Reactive Milling Research Articles

Preparation and characterization of MgAl-CuO ternary nanothermite system by arrested reactive milling and its effect on the thermocatalytic decomposition of cellulose nitrate

Nanothermites have been widely employed as an additive in explosive and propellant formulations owing to their high energy release efficiency, fast reaction rate, and enhanced performance. Their properties are closely dependent on the chemical nature of the implemented fuel/oxidizer components as well as the method used for their fabrication. Despite binary nanothermites, which contain one fuel and one oxidizer, being extensively developed and exhibiting interesting results, the exploration of ternary nanothermite systems is still scarce. Herein, MgAl-CuO ternary nanothermite was successfully prepared by the arrested reactive milling method (ARM). The product was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser granulometry, revealing that the particle size distributions of the powder samples obtained with pre-milled ingredients tend to shift to smaller sizes. On the other hand, composite films based on cellulose nitrate (NC) at different ratios of the nanothermite (5 %, 10 %, 15 %, and 20 %) were accordingly prepared and were fully characterized using different analytical techniques such as Fourier transform infrared (FTIR) and Raman spectroscopies, XRD, SEM, oxygen bomb calorimeter, and differential scanning calorimetry (DSC). The thermal decomposition behavior of the obtained composites was further investigated using isoconversional kinetic analysis to assess the catalytic effect of the ternary nanothermite on the thermal behavior of cellulose nitrate (CN), whereas the energetic performances of the obtained nanocomposites were predicted by EXPLO5 V6.04 software. The obtained results have shown that MgAl-CuO nanothermite has a minor influence on the thermal decomposition temperature of the studied composites, while a noticeable decrease in the activation energy has been obtained for the different composites, demonstrating the catalytic effect of the nanothermite. It was revealed that NC composite supplemented with 5 % MgAl-CuO displayed the greatest heat of reaction and better energetic performance.

Improving hydrogen storage thermodynamics and kinetics of Ce-Mg-Ni-based alloy by mechanical milling with TiF3

Mg-based hydrides are too stable and the kinetics of hydrogen absorption and desorption is not satisfactory. An efficient way to improve these shortcomings is to employ reactive ball milling to synthesize the nanocomposite materials of Mg and additives. In this experiment, TiF3 was selected as an additive, and the mechanical milling method was employed to prepare the experimental alloys. The alloys used in this experiment were the as-cast Ce5Mg85Ni10, as-milled Ce5Mg85Ni10 and Ce5Mg85Ni10 + 3 wt.% TiF3. The phase transformation, structural evolution, isothermal and non-isothermal hydrogenation and dehydrogenation performances of the alloys were inspected by XRD, SEM, TEM, Sievert apparatus, DSC and TGA. It revealed that nanocrystalline appeared in the as-milled samples. Compared with the as-cast alloy, ball milling made the particle dimension and grain size decrease dramatically and the defect density increase significantly. The addition of TiF3 made the surface of ball milling alloy particles markedly coarser and more irregular. Ball milling and adding TiF3 distinctly improved the activation and kinetics of the alloys. Moreover, ball milling along with TiF3 can decrease the onset dehydrogenation temperature of Mg-based hydrides and slightly ameliorate their thermodynamics.

New horizon in mechanochemistry—high-temperature, high-pressure mechanical synthesis in a planetary ball mill—with magnesium hydride synthesis as an example

A new route of materials synthesis, namely, high-temperature, high-pressure reactive planetary ball milling (HTPRM), is presented. HTPRM allows for the mechanosynthesis of materials at fully controlled temperatures of up to 450 °C and pressures of up to 100 bar of hydrogen. As an example of this application, a successful synthesis of magnesium hydride is presented. The synthesis was performed at controlled temperatures (room temperature (RT), 100, 150, 200, 250, 300, and 325 °C) while milling in a planetary ball mill under hydrogen pressure (>50 bar). Very mild milling conditions (250 rpm) were applied for a total milling time of 2 h, and a milling vial with a relatively small diameter (φ = 53 mm, V = ∼0.06 dm3) was used. The effect of different temperatures on the synthesis kinetics and outcome were examined. The particle morphology, phase composition, reaction yield, and particle size were measured and analysed by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry (DSC) techniques. The obtained results showed that increasing the temperature of the process significantly improved the reaction rate, which suggested the great potential of this technique for the mechanochemical synthesis of materials.

Enhancement of the Hydrogenation and Dehydrogenation Characteristics of Mg by Adding Small Amounts of Nickel and Titanium

We compared the hydrogenation and dehydrogenation properties of Mg-based alloys to which small amounts of transition elements (Ni and Ti), halides (TaF5 and VCl3), and complex hydrides (LiBH4 and NaAlH4) were added through grinding in a hydrogen atmosphere (reactive milling). Mg-1.25Ni-1.25Ti is one of the samples compared, having a composition of 97.5 wt.% Mg + 1.25 wt.% Ni and 1.25 wt.% Ti. Even though Mg-1.25Ni-1.25Ti did not have the highest initial hydrogenation rate, it had the largest quantities of hydrogen absorbed and released for 60 min and the highest initial dehydrogenation rate. In addition, Mg-1.25Ni-1.25Ti did not show the incubation period in the dehydrogenation. We thus investigated the hydrogenation and dehydrogenation properties of Mg-1.25Ni-1.25Ti in more detail. Activated Mg-1.25Ni-1.25Ti absorbed 5.91 wt.% H in 12 bar H2 and released 5.80 wt.% H in 1.0 bar H2 at 593 K for 60 min at n = 3. For 5 wt.% hydrogen absorption by Mg-1.25Ni-1.25Ti, 18.7 min was required at 593 K in 12 bar H2 at n = 3. Although only small amounts of Ni and Ti were added, the hydrogenation and dehydrogenation properties of Mg were greatly improved. Ni and Ti-added Mg had a higher initial dehydrogenation rate and a larger Hd (60 min) than only Ni-added Mg, suggesting that the TiH1.924 and NiTi formed in Mg-1.25Ni-1.25Ti play roles in the increases in the initial dehydrogenation rate and Hd (60 min), probably acting as active sites for the nucleation of the Mg-H solid solution phase.

Synthesis, characterization and first hydrogen absorption/desorption of the Mg35Al15Ti25V10Zn15 high entropy alloy

In this work, a novel Mg-containing high entropy alloy (HEA), namely Mg35Al15Ti25V10Zn15, was synthesized, characterized, and the phases formed after synthesis and after first hydrogen absorption/desorption were analyzed. The alloy composition was conceptualized aiming at increasing the atomic fraction of lightweight elements (35 at.% Mg and 15 at.% Al) to increase its gravimetric hydrogen storage capacity. Ti and V were selected to increase the hydrogen affinity of the alloy. Finally, Zn was selected as an alloying element because of its negative enthalpy of mixing with Mg, which could favor the formation of solid solution and avoid Mg segregation. The Mg35Al15Ti25V10Zn15 HEA was synthesized by high-energy ball milling (HEBM) in two different routes: under argon atmosphere (mechanical alloying – MA) and under hydrogen pressure (reactive milling – RM). The sample produced by MA was composed of a body-centered cubic (BCC) phase with an amount of unmixed Mg. When hydrogenated at 375 °C and under 4.0 MPa of H2, the MA sample absorbed about 2.5 wt% of H2 by forming a mixture of MgH2, a face-centered cubic (FCC) hydride, a body-centered tetragonal (BCT) phase and MgZn2. The desorption sequence upon heating was investigated and it was shown that the MgH2 is the first to desorb. The sequence of desorption is completed by the decomposition of the FCC hydride and BCT phase leading to the formation of the BCC phase. On the other hand, the alloy produced by RM was composed of a mixture of an FCC hydride and MgH2. During desorption upon heating, the MgH2 is also the first to desorb. At lower temperatures (below 350 °C), the FCC hydride decomposes partially forming the BCT phase. At higher temperatures, both FCC hydride and BCT phase decomposes forming the BCC phase. The desorption capacity of the RM sample was 2.75 wt% H2.

Hydrogen Storage Behavior and Performance of Multiple Cold-Rolled MgH2/Nb2O5 Nanocomposite Powders

The global interest in MgH2 is due to the natural availability of Mg and its capacity to retain hydrogen at a concentration of up to 7.60 wt.%. Despite its appealing characteristics and ease of production on an industrial scale at ambient temperature using the reactive ball milling (RBM) technique, MgH2 is a highly stable chemical with sluggish hydrogenation and dehydrogenation rates below 300 °C. Among the different methods used to improve the hydrogenation/dehydrogenation kinetic behavior of MgH2, mechanical treatment and/or catalysis are regarded to be the most effective methods. The purpose of this research was to explore the effectiveness of several cold rolling (CR) stages on the hydrogenation properties of recycled magnesium rods, as well as the effect of the resulting RBM on the final product. For this process, the as-received waste Mg-rods were firstly cold-rolled 200 times and then remilled under H2 atmosphere for 100 h. The as-RBM powders were then cold-rolled for 100 passes and then ball-milled with 10 and 15 wt.% Nb2O5 powders for 50 h. The results showed that when the materials were subjected to different types of defects (dislocations, stacking faults, and twining) generated by CR and RBM, their gas absorption/desorption kinetics were improved. This was indexed by their ability to achieve a long cycle lifetime at lower temperatures when compared with the as-received materials. The powders were further improved in terms of kinetics and decomposition temperature upon RBM with Nb2O5 for 50 h. The nanocomposite MgH2/10 wt.% and 15 wt.% Nb2O5 exhibit good hydrogen storage capabilities at a comparatively low temperature (225 °C) with a long cycle life that extended from 110 h to 170 h, without serious degradation in storage capacity and kinetics.

Chloride-Derived Bimetallic Cu-Fe Nanoparticles for High-Selective Nitrate-to-Ammonia Electrochemical Catalysis

Cu-based bimetallic materials have been widely reported as efficient catalysts for electrocatalytic nitrate reduction. However, the faradaic efficiency and selectivity are still far from satisfactory. Herein, Cu-Fe bimetallic nanoalloys with adjustable Cu/Fe ratios are successfully prepared through a reactive mechanical milling approach with CuCl2, FeCl3 and Na as the starting materials. The optimized Cu3Fe exhibits excellent nitrate conversion efficiency of 81.1% and 70.3% ammonia selectivity at −0.7 V vs. RHE within 6 h under 0.1 M Na2SO4 and 100 ppm NO3−. The Fe-introduction-induced upshift of the d-band center is identified to be beneficial for promoting nitrate adsorption on Cu3Fe. Moreover, favorable H generation under the assistance of Fe could effectively accelerate the stepwise hydrogenation during electrocatalytic nitrate reduction, resulting in significantly improved NH4+ selectivity. This work supplies valuable insights for the rational design of transition-metal-based bimetallic catalysts for electrocatalytic nitrate reduction.

Hierarchical conformal coating enables highly stable microparticle Si anodes for advanced Li-ion batteries

Microsized silicon powders have great potential for high capacity anode materials in next-generation lithium ion batteries, because of the high gravimetric and volumetric energy densities, ease of mass production and low costs. However, large volume change and consequently rapid capacity fading upon lithiation and delithiation prevent its practical applications. Herein, we demonstrate an effective hierarchical conformal coating strategy for high-performance microsized Si anodes. The Si-based composites consist of an amorphous Li-Si-O inner coating layer and a graphene outer encapsulation layer, which are prepared by coupling reactive milling with electrostatic self-assembly. This unique hierarchical conformal coating structure not only strengthens the mechanical property (31.8 GPa for the elastic modulus) and promotes the ionic diffusion (2.03 × 10−10 cm2 s−1) of Si anode, but also effectively stabilizes the electrode/electrolyte interfaces and increases the electronic conductivity. As a result, a high reversible capacity (1450 mA⋅h g−1 at 0.1 A g−1), good cycling stability (97.7% of capacity retention from the 2nd to the 310th cycle at 0.5 A g−1), and high rate capability (703 mA⋅h g−1 at 5 A g−1) have been successfully achieved. These findings provide new insights into the improvement of electrochemical properties of microsized Si composite anodes for high-performance Li-ion batteries.

Effects of Preparation Procedures and Porosity on Thermoelectric Bulk Samples of Cu2SnS3 (CTS).

The thermoelectric behavior and stability of Cu2SnS3 (CTS) has been investigated in relation to different preparations and sintering conditions, leading to different microstructures and porosities. The studied system is CTS in its cubic polymorph, produced in powder form via a bottom-up approach based on high-energy reactive milling. The as-milled powder was sintered in two batches with different synthesis conditions to produce bulk CTS samples: manual cold pressing followed by traditional sintering (TS), or open die pressing (ODP). Despite the significant differences in densities, ~75% and ~90% of the theoretical density for TS and ODP, respectively, we observed no significant difference in electrical transport. The stable, best performing TS samples reached zT ~0.45, above 700 K, whereas zT reached ~0.34 for the best performing ODP in the same conditions. The higher zT of the TS sintered sample is due to the ultra-low thermal conductivity (κ ~0.3–0.2 W/mK), three-fold lower than ODP in the entire measured temperature range. The effect of porosity and production conditions on the transport properties is highlighted, which could pave the way to produce high-performing TE materials.

Soft Magnetic Nanocrystalline Ni-Fe-X-Y and MeFe2O4 Powders Obtained by Mechanosynthesis

"The soft magnetic nanocrystalline powders, alloys (Ni3Fe, 79Ni16Fe5Mo, 77Ni14Fe5Cu4Mo, wt. %) and zinc ferrite, were obtained by dry and wet mechanical alloying and reactive milling, followed by different heat treatments. The powders were characterised by X-ray diffraction, scanning electron microscopy, X-ray microanalysis, differential scanning calorimetry, thermomagnetic and magnetic measurements. The X-ray diffraction shown the progressive new phases formation. The crystallite size is between 18-7 nm depending on materials and milling conditions. The particle size is smaller for wet-mechanical alloying comparing with dry-milling. The thermomagnetic measurement shown the Curie temperature of the alloys. The spontaneous magnetisation of the wet-milled and annealed samples is higher than of the molten alloys. Keywords: mechanical alloying; Ni-Fe-X-Y alloys; soft ferrite; magnetisation; XRD; DSC. "

Magnesium-based complex hydride mixtures synthesized from stainless steel and magnesium hydride with subambient temperature hydrogen absorption capability

Here, we present the results of the synthesis of a complex hydride previously described as Mg2(Fe, Cr, Ni)Hx formed during the reactive ball milling process of AISI 316 L stainless steel (316 L SS) and magnesium hydride under hydrogen pressure. The evolution of powder morphology and phase composition with milling time is presented. The reaction of magnesium hydride with 316 L steel was found to proceed faster than in case of the reaction of reference mixture containing pure iron. Obtained material was found to possess cubic K2PtCl6-structure with slightly different lattice parameter as compared to Mg2FeH6. The hydrogen content of the obtained samples was found to be around 4 wt%. The mixture that resulted from the decomposition of this synthesized sample was able to absorb around 1% of hydrogen even at − 50 ℃ via the formation of magnesium hydride.

Just shake or stir. About the simplest solution for the activation and hydrogenation of an FeTi hydrogen storage alloy

Despite many years having passed since it was discovered, FeTi alloys remain one of the most important low-temperature hydrogen storage alloys due to its high capacity, characteristics and low price. However, the main technological issue is its initial activation, which is usually conducted at relatively high temperature and pressure. This paper is the first to show that the complicated process can be replaced by intense movement of the powder or even chunks of alloy under hydrogen pressure without any additional grinding media. The newly discovered process, named self-shearing reactive milling (SSRM), leads to the full hydrogenation of FeTi alloys. The wear of particles, which is caused by their movement, causes the exposure of a fresh active alloy surface that is active enough to absorb hydrogen without any thermal treatment or evacuation. The resultant material, despite simply being strongly stirred, evolves from large chunks to an extremally fine spongy structure containing particle with sizes of tens of nanometers that combine to form large agglomerates. This result is an enormous improvement for the potential use of FeTi alloys and all other AB-type alloys in commercial applications by extraordinarily simplifying hydrogen storage vessels, which will not have to withstand high-temperature and pressure activation.

Room temperature conversion of Mg to MgH2 assisted by low fractions of additives

In recent works, it was noticed that Mg/MgH2 mixed with additives by high energy ball milling allows temperature reductions of H2 absorption/desorption without necessarily changing thermodynamic properties. Thus, the objective of this work was to investigate which additives, mixed in low fractions with MgH2 powder would act as efficient hydrogen absorption/desorption catalysts at low temperatures, mainly at room temperature (RT). MgH2 mixtures with 2 mol% additives (Fe, Nb2O5, TiAl and TiFe) were prepared by high energy reactive ball milling (RM). MgH2–TiFe mixture showed the best results, both during desorption at 330 °C and absorption at RT. The hydrogen absorption was ≈ 2.67 wt% H2 in 1 h and ≈ 4.44 wt% H2 in 16 h (40% and 67% of maximum theoretical capacity, respectively). The MgH2–TiFe superior performance was attributed to the hydrogen attraction by the created high energy interfaces and strong TiFe catalytic action facilitating the H2 flow during Mg/MgH2 reactions.

Titanium-boron reactive composite powders with variable morphology prepared by arrested reactive milling

Powders with compositions Ti·B and Ti·2B with components mixed on the nanoscale were prepared by arrested reactive milling as high energy density fuels. A planetary mill with hardened steel vials and milling media were used. Powders with irregular and spherical particle shapes were prepared. Spherical powders were prepared milling starting boron and titanium in presence of two immiscible liquids, hexane and acetonitrile, serving as process control agents. Prepared powders were characterized using electron microscopy, x-ray powder diffraction, nitrogen adsorption, thermal analysis, and ignition measurements. Average volumetric particle sizes for spherical powders could be controlled in a range from tens to hundreds of µm selecting milling conditions. All spherical powders were found to be porous, unlike reference irregularly shaped composite powders. Despite porosity, spherical powders packed at nearly the same bulk density as irregularly shaped powders. It was also observed that milling led to formation of poorly crystalline TiB in all milled materials. The amount of observed TiB as well as contamination by Fe from the milling tools increased at greater milling dose (e.g., energy transferred to the powders being milled from the milling tools). Substantial portion of the prepared composite materials (more than half) was amorphous. The amount of the formed TiB did not correlate with the reactivity of the prepared materials. All composite materials exhibited exothermic reactions at low temperatures when heated in both inert and oxidizing environments. The exothermic reactions were always stronger for spherical powders. Oxidation for spherical powders started sooner (at lower temperatures) compared to the irregularly shaped composites or to elemental metal fuels, boron and titanium. Similarly, spherical powders ignited at ca. 500 °C, a lower temperature than ignition of irregularly shaped powders with the same compositions.

Improvement in the Hydrogenation and Dehydrogenation Features of Mg by Milling in Hydrogen with Vanadium Chloride

VCl3 (vanadium (III) chloride) was selected as an additive to Mg to increase the hydrogenation and dehydrogenation rates and the hydrogen storage capacity of Mg. Instead of MgH2, Mg was used as a starting material since Mg is cheaper than MgH2. Samples with a composition of 95 wt% Mg + 5 wt% VCl3 (named Mg-5VCl3) were prepared by milling in hydrogen atmosphere (reactive milling). In the first cycle (n=1), Mg-5VCl3 absorbed 5.38 wt% H for 5 min and 5.95 wt% H for 60 min at 573 K in 12 bar hydrogen. The activation of Mg-5VCl3 was completed after three hydrogenation-dehydrogenation cycles. During milling in hydrogen, β-MgH2 and γ-MgH2 were produced. The formed β-MgH2 and γ-MgH2 are considered to have made the effects of reactive milling stronger as β-MgH2 and γ-MgH2 themselves were being pulverized. The introduced defects and the interfaces between the Mg and the phases formed during the reactive milling and during hydrogenation-dehydrogenation cycling are believed to serve as heterogeneous active nucleation sites for MgH2 and Mg-H solid solution. The phases generated during hydrogenation-dehydrognation cycling are also believed to prevent the particles from coalescing during hydrogenation-dehydrognation cycling.

Improvement in the Hydrogenation and Dehydrogenation Features of Mg by Milling in Hydrogen with Vanadium Chloride

VCl3 (vanadium (III) chloride) was selected as an additive to Mg to increase the hydrogenation and dehydrogenation rates and the hydrogen storage capacity of Mg. Instead of MgH2, Mg was used as a starting material since Mg is cheaper than MgH2. Samples with a composition of 95 wt% Mg + 5 wt% VCl3 (named Mg-5VCl3) were prepared by milling in hydrogen atmosphere (reactive milling). In the first cycle (n=1), Mg-5VCl3 absorbed 5.38 wt% H for 5 min and 5.95 wt% H for 60 min at 573 K in 12 bar hydrogen. The activation of Mg-5VCl3 was completed after three hydrogenation-dehydrogenation cycles. During milling in hydrogen, β-MgH2 and γ-MgH2 were produced. The formed β-MgH2 and γ-MgH2 are considered to have made the effects of reactive milling stronger as β-MgH2 and γ-MgH2 themselves were being pulverized. The introduced defects and the interfaces between the Mg and the phases formed during the reactive milling and during hydrogenation-dehydrogenation cycling are believed to serve as heterogeneous active nucleation sites for MgH2 and Mg-H solid solution. The phases generated during hydrogenation-dehydrognation cycling are also believed to prevent the particles from coalescing during hydrogenation-dehydrognation cycling.

Improvement in Hydriding and Dehydriding Features of Mg-TaF5-VCl3 Alloy by Adding Ni and x wt% MgH2 (x = 1, 5, and 10) Together with TaF5 and VCl3.

In our previous work, TaF5 and VCl3 were added to Mg, leading to the preparation of samples with good hydriding and dehydriding properties. In this work, Ni was added together with TaF5 and VCl3 to increase the reaction rates with hydrogen and the hydrogen-storage capacity of Mg. The addition of Ni together with TaF5 and VCl3 improved the hydriding and dehydriding properties of the TaF5 and VCl3-added Mg. MgH2 was also added with Ni, TaF5, and VCl3 and Mg-x wt% MgH2-1.25 wt% Ni-1.25 wt% TaF5-1.25 wt% VCl3 (x = 0, 1, 5, and 10) were prepared by reactive mechanical milling. The addition of MgH2 decreased the particle size, lowered the temperature at which hydrogen begins to release rapidly, and increased the hydriding and dehydriding rates for the first 5 min. Adding 1 and 5 wt% MgH2 increased the quantity of hydrogen absorbed for 60 min, Ha (60 min), and the quantity of hydrogen released for 60 min, Hd (60 min). The addition of MgH2 improved the hydriding–dehydriding cycling performance. Among the samples, the sample with x = 5 had the highest hydriding and dehydriding rates for the first 5 min and the best cycling performance, with an effective hydrogen-storage capacity of 6.65 wt%.

Si-TiN alloy anode materials prepared by reactive N2 gas milling: thermal stability and electrochemistry in Li-cells

Si-TiN alloys were synthesized through a novel N2 gas milling method and a conventional inert gas milling approach. Thermal stability of these two kinds of Si-TiN alloys and their electrochemistry as negative electrodes in Li-ion cells were evaluated before and after heating. Si70(TiN)30 prepared by N2 gas milling was found to have high temperature tolerance, evidenced by low crystallization and fine grain structure after heat treatment. The Si70(TiN)30 (N2) alloy after heat treatment shows resistance to Li15Si4 formation during electrochemical lithium insertion, which is presumably due to its fine grain structure. Si70(TiN)30 (N2) was further modified by carbon coating at 800°C, resulting in a high capacity retention after 50 cycles of 94%, while achieving a large reversible volumetric capacity of 1490 Ah/L.

Si(CO)y Negative Electrodes for Li-Ion Batteries

Si(CO)y (0 ≤ y ≤ 0.43) alloys were synthesized by reactive gas milling silicon in CO2 at room temperature. Silicon reacts with CO2 rapidly during milling, incorporating C and O in a 1:1 ratio to form alloys consisting of Si nanograins dispersed in an amorphous Si–O–C matrix. The capacity behavior of these alloys suggests the formation of inactive SiC and Li4SiO4 during the first lithiation. This implies that such alloys can have significantly greater initial coulombic efficiency (ICE) than SiOx at any given gravimetric or volumetric capacity.

Effect of milling time on microstructure of cobalt ferrites synthesized by mechanical alloying

Purpose: of this paper is to determine the effect of manufacturing conditions, especially milling time, on the microstructure and phase composition of CoFe2O4 cobalt ferrite. Design/methodology/approach: Cobalt ferrite (CoFe2O4) has been synthesised from a stoichiometric mixture of CoCo3 and α-Fe2O3 powders in a high energy planetary mill. Annealing at 1000°C for 6 hours after milling was used to improve the solid-state reaction. Calcinated samples were analysed by X-ray diffraction (XRD), and transmission electron microscopy (TEM). The relationship between the milling time of powders, their microstructure, as well as their properties were evaluated. Particles size distribution and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) examination were also made. Findings: CoFe2O4 ferrites were successfully synthesized by mechanical alloying of α-Fe2O3 and CoCO3 powders. The powder particles had undergone morphological changes with the increasing milling time. However, the milling time does not affect the ferrite formation rate. It is expected that the improvement of fabrication parameters can further enhance the properties of cobalt ferrite presented in this work. Research limitations/implications: Contribute to research on the structure and properties of cobalt ferrites manufactured by mechanical alloying. Practical implications: The reactive milling and subsequently annealing is an efficient route to synthesise cobalt ferrite powder. However, using steel milling equipment risks powder contamination with iron and chromium from the vials and balls. Originality/value: The results of the experimental research of the developed ferrite materials served as the basis for determining material properties and for further investigation.