine pre-existing α-Fe nanocrystals in as-spun ribbons and a high growth active energy of α-Fe crystals during the subsequent nanocrystallization process for the Si1, Si2, and Si3 alloys, enhancing competitive growth between α-Fe crystals and resulting in fine nanostructure and excellent SMPs of the nanocrystalline alloys (NAs). As a result, the Si1, Si2, and Si3 NAs obtained by annealing at 420 °C for 30 min exhibited excellent SMPs with saturation magnetic flux density (Bs) up to 1.84 T and a low coercivity (Hc) of approximately 10 A/m. In addition, statistical analysis of the relationship between the average grain size (D) of α-Fe crystals and Hc values of the NAs indicated that an Hc α D3 dependence is observed when the D is less than approximately 30 nm, while this dependence follows the well-known Hc α D6 relationship when the D is above 30 nm. The dependency relationship between D and Hc of NAs can guide the selection of an appropriate annealing process to optimize their SMPs.

Microstructure and Magnetic Properties of Fe67.6-Pd32-In0.4 (at.%) Shape Memory Melt-Spun Ribbons.

Fe-~30 at.%Pd is a ferromagnetic shape memory alloy (SMA) with a reversible thermoelastic fcc-fct phase transformation. The advantage of adding a small amount of Indium to Fe-Pd SMAs is, among other things, the upward shift of the transformation temperatures, which allows us to maintain the material in the martensitic state (fct structure) at room temperature. In this work, we study the microstructure and the magnetic properties of nominally Fe67.6-Pd32-In0.4 (at.%) melt-spun ribbons. Energy-dispersive spectroscopy analysis showed a certain level of non-uniformity of Indium distribution in the as-spun ribbon. However, the attempt to homogenize the ribbon by annealing at 1273 K for 120 h resulted in an unfavoured structural change to bct martensite. Magneto strains induced by a 9 kOe magnetic field reached over 400 ppm for certain field orientations, which is around four times more than the magneto strains of near-binary Fe-Pd shape memory alloys.

Innovative microstructures in SmCo5-based ribbons regulated by Fe-Ni-Al-Ti alloy

We proposed a new measure to optimize the comprehensive magnetic properties of SmCo5 alloy. By compounding Fe-15Ni-3Al-1Ti (FNAT) alloy with high saturation magnetization and Sm(Co, Cu)5 matrix alloy in the liquid state, an innovative two-phase separation microstructure or cellular microstructure is formed after melt-spinning using the phase separation effect of the two alloys. At the same time, the element concentration, relative phase content, and microstructure are adjusted by adding different contents of FNAT alloy. The results show that FNAT addition promotes the as-spun ribbons phase separation (or spinodal decomposition) into Co-rich SmCo5- and Sm-Ni-rich CeCo5- or Sm2Co7-type phases. Adding 3 wt.% FNAT increases the coercivity, saturation magnetization, and remanence of the ribbons by 320.6 %, 39.8 %, and 82.8 %, respectively. Adding 5 wt.% FNAT promotes forming the Sm2(Co, M)7 cell-wall phase and increases the coercivity and remanence by 272.7 % and 48.1 %, respectively. Finally, the corresponding microstructure evolution models, magnetization, and demagnetization mechanisms are proposed.

Enhancing corrosion resistance of Al50Ni50 alloy by increasing cooling rate plus annealing

Monophasic Al50Ni50 ribbons were fabricated by melt spinning at circumferential speeds (Sc) of 21 and 42 m/s, and subsequently annealed at various temperatures. The microstructure and corrosion behavior of ribbons were studied through various experimental methods. With increasing Sc, the as-spun and annealed ribbons at 42 m/s show a higher (100) crystal orientation factor F(100), a lower barrier to recrystallization and a higher total film resistance than the counterparts with 21 m/s. The as-spun ribbon at 42 m/s demonstrated a denser and more stable Al2O3 passive film compared to the as-spun and annealed ribbons at 21 m/s. This improvement in passive film can be further enhanced by 700 °C annealing. Therefore, the corrosion resistance of AlNi ribbons can be improved by increasing Sc and additional annealing at an appropriate temperature.

Achieving tailorable nano-crystallization in a fully amorphous Zr50Cu42Al8 alloy

In this work, Zr50Cu42Al8 alloy was rapidly quenched into as-cast rod with nano-glass microstructure and fully amorphous as-spun ribbon, respectively. The different microstructure between the as-cast rod and as-spun ribbon results in the different glass transition, crystallization temperatures and their kinetics. The continuous heating transition (CHT) curves of the as-cast rod and as-spun ribbon derived from their heating rate dependence of onset crystallization temperature imply that the partial nano-crystallization stabilizes the amorphous remainders in the Zr50Cu42Al8 rod when annealed below ∼ 757 K, and give rise to the possibility to obtain nano-crystallization by annealing the fully amorphous ribbons within the temperature interval between the two CHT curves. It is as expected that the ribbons annealed at 730 K for 678 second and at 720 K for 3644 second respectively show similar microstructure and thermal properties to the as-cast rod. The results provide a valid way to achieve tailorable nano-crystallization in the fully amorphous alloys.

Effect of Nb addition and annealing treatment on structural and magnetic properties of Fe–Si–B–P–Cu alloy ribbons

Thermal and magnetic properties of Fe85-xSi2B8P4Cu1Nbx (0 ≤ x ≤ 4) alloy ribbons of different microstructures were systematically investigated. Increase in Nb content raised the first crystallization onset temperature from 646 to 701 K suggesting improved thermal stability. XRD results on the as-spun ribbons also suggested the role of Nb increasing the thermal stability and glass-forming ability by showing fully amorphous patterns for all alloys with Nb addition. However, Nb addition turned out to decrease the saturation magnetic flux density from 1.74 to 1.17 T. To further optimize the properties, annealing treatment was carried out to find the optimized condition as Fe84Si2B8P4Cu1Nb1 processed at 793 K for 10 min resulting in nanocrystalline microstructure with a high saturation magnetic flux density of 2.03 T. Transmission electron microscopy confirmed the formation of nanocrystalline α-Fe phase in the annealed ribbons.

Effect of Mn content on crystallization behaviors and magnetic properties of FeCoNiBMn high-entropy amorphous alloys

FeCoNi-based high-entropy alloys (HEAAs) attracted much attention because of their good thermodynamic stability, mechanical properties and soft magnetic properties. In this paper, Fe22Co22Ni22B34-xMnx (x = 6–22 at%) HEAAs were designed and the effects of Mn on the crystallization behaviors, magnetic performance, and mechanical property were investigated. The crystallization behaviors of the FeCoNiBMn HEAAs are: 1) 12–16 at% Mn: am → am’ + M23B6 → M23B6 + fcc; 2) 18 at% Mn: am → am’ + bcc + M23B6 → bcc + M23B6 → fcc + M23B6; and 3) 20–22 at% Mn: am → am’ + bcc → bcc + M23B6 → fcc + M23B6. Two parameters ΩA and VEC are proposed to predict the primary precipitates of FeCoNi-based HEAAs. All as-spun ribbons exhibit excellent soft magnetic properties with a very low coercivity (Hc) of less than 1.5 A/m and a maximum saturation magnetization (Bs) of 0.82 T. The 14 at% Mn alloy exhibits very low Hc of less than 4 A/m even after complete crystallization. Magnetic properties and Vickers hardness of crystalline ribbons are closely related to crystallization behaviors.

Effects of rare-earth element Y content on the microstructure and properties of quinary Al–Ni–Zr–Co–Y high entropy metallic glasses

A series of quinary (Al1/4Ni1/4Zr1/4Co1/4)100-xYx (x = 16–28 at.%) high entropy metallic glass ribbons were successfully fabricated through the high-speed single roller melt-spinning method. The effects of rare-earth element yttrium content on the microstructure and performances of alloy ribbons were systematically investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), heat treatment, transmission electronic microscopy (TEM), atomic force microscopy (AFM) and electrochemical experiments. The microhardness of metallic ribbons was measured by Vickers hardness tester. Results show that the microstructure of the as-quenched alloy ribbons maintain the glassy state and the average microhardness value of each specimen can reach 488 HV0.1 or above. The surface morphologies of the as-spun ribbon samples exhibit the smooth surface with small roughness value of Ra = 0.115–0.150 nm. In the meantime, with the increase of Y content, the glass transition temperature can be detected in the DSC traces when Y content is over 22 at.%, and the crystallization onset temperature shifts to the lower temperature region, suggesting that the thermal stability of amorphous state in Al–Ni–Zr–Co–Y alloy ribbons has been weakened. The (Al1/4Ni1/4Zr1/4Co1/4)84Y16 alloy ribbons own the highest crystallization onset temperature (∼742 K). Adding appropriate yttrium element can enlarge the super-cooled liquid region and improve the glass-forming ability. In 3.5 wt% NaCl solution, the prepared alloy ribbons can maintain smaller corrosion current densities (∼10−8 A cm−2) than traditional Al-based amorphous alloys, 6061 Al alloy and other common structural steels. The X-ray photoelectron spectrometer results indicate that the passive film of equiatomic alloy ribbons is rich in oxides of Al, Zr, Co, and Y elements, which has excellent resistance to chloride ion attack. On the basis of all experimental results, (Al1/4Ni1/4Zr1/4Co1/4)84Y16 alloy ribbons can optimally combine outstanding corrosion resistance, superior thermal stability, and acceptable microhardness. The above research results lay a solid foundation for the composition development of high-performance high entropy metallic glasses.

Decomposition in Mn50Ni40In10 melt-spun ribbons and its influence on magnetic properties

The phase stability, decomposition and its influence on the martensitic transformation and magnetic properties of magnetic shape memory alloy (MSMA) Mn50Ni40In10 melt-spun ribbons were investigated experimentally and theoretically. As-spun Mn50Ni40In10 was fine single Heusler phase with pronounced martensitic and magnetic transition below room temperature. However, in differential scanning calorimetry measurement an exothermic peak at 690 K and an endothermic peak at 765 K is observed during the heating of as-spun ribbons. The two peaks correspond to the growing of the punctiform precipitates in the grain interiors and the formation of a large amount of grain boundary segregation, respectively. After annealing at 870 K, the ribbon samples decompose into a cubic In-rich phase at grain boundaries and In-poor 7 M−modulate martensitic phase in the matrix. After annealing at 690 K and above, the martensitic transformation below room temperature is strongly weakened. Annealing temperature also has obvious influence on the 5 and 300 K saturation magnetization Ms of Mn50Ni40In10. Theoretical calculations on Mn2Ni1.5In0.5 (Mn50Ni37.5In12.5) give a negative formation energy (-0.11 eV/ f.u.) and a positive decomposition energy (0.22 eV/f.u.), indicating that this alloy can be metastable and tends to decompose into Mn2NiIn cubic phase and NiMn martensite, agreeing with the experimental results qualitatively.

Role of Cr Element in Highly Dense Passivation of Fe-Based Amorphous Alloy.

The effect of the Cr element on the corrosion behavior of as-spun Fe72-xCrxB19.2Si4.8Nb4 ribbons with x = 0, 7.2, 21.6, and 36 in 3.5% NaCl solution were investigated in this work. The results show that the glass formability of the alloys can be increased as Cr content (cCr) is added up to 21.6 at.%. When cCr reaches 36 at.%, some nanocrystals appear in the as-spun ribbon. With increasing cCr content, the corrosion resistances of as-spun Fe-based ribbons are continually improved as well as their hardness properties; during the polarization test, their passive film shows an increase first and then a decrease, with the highest pitting potential as cCr = 7.2 at.%, which is confirmed by an XPS test. The dense passivation film, composed of Cr2O3 and [CrOx(OH)3-2x, nH2O], can reduce the number of corrosion pits on the sample surface due to chloride corrosion and possibly be deteriorated by the overdosed CrFeB phase. This work can help us to design and prepare the highly corrosion-resistant Fe-based alloys.

Magnetic properties of gadolinium and/or dysprosium substituted Sm–Co nanocomposite ribbons

The present study reported the influence of heavy rare-earth elements (Gd and/or Dy) on Sm-Co-based melt-spun ribbons. Microstructure and magnetic properties of Sm-Co-based (Sm1–xRExCo5) ternary and quaternary systems were investigated. The X-ray diffraction, Auger spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses reveal the presence of the 1:5H and 2:17R phases in the as-spun ribbons. A high-temperature magnetic measurement reports a Curie temperature (TC) at ∼825 and ∼869 K in Sm0.6Gd0.4Co5 (ribbon A) and Sm0.6Gd0.3Dy0.1Co5 (ribbon B), respectively. A low-temperature magnetic measurement on Sm0.6Gd0.3Dy0.1Co5 ribbons exhibits a type-2 SR (spin reorientation) behaviour at ∼72 K, which arises due to the presence of the DyCo5 phase. Room temperature magnetic measurements reveal that overall magnetic measurement (OMP) is about 24 and 29.9 for ribbons A and B, respectively. Consequently, the comparative investigations profess that ribbon B shows better magnetic performance due to Dy addition with reduced grain size. This observation indicates that the Gd and Dy substituted Sm–Co magnet can be a potential magnet for high-temperature applications.

A combined study on microstructure, microchemistry and magnetic behavior of (Sm0.12Co0.88)95Hf1B4 nano-composite ribbons by electron microscopy and atom probe tomography

In this work, Hf and B modified ribbon produced by RSP (rapid solidification process) method have been studied to investigate the microstructure, phase formation and magnetic properties of the Sm-Co-based alloy. (Sm0.12Co0.88)95Hf1B4 ribbon has been synthesized and annealed at various temperatures (700 °C, 800 °C & 900 °C) to analyze the effect of temperature on magnetic properties and structure. X-ray diffraction (XRD) phase analysis has confirmed the 1:7 H phase as a significant phase in the as-spun ribbon. A combination of 1:5 H and 2:17 R phases were found in the ribbon annealed at 900 °C due to disorder-order transformation upon heat treatment. The development of ordered structure and grain growth upon annealing at 800 °C and 900 °C have deteriorated the magnetic properties. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analysis also revealed the grain growth and the development of the ordered 2:17 R structure upon annealing. The ribbon annealed at 700 °C showed better magnetic properties, Hc≈ 8.6 kOe, Mr ≈ 49 emu/g and (BH)max≈ 5.63 MGOe with an average grain size of ∼149 ± 5 nm. TC of the as-spun ribbon was found to be ⁓750 °C, and the temperature co-efficient of magnetization (α) and coercivity (β) were about − 0.008 and − 0.161%/°C, respectively. The APT analysis confirmed the fine borides in both as-spun and annealed (700 °C & 900 °C) ribbons.

Microstructure evolution of Pr-doped SmCo4B-based ribbons with improved magnetization

Searching for high-performance permanent magnets is always challenging for modern technological applications. The novel SmCo4B phase has a higher anisotropy field than SmCo5, and this paper disclosed the effect of Pr addition on the phase transformation, microstructure evolution, and magnetism of the multi-element doped Sm1−xPrxCo3.04Fe0.9Cu0.06B ribbons. The results show that Pr addition decreases the amorphous forming ability of the as-spun ribbons. After annealing, Pr addition promotes the growth of strip-like Sm-Co-B grains, and 8 at% Pr addition increases the saturation magnetization and remanence of the Sm-Co-B ribbons by 96.2% and 48.0%, respectively. Pr addition weakens the anisotropy field of the Sm-Co-B phase, resulting in a gradual decrease in coercivity. We revealed the transformation mechanism of strip-like grains during melt-spinning and annealing, found the relationship between phase content, dislocation density, strain, and grain size, and proposed the corresponding microstructure evolution models.

Light activated methylene blue degradation by magnetic Fe80PxC20-x (x = 0, 4, 7 and 13) glassy ribbons

The light activated Methylene Blue (MB) degradation performance and magnetic properties of the Fe80PxC20-x (x = 0, 4, 7 and 13) glassy ribbons are investigated in this work. The structure of the as-spun Fe80C20 ribbons is crystalline state while the as-spun Fe80PxC20-x (x = 4, 7 and 13) ribbons is amorphous state. Under dark condition, the degradation efficiency ηDark for MB decreases gradually with increasing P content (cP) in the ribbons, and the stability of Fe-P bonds is higher than Fe-C bonds in annealing Fe80P4C16 ribbons, indicating that Fe-P bonds release less Fe participating in the Fenton-like reaction; under visible light (VL), the ηVL of ribbons increases firstly and then decreases with increasing cP and the ribbon with x = 4 show the highest ηVL, which is consistent with the changing tendency of soft magnetic property of the present ribbons. This work provides a new insight in designing and applying the FePC amorphous alloys.

Effect of the post annealing cooling rate on the martensitic transformation and the magnetocaloric effect in Ni-Mn-Sn ribbons

We report the modification of the martensitic transformation in Ni-Mn-Sn ribbons by controlling the post annealing cooling rate. Isothermal holding above the order-disorder temperature for 24 h ensured homogeneous grain growth and uniform microstructural features in all the samples. However the atomic order was tailored by varying the cooling rate. The furnace-cooled sample exhibited the highest austenite stabilization and the lowest martensitic transformation temperature of 200.2 K, whereas the air-cooled sample exhibited the highest transformation temperature of 298.5 K. The martensite evolved as ferromagnetic clusters in an anti-ferromagnetic matrix in the samples with high atomic disorder, whereas long-range anti-ferromagnetic co-relations developed in the highly ordered samples. The martensitic transformation in the as-spun ribbons generated a significant magnetocaloric effect and a large entropy change of 4.02 J/kg/K, for a ΔH of 2 T. Furthermore, furnace cooling increased the relative cooling power of the ribbons by 23.3 J/kg over the as-spun specimens.

Microstructure and catalytic properties of rapidly solidified Al-28.5 at% Fe and Al-28.5 at% Co alloys applied for selective hydrogenation of phenylacetylene

The Al 71.5 Fe 28.5 and Al 71.5 Co 28.5 (at.%) melt-spun alloys were examined in terms of microstructure evolution and catalytic response in the semihydrogenation reaction of phenylacetylene to styrene. In the as-spun state ribbons showed a single-phase composition. The Al 71.5 Co 28.5 alloy contained columnar grains of a metastable decagonal quasicrystal, which transformed into hexagonal Al 5 Co 2 and monoclinic Al 3 Co phases after heat treatment at 900 °C. The Al 71.5 Fe 28.5 ribbon had an ordered orthorhombic Al 5 Fe 2 phase structure in both the as-spun and annealed states. The pulverized ribbons revealed considerable catalytic activity for selective hydrogenation of phenylacetylene to styrene. The best results were achieved for the as-spun quasicrystalline Al 71.5 Co 28.5 alloy, showing a conversion rate of above 80% after 2 h reaction time. The selectivity to styrene was 60% for all catalysts. The tested powders retained their phase composition following liquid reaction therefore the proposed materials can be considered for catalytic use. • The Al5Co2 and Al5Fe2 ribbons were prepare by melt spinning methods • Decagonal quasicrystal in the Al5Co2 transforms into Al 5 Co 2 and Al 3 Co after annealing • Ordered orthorhombic Al 5 Fe 2 phase in both the as-spun and the annealed Al5Fe2 ribbons • Catalytic activity of the powdered ribbons in hydrogenation of phenylacetylene • The conversion rate exceeds 80% after 2 h reaction time for quasicrystalline Al5Co2

Annealing and electrochemically activated amorphous ribbons: Surface nanocrystallization and oxidation effects enhanced for oxygen evolution performance

Annealing and cyclic voltammetry (CV) are essential for the activation of amorphous alloy ribbons. Various amorphous alloy ribbons have been activated in the fields of environmental catalysts using either annealing or CV. However, the combination of the two methods for improving the oxygen evolution reaction (OER) performance has rarely been reported. This combination is expected to significantly improve the OER performance of amorphous ribbons. Here, we developed an “annealing +CV-activation” integrated strategy to treat a free-standing NiFeBSiP ribbon, which as an efficient and stable oxygen-evolving electrode. The “annealing +CV-activation” strategy induces the nanocrystallization and oxidation effects on the surface of the NiFeBSiP ribbon. The effects significantly increase the electron transfer ability, the Ni/Fe/P oxidation state and the surface area of the NiFeBSiP ribbon, which consequently leads to enhancing the OER performance. As a result, the treated ribbon exhibits a low overpotential of 269 mV at 10 mA cm−2 and a small Tafel slope of 40.5 mV dec−1, which are much better than the OER performance of the as-spun ribbon. The enhanced OER performance of the NiFeBSiP ribbon demonstrates the significant and promising effect of the “annealing +CV-activation” integrated strategy for designing high-efficiency amorphous alloy ribbons electrocatalysts.

Evolution of microstructure, magneto-structural transformation, and magnetocaloric effect in (Fe72-0.9xNi8-0.1xCo8)Zr7B4Cu1Gax (0 ≤ x ≤ 6 at.%) alloys

We report the evolution of microstructure, magnetic properties, and magnetocaloric effects in a series of (Fe72-0.9xNi8-0.1xCo8)Zr7B4Cu1Gax (0 ≤ x ≤ 6 at.%) alloys. The high temperature X-ray diffraction, calorimetric, and thermomagnetic studies revealed that the α-Fe → γ-Fe transformation occurred in the range of 691–733 K in arc-melted ingots (AMIs), whereas the same occurred at 660–723 K in as-spun ribbons (ASRs). The Curie temperature of γ phase lies in the range of 1126–1140 K and 1106–1126 K for AMIs and ASRs, respectively. Addition of Ga reduces the saturation magnetization and induce nanocrystallization in ASRs. A second-order magnetic transition has been identified in x = 0 ASR using Arrott plot exhibiting magnetic entropy change (|ΔSM|) of 0.973 J/kg.K at TCγ under magnetic field of 0.976 T. The refrigeration capacity of x = 0 and x = 6 ASRs has been estimated to be 12.78 J/kg and 22.98 J/kg, respectively, at 0.976 T.