High-energy Ball Milling Research Articles

Effect of Milling Time and Reinforcement Volume Fraction on Microstructure and Mechanical Properties of SiCp-Reinforced AA2017 Composite Powder Produced by High-Energy Ball Milling.

The influence of milling time and volume fraction of reinforcement on the morphology, microstructure, and mechanical behaviors of SiCp-reinforced AA2017 composite powder produced by high-energy ball milling (HEBM) was investigated. AA2017 + SiCp composite powder with different amounts of SiC particles (5, 10, and 15 vol%) was successfully prepared from gas-atomized AA2017 aluminum alloy powder with a particle size of <100 μm and silicon carbide (SiC) powder particles with an average particle size of <1 μm. An optical microscope (OM), X-ray diffraction (XRD), and scanning electron microscope (SEM) were utilized to characterize the microstructure of the milled composite powder at different milling periods. The results indicated that the SiC particles were homogeneously distributed in the AA2017 matrix after 5 h of HEBM time. The morphology of the particles transformed from a laminar to a nearly spherical shape, and the size of the milled powder particles reduced with increasing the content of SiC particles. The XRD analysis was carried out to characterize the phase constituents, crystallite size, and lattice strain of the composite powders at different milling periods. It was found that with increasing milling time and SiC volume fraction, the crystallite size of the aluminum alloy matrix decreased while the lattice strain increased. The average crystallite sizes were reduced from >300 nm to 68 nm, 64 nm, and 64 nm after 5 h of milling, corresponding to SiC contents of 5, 10, and 15 vol%, respectively. As a result, the lattice strain increased from 0.15% to 0.5%, which is due to significant plastic deformation during the ball milling process. XRD results showed a rapid decrease in crystallite size during the early milling phase, and the minimum grain size was achieved at a higher volume fraction of SiC particles. Microhardness tests revealed that the milling time has a greater influence on the hardness than the amount of SiC reinforcements. Therefore, the composite powder milled for 5 h showed an average microhardness three times higher than that of the unmilled powder particles.

Enhancing RDX Thermal Decomposition in Al@RDX Composites with Co Transition Metal Interfacial Layer

In this study, an Al/Co@RDX composite was meticulously prepared through a combination of planetary high-energy ball-milling and a spray-drying technique. The thermal reactivity of these Al/Co@RDX composites was comprehensively investigated and compared using the TG/DSC technique. It is shown that the initial decomposition temperature of RDX in the DSC curve was decreased by 26.3 °C in the presence of Al/Co, which could be attributed to the nano-sized Co transition metal catalyzing the decomposition reaction of nitrogen oxides in RDX decomposition products. The decomposition peak temperature of RDX and the heat released by the thermal decomposition of RDX in the Al/Co@RDX composite were decreased by 26.3 °C and increased by 74.5 J·g−1, respectively, in comparison with those of pure RDX. The types of major gaseous products released from Al/Co@RDX were found to be identical to those of pure RDX, encompassing N2O, CH2O, CO2 and HCN. However, the concentrations of those gaseous products for Al/Co@RDX were higher than those observed for pure RDX, which may owe to the fact that the Al/Co composite can interact with the –CH2 and –NO2 within RDX molecules, which leads to the weakening of the C-N and N-N bonds. In addition, the decomposition of RDX in the Al/Co@RDX composite was observed as a one-step process with an apparent activation energy (Ea) of 115.6 kJ·cm−3. The decomposition mechanism of the RDX in the Al/Co@RDX composite was identified to follow the chain scission model (L2), whereas the two-step decomposition physical models observed for pure RDX were found to closely resemble the L2 and autocatalytic models.

Highly sintering-resistant iron oxide with a hetero-oxide shell for chemical looping water splitting

Chemical looping water splitting is a promising technology that couples carbonaceous fuel oxidation to produce H2 with inherent CO2 separation. Redox catalyst with long-term performance is the key issue but is hampered in traditional Fe2O3-based approaches due to Fe sintering. This study reports a one-step sol-gel synthetic method to construct Fe2O3@Hetero-oxide redox catalysts with core-shell structure, leading to outstanding anti-sintering property in TGA analysis (>250 cycles, 5000 min). Fixed-bed reactor tests showed that hydrogen yield approached theoretical value (16.7 mmol/g-Fe2O3), with ∼100 % H2 purity. This result is significantly better than dispersing a mixed ionic-electronic conductor (MIEC) in Fe2O3 matrix using high energy ball milling. Although the latter can enhance the durability due to facilitated O2− and electron transportation, Fe sintering and redox catalysts deactivation is inevitable. This study offers a generalized structure design and synthetic approach for anti-sintering redox catalysts within chemical looping concepts.

Milled graphitic nanoparticle toughened epoxy composites via increased resistance to in-plane crack propagation

Fascinating features of 2D-based carbon materials like graphene have drawn increasing attention to fulfill the desire to enhance the fracture toughness of epoxy composites. However, challenges remain to improve their dispersibility in polymers and increase interaction ability. Thus, work is needed to synthesize alternative cost-effective 2D carbon nanofillers capable of delivering consistent performance as a reinforcer to monitor the fracture toughness of the epoxy composites. The present study demonstrates transforming graphite to ball-milled graphite (BMG) via an effective high-energy wet ball milling process. Herein a noteworthy size reduction is achieved for the BMG ranging from ∼217 to 227 nm. Microscopic investigation spotted an exfoliated 3D networked graphite nanosheet with nanopores. These BMGs were functionalized to attach amine-based silane moieties and were incorporated into the epoxy network. Consequently, even at higher loading levels, they showed their astonishing capability to enhance the crack far field resistance of nanocomposite resulting in significantly improved fracture toughness and energy to ∼2.31 MPa m1/2 and ∼11.30 kJ/m2, respectively. Improvement is ascribed to the better dispersing ability of BMG, which provides a consistent strong interfacial interaction with the epoxy network to modulate material resistance to fracture. Such environmentally friendly nanofillers must be industrially acceptable for synthesizing durable epoxy nanocomposite systems and can be utilized to prepare structural composites.

Nano casein-pectin complex: exploring physicochemical, organoleptic properties, and LAB viability in skimmed milk and low-fat yoghurt.

Protein complexes with a nutritional value, heat stability, and gelling properties with no negative impact on culture viability have promising application prospects in the fermentation industry. The aim of the study was to investigate the possibility of applying physical modification seeking high-protein-fortified yoghurt production using the nano casein-pectin NCP complex as an active colloidal system with enhanced structural and thermal properties and monitor the quality properties of the physicochemical, heat stability, rheological, starter culture viability and sensory evaluation of fortified products comparing with the plain control throughout the cold storage. High-energy ball milling (HEBM) technique was used to produce nanoparticles of casein powder and smaller particles of pectin individually, and particle size and zeta potential was assessed. Deferent Nano casein-pectin (NCP) complex formulations were prepared, their physicochemical properties were assessed including protein quality via Amino Acid Analyzer (AAA), viscosity, thermogravimetric analysis (TGA), and then used in fortification of skimmed milk and low-fat yoghurt to monitor the fortification effects. The particle sizes showed to be ≈166 nm and 602.6 nm for nano-casein and pectin, respectively. Milk fortification with the NCP complex has significantly increased the nutritional value represented in increased protein content (7.19 g/100 g in NCP5); Ca, P, and S content (2,193.11, 481.21, and 313.77 ppm); and amino acid content with first limiting amino acids; histidine (0.89 mg/g), methionine (0.89 mg/g), and low content of hydrophobic amino acids (HAAs) may cause aggregation. NPC fortification enhanced physicochemical properties announced in enhanced viscosity (62. mP.s in NCP5) and heat stability (up to 200°C) compared with control skimmed milk (SM). NCP yoghurt fortification significantly increased protein content to 11 mg/100 g in T5, enhanced viscosity to 48.44 mP.s in T3, decreased syneresis to 16% in T5, and enhanced LAB viability which was translated in preferable sensorial properties. Applying fortification with nanoparticles of the casein-pectin (NCP) complex balanced the amino acid content and improved physicochemical, rheological, nutritional, and sensorial properties and LAB viability, which can be recommended further in functional food applications.

Li8P2S9 solid electrolyte with high ionic conductivity and air stability by Bi2Se3 co-doping

Excellent ionic conductivity and electronic insulation are core properties of solid electrolytes. In this study, we use high-energy ball milling and high-temperature sintering heat treatment to prepare a solid electrolyte, and its ionic conductivity (1.57 × 10−4 S⋅cm−1) is comparable with that of Li8P2S9 in the glass–ceramic state. On this basis, we modify the prepared LPS solid-state electrolyte through Bi2Se3 doping. First-principles computations based on density functional theory (DFT) indicate that Bi2Se3 doping can broaden lithium-ion transport channels and increase the lithium-ion conduction rate. With a doping ratio of 4 %, the ion conductivity reaches 3.02 × 10−3 S⋅cm−1, which offers good insulation to electrons and a stable −0.5 to 5 V (vs. Li/Li+) high-voltage platform. Additionally, Bi2Se3 doping significantly improved the air stability of the LPS solid electrolyte, reducing its adsorption energy to water and preventing the replacement of S by O from H2O.

Influence of partial titanium substitution by its hydride on structure and mechanical properties of TNM-B1 heat-resistant alloy, obtained by SHS powder hot isostatic pressing

This paper investigates the influence of partial substitution of titanium by its hydride on the microstructure and mechanical properties of TNM-B1 alloy obtained by powder metallurgy technology. The impact of the Ti:TiH2 ratio in the reaction mixture and heat treatment modes on the microstructure and mechanical properties of TNM-B1+1%Y2O3 alloy, obtained using high-energy ball milling (HEBM), selfpropagating high-temperature synthesis (SHS), and hot isostatic pressing (HIP) methods, has been examined. It was observed that a 10 % substitution of titanium with its hydride in the reaction mixtures reduces the oxygen content in SHS products from 1 % to 0.8 % due to the generation of a reducing atmosphere during the decomposition of TiH2 in the combustion wave. When the Ti : TiH2 ratio is 90 : 10, highest mechanical properties of TNM-B1+1%Y2O3 alloy were achieved: a compressive strength (σu) of 1200±15 MPa and a yield strength (YS) of 1030±25 MPa. An increase in the proportion of TiH2 results in a higher content of oxygen impurity, leading to the formation of Al2O3, which reduces the strength and ductility of the material. With additional heat treatment of TNM-B1+1%Y2O3 alloy, the globular structure transforms into a partially lamellar one, leading to an increase in σu by 50–300 MPa, depending on the TiH2 content. This attributed to a decrease in the average grain size and a reduction in dislocation mobility during deformation.

The Impact of Al3+ ion substitution on microwave absorption of hexaferrite compound Ba0.6Sr0.4Fe12−xAlxO19 (x = 0.25, 0.50, 0.75, and 1.00)

This paper discusses the impact of Al3+ ion substitution on Fe3+ ions in the hexaferrite compound Ba0.6Sr0.4Fe12−xAlxO19 on the reflection loss value and bandwidth in absorbing microwaves. Hexaferrite Ba0.6Sr0.4Fe12−xAlxO19 (x = 0.25, 0.50, 0.75, and 1.00) was synthesized by high-energy ball milling (HEBM) for forty hours, followed by sintering at 1000 °C in the air for five hours. Then, the crystal structure, formed phase, surface morphology, magnetization, and ability to absorb microwaves in the X-band region were successively characterized. All samples (x = 0.25, 0.50, 0.75, and 1.00) had a single phase with a hexagonal crystal structure. The particle size remained heterogeneous, ranging from 200 to 300 nm, with a platelet-like shape. The maximum amount of magnetic energy that could be absorbed by the material (Ms) increases from x = 0.25 to 0.75 and then decreases slightly for x = 1.00. The maximum value of reflection loss (RLmax) decreases as x increases. For x = 0.25, RLmax is − 16.17 dB (f = 11.06 GHz) with a bandwidth of 3.56 GHz, whereas for x = 1.0, RLmax is −13.94 dB (f = 11.14 GHz) with a bandwidth of 1.68 GHz.

Influence of oxygen distribution on the Li-ion conductivity in oxy-sulfide glasses - taking a closer look.

Lithium thiophosphates are a promising class of solid electrolyte (SE) materials for all-solid-state batteries (ASSBs) due to their high Li-ion conductivity. Yet, the practical application of lithium thiophosphates is hindered by their chemical instability, which remains a prevalent challenge in the field. Oxygen substitution has been discussed in the literature as a promising strategy to enhance stability. Nevertheless, the lack of understanding of the role of synthesis strategy on the resulting structure-property relationship makes it difficult to predict and control the material's behaviour, limiting our ability to fully utilize oxygen substitution as a viable solution. Here, we show that not only the total oxygen content but also the oxygen distribution within the material affects the ion conductivity. By carefully analysing the local structure of oxy-sulfide glasses, we find that few highly oxygenated structural units like [PO4]3- and [PO3S]3- are more detrimental to the ionic conductivity than a larger amount of less substituted units like [POS3]3-. Further, we demonstrate how the oxygen distribution is connected to the synthesis in high-energy ball milling by comparing two different sets of precursor materials. The results may explain the deviations in the past literature. The findings should be transferable to other Li-thiophosphate materials and enable more directed design of new materials.

Effects of TiB2 content on microstructural evolution, microhardness and tribological behaviours of Al matrix composites reinforced with TiB2 particles

In this study, Al2024/TiB2 composites with different TiB2 fractions (5, 10 and 15 vol%) were fabricated by high-energy ball milling and spark plasma sintering. The effects of TiB2 fraction on the microstructure, hardness and wear resistance of the composites were explored to determine the optimal TiB2 content in the composite with optimal properties. An increase in Vickers hardness of the composites correlates with the increased TiB2 content, and the Al2024-15TiB2 composite exhibits the highest hardness. The wear rate of the composite initially increases and then decreases with higher TiB2 content. Notably, the Al2024-10TiB2 composite demonstrates the best wear resistance with a wear rate of 1.14 × 10−4 mm³/Nm, representing a 96.81 % reduction compared to the unreinforced Al2024. The deteriorated wear resistance of the Al2024-15TiB2 composite was attributed to the decreased toughness and severe three-body abrasion caused by the excessive TiB2 particles.

Transformation process of boehmite to γ-Al2O3 induced by high-energy ball milling

Boehmite is transformed into γ-Al2O3 through high-energy ball milling without high-temperature treatment. The AlO4 and AlO5 appear with the amorphization of boehmite and the AlO5 drives the formation of crystalline γ-Al2O3.

Calcite-aragonite transformation in an eggshell: a crucial role of organics and assessment of the impact of milling conditions on its extent using Taguchi design.

Phase transformations during high-energy ball milling, a tool of mechanochemistry, are interesting due to the possible production of metastable phases without the need for artificially introducing high temperatures and pressures. In our work, the transformation of calcite to aragonite in an eggshell is studied in detail. The presence of organic material, in either the naturally present eggshell membrane, or artificially supplied L-cysteine, was found to be crucial for the phase transformation to occur, its decomposition leading to a pressure increase necessary for aragonite formation. The presence of sulfur in the organics seems to be crucial, as corroborated by much lower phase transformation extent when utilizing sulfur-free organics for comparison. The degree of the transformation in an eggshell was strongly dependent on the used milling conditions. The optimization was assessed using the Taguchi method, namely using a 44 orthogonal array. The optimized parameters encompassed milling time, sample mass, milling speed and duration of breaks and it was shown that sample mass has a decisive effect on the amount of obtained aragonite. Under the most efficient conditions, 73.7% of aragonite was obtained. Prolonging milling until 4 hours further boosts the transformation, reaching 89.9% of aragonite, but further milling leads to the collapse of the aragonite structure and pure calcite was observed after 5 hours.

Spontaneous redox reaction-mediated interfacial charge transfer in titanium dioxide/graphene oxide nanoanodes for rapid and durable lithium storage.

Titanium dioxide (TiO2) anodes show significant advantages in ion storage owing to their low cost, abundant sources, and small volume change during cycling. However, their intrinsic low electronic conductivity and sluggish ion diffusion coefficient restrict the application of TiO2 anodes, especially at high current densities. The construction of a covalently-bonded interface in TiO2-based composite anodes is an effective approach to solve these issues. Covalent bonds are usually formed in situ during materials synthesis processes, such as high-energy ball milling, solvothermal reactions, plasma-assisted thermal treatment, and addition of a linking agent for covalent coupling. In this study, we demonstrate that a spontaneous redox reaction between defective TiO2 powder and an oxidative graphene oxide (GO) substate can be used to form interfacial covalent bonds in composites. Different structural characterization techniques confirmed the formation of interfacial covalent bonds. Electrochemical measurements on an optimized sample showed that a specific capacity of 281.3 mA h g-1 after 200 cycles can be achieved at a current density of 1 C (1 C = 168 mA g-1). Even at a high rate of 50 C, the electrode maintained a reversible capacity of 97.0 mA h g-1. The good lithium storage performance of the electrode is a result of the uniquely designed composite electrodes with strong interfacial chemical bonds.

Microstructural and mechanical characterization of AA2124 aluminum alloy matrix composites reinforced with Si3 N4 particulates fabricated by powder metallurgy and high-energy ball milling

Microstructural and mechanical characterization of AA2124 aluminum alloy matrix composites reinforced with Si3 N4 particulates fabricated by powder metallurgy and high-energy ball milling

Combining high energy ball milling and liquid crystal templating method to prepare magnetic ordered mesoporous silica. A physico-chemical investigation.

The physico-chemical investigation of superparamagnetic MCM41 like materials prepared by the novel combination of high energy ball milling and a liquid crystal templating method is presented. Structural, morphological, textural, thermal, and preliminary magnetic characterization demonstrated the successful combination of the two synthesis techniques, avoiding the problems associated with the current methods used for the preparation of magnetic ordered mesoporous silica. MCM41 like materials with high specific surface area values (625-720 m2 g-1) and high mesopore volumes in the range 1-0.7 cm3 g-1 were obtained. The ordered mesoporous structure and accessible pores were maintained after the inclusion of increasing amounts of the magnetic component in the silica structure. All the samples showed superparamagnetic behaviour.

Evidence of oxygen vacancy-mediated ultrahigh SERS sensitivity of Niobium pentoxide nanoparticles through defect engineering: theoretical and experimental studies.

Oxygen vacancy engineering in metal oxide-based semiconductors has emerged as an important area of research for sensing applications, such as Surface-enhanced Raman scattering (SERS), gas sensing, etc. It has the potential to replace high-cost and unstable noble metal-based substrates in the near future. However, improving the SERS enhancement factor in semiconductor-based substrates remains a challenge. In the present study, we demonstrate that oxygen vacancy engineering in Niobium pentoxide (Nb2O5) enables ultrahigh SERS sensitivity. Oxygen vacancies were induced and manipulated in the Nb2O5 nanoparticles via a facile high-energy ball milling method and post-growth oxygen annealing. A high enhancement factor (EF) of 5.15 × 107 was obtained for the Methylene Blue (MeB) molecule on the oxygen-deficient substrate with the lowest detection limit of 10-8 M, which is 2 orders of magnitude lower than the pristine substrate. Through a careful analysis of the experimental data and theoretical calculations, we investigated the underlying mechanism behind the high EF in SERS and showed that the SERS performance is directly proportional to the oxygen vacancy concentration in the Nb2O5 nanoparticles. Density functional theory (DFT) calculation suggests a strong coupling of the vibronic states and an increased charge transfer (CT) efficiency in the Nb2O5-MeB complex mediated through the vacancy-induced trap states in the defective Nb2O5 structure. Finite element method (FEM)-based simulations revealed a field enhancement factor of ∼4.17 × 102 that contributed to the SERS EF, while the remaining is contributed to the oxygen vacancy-mediated charge transfer, i.e., a factor of ∼1.23 × 105 is due to the high CT efficiency, the highest among the reported values. We believe that these findings offer valuable insights into the fabrication of defect-tailored cost-effective semiconductor-based SERS substrates for ensuing applications, such as trace dye detection.

Ball milling synthesis of Fe3O4 nanoparticles-functionalized porous boron nitride with enhanced cationic dye removal performance.

Enhancement of the adsorption performance and recyclability of adsorbents is a crucial aspect of water treatment. Herein, we used one-dimensional porous boron nitride (PBN) as a carrier to load Fe3O4 nanoparticles for the preparation of Fe3O4 nanoparticles-functionalized porous boron nitride (Fe3O4/PBN) via a ball milling method. The high-energy ball milling promoted the creation of a negatively charged PBN surface and facilitated the uniform distribution of Fe3O4 nanoparticles on the surface of PBN. The adsorption performance of Fe3O4/PBN toward cationic dyes could be significantly improved while no enhancement was observed for anionic dyes. The great adsorption performance of Fe3O4/PBN is due to its surface functional groups and surface defects formed in the ball milling process. Moreover, the strong interaction force between Fe3O4/PBN and cationic dyes promotes rapid initial adsorption due to their negatively charged surface. Magnetic measurements demonstrated that Fe3O4/PBN is superparamagnetic. The composites with low loadings of Fe3O4 nanoparticles could be quickly separated from the aqueous solution under a low applied magnetic field, improving their recyclability. This work highlights the role of ball milling in improving the adsorption performance of Fe3O4/PBN and greatly promotes the practical application of Fe3O4/PBN in the field of environmental purification.

G-C3N4 nanosheet supported NiCo2O4 nanoparticles for boosting degradation of tetracycline under visible light and ultrasonic irradiation.

The doping of semiconductor materials through some facile and appropriate methods holds significant promise in enhancing the catalytic performance of catalysts. Herein, NiCo2O4/g-C3N4 composite catalysts were synthesized via a high-energy ball milling method. The microstructure and physicochemical characterization of the as-prepared composites confirmed the successful loading of NiCo2O4 nanoparticles onto the g-C3N4 nanosheets. The NiCo2O4/g-C3N4 composites showed excellent catalytic effect under visible light/ultrasonic irradiation, and the efficiency of tetracycline hydrochloride (TCH) degradation reached 90% within 15 min. The optical properties of g-C3N4 nanosheets were improved by doping, and the diffusion of active materials and carrier migration rate were improved by ultrasonic assistance. Possible catalytic mechanisms and potential pathways of the NiCo2O4/g-C3N4 composites for the degradation of TCH triggered by visible light/ultrasonic irradiation were proposed. This study provides a new strategy for energy-assisted photocatalytic degradation of organic pollutants.

Structural and chemical transformations in the liquid phase during high-energy ball milling of Al and Mg powders with heptane

Structural and chemical transformations in the liquid phase during high-energy ball milling of Al and Mg powders with heptane

Properties of High-Entropy Fe30Co20Ni20Mn20Al10 Alloy Produced by High-Energy Ball Milling.

A high-entropy Fe30Co20Ni20Mn20Al10 (at%) alloy with a face-centered cubic (FCC) crystalline phase was produced through mechanical alloying. This study examined the development of its phases, microstructure, morphology, and magnetic characteristics. Scanning electron microscopy (SEM) was applied to assess the sample morphology in relation to milling times. The changes that the material underwent during milling were investigated using X-ray diffraction. The milling time affected the phase transformation. A single FCC solid solution (crystallite size = 12 nm) was found after 50 h of milling. Additionally, the magnetic characteristics were examined and shown to be associated with microstructural changes. The powder mixture exhibited behavior consistent with soft magnetics, with an Hc value of 8 Am-1 and an Ms value of 165 emu/g. The excellent soft magnetic characteristic may be related to the stability of the FCC phase, which was generated following a 30 h milling process. In addition, the low value of Ms may have originated from the presence of Al atoms in the solid solution and the development of large densities of interfaces and crystal defects.