The XRD patterns of the materials with 0.7–6.0 mol.% of CeO 2 in Mg before and after hydrogenation are shown in Fig. 1.It can be seen that after ball milling, the diffraction peaks of Mg (Fig. 1 a) become relatively weaker and broader with the increase of CeO 2 from 0.7 mol.% to 6.0 mol.%, while the intensity of CeO 2 becomes relatively …
Ball milling is a commonly used mechanical method for the preparation of metal hydrides, which can improve the hydrogen storage properties of magnesium alloys by reducing the particle size and increasing the surface area, thus facilitating hydrogen absorption and desorption [9].The development of magnesium alloys through ball …
Al and Mg composite powders were made from the raw powders using mechanical ball milling. Fig. 2 shows irregular particle shapes with several size distributions for the three composite powders. In Fig. 2 (a–c), it can be observed that the amount of spherical particles increased as the Mg content increased. The Al particles in …
Time-resolved studies of the hydrogenation process have been performed thus allowing to uncover kinetics and mechanism of the Mg–hydrogen interactions in presence of various types of carbon during the High energy ball milling. HRBM of magnesium with minor amounts of additives (⩾1 wt%) of different carbon materials, …
Atomized 2009Al alloy (Al-4 wt% Cu-1.5 wt% Mg) powders with approximately 10 µm diameters (Fig. 1 a), and multi-walled CNTs (Fig. 1 b and c) with diameters ranging from 15 to 30 nm and the lengths of 1–5 µm were chosen as the raw materials.For milling process, planetary ball milling equipment (TENCAN, XQM …
In this letter we address the problem of air contamination in high energy milling and cold rolling of magnesium hydride. We found that for short milling time (30 min) milling under argon or air leads to the same crystal structure and same hydrogen sorption behaviour.In the case of the cold rolled sample, the hydrogen sorption …
By ball milling the magnesium powder together with different additives the hydrolysis reaction properties of the magnesium powder can be significantly improved. First, the grinding ball's high speed movement during the ball milling process can continuously impact magnesium powder particles. This can make the morphology of …
Ball milling is a commonly used mechanical method for the preparation of metal hydrides, which can improve the hydrogen storage properties of magnesium …
In this paper, Cu9Al4, which has no hydrogen storage capacity, was added to magnesium by high energy ball milling to prepare Mg-10 wt.% Cu9Al4 composites. The effects of ball milling time on the microstructure and hydrogen storage properties were examined in detail by varying the ball milling time to 60, 120, 180, 240, and 300 min. …
The mechanical milling of MgH 2 powders with 5 at.% M metal leads to the formation of a parent MH x metal hydride [1]. Fig. 2 shows the XRD spectra of the powder MgH 2 +5 at.% Ti for several milling times. The magnesium hydride is of the rutile type crystal structure β-MgH 2.All along the milling procedure the diffraction peak intensities …
A preliminary study showed that the high-energy ball milling of metallic magnesium powder exposed to environmental conditions leads to the formation of pure MgO [44], where the fastest way that was demonstrated to produce pure MgO is ball-milling the exposed magnesium for 160 min using WC as a milling material, with a …
In this context, the use of ball milling techniques 16,17,18,19,20,21,22,23,24 for the solvent-free preparation of Grignard reagents via reactions between aryl halides and magnesium metal has been ...
A kind of by ball milling magnesium powder with the method for graphite oxide macroscopic preparation of graphene, graphite oxide and the magnesium powder mixing and ball milling of preparation are obtained Graphene, present invention process condition is simple, magnanimity can be realized prepare, the Graphene of preparation can have …
3.1 Evolution of the Phase and Microstructure. Figure 1 is the XRD pattern of Nd 5 Mg 41 Ni alloy with different ball milling time and the XRD pattern of as-cast, saturated hydrogen absorption, and fully dehydrogenated. The milling time was 5 h, 10 h, 15 h, and 20 h, respectively. By comparing the XRD pattern of the ball-milled Nd 5 Mg 41 Ni alloy with …
The lignite-derived carbon from self-protection pyrolysis was employed to balance the fracturing and cold-welding of magnesium during ball milling. Particle size …
Porous magnesium/carbon nanofiber composites were produced using a powder metallurgic method to study the effect of ball milling time on their microstructure and hardness. Three ball milling times (240 min, 320 min, and 480 min) and two carbon nanofiber concentrations (0.05% and 1%) were utilized in the production of these porous …
The hydrogen sorption kinetics of magnesium hydride can be improved by ball milling. The ball-milled magnesium hydride could fully absorb at 573 K and desorb at 623 K within a few minutes, which is 5 times faster than that of unmilled MgH 2. The improved kinetics is explained by the defects introduced during ball milling, the small …
Polycrystalline magnesium consisted of pure elemental magnesium powder (99.8 wt.% purity, −325 mesh, Alfa Aesar). Nanocrystalline magnesium was prepared by high energy ball milling of polycrystalline Mg powder. The ball milling was performed with a SPEX 8000 ball mill. The vial and the balls were made in stainless steel.
The ball milling products were identified by XRD (as shown in Fig. 1). Fig. 1 displays the phase transformation of the Mg-Mg 2 Si-NaBO 2 ∙2H 2 O mixtures during ball milling. The formation of NaBH 4 was confirmed by the peaks at 2θ = 28.9°, 41.4°, 49.0° and 51.3°. The presence of MgO was verified by the appearance of diffraction peaks …
Nanocrystalline magnesium ferrite is synthesized by high-energy ball milling. The formation of nanocrystalline ferrite phase is observed after 3 h of milling and its content increases with milling time.The structural and microstructural evolution of the nanophase have been studied by X-ray powder diffraction and the Rietveld method.
Ball milling breaks down the magnesium hydride particles and induces stresses and defects in the structure [4], [5]. The ball milling treatment increases the hydriding kinetics by approximately a factor of 10. As ball milling breaks down the particles, a higher surface area is present for hydrogen to enter the particles.
Abstract. The influence of the high-energy ball milling on the corrosion behavior of magnesium in aqueous media has been investigated through …
a, Overview of chemical and physical activation methods for raw-form magnesium(0).b, Degradation of toxic chloroarene materials using magnesium(0) and …
Table 1 summarises the chemical composition and the major impurities of as-received magnesium aluminate powder and the powder prepared by high energy milling for 10 h, measured using XRF technique. Although the powder composition remains essentially unchanged after the milling process, limited amounts of impurities such as …
Theoretically ball milling can break the oxide layer on magnesium powder and provide fresh surfaces, however, because of the limitation of the vacuum degree of the ball-milled vial, nanocrystalline Mg always interacts with oxygen during ball milling, especially during hydrogen absorption/desorption cycles, which lead to the oxygen layer reform .
The milling media were stainless steel balls with diameters of 3, 6, 10 and 20 mm, and the number of them were 500, 20, 2 and 2, respectively. In addition, milling parameters were regulated. The milling conditions used in present paper were milling time of 6.0 h, speed of 400 r min −1, ball to sample weight ratio of 29:1. To prevent samples ...
The powder metallurgy (PM) processes have undergone significant advancements with the use of ball milling (BM), facilitating the production of UFG alloys and composites exhibiting improved microstructural and mechanical features [[1], [2], [3]].In general, the deformation process of Al powders during BM can be characterized as …
But it only result in mechanical mixing of B particles, and the interfacial bonding between B particles and magnesium matrix was very weak owing to low wettability. As a result, it failed to increase the mechanical properties of magnesium alloys. High-energy ball milling (HEBM) is a powder preparation technology that involves ultra …
To prepare nanosized magnesium which reversibly absorbs hydrogen with high capacity even under mild conditions, high energy ball-milling of Mg or MgH 2 with benzene or cyclohexane as additives have been studied. In ball-milling of Mg or MgH 2, the use of the organic additives is very crucial in determining the characteristics of the …
Ball-milling parameters: The ball-milling parameters, such as the milling time, milling speed, and ball-to-powder ratio, should be adjusted to obtain the optimal particle size, surface area, and microstructure of the magnesium-based materials . Longer milling times can lead to a greater reduction in particle size and an increase in surface area ...
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