Ball Milling Parameters Research Articles

Influence of Planetary Ball Mill Parameters on Powder Flowability of AlSi10Mg with Niobium Carbide Using Central Composite Design (CCD)

The hypoeutectic aluminum alloy (AlSi10Mg) is a well-known candidate material used predominantly for its processability and inherent characteristics in metal-based additive manufacturing. Besides, transition metal carbide, such as niobium carbide (NbC), is added to the AlSi10Mg, enhancing its mechanical properties and preferably its wear resistance to the matrix. However, in additive manufacturing, the mixed powder’s flowability is a prerequisite for determining the final properties of the specimens. In this study, mixed powder flowability analysis was carried out through the regular mixing of AlSi10Mg with a varying weight percentage of NbC conducted in the planetary ball mill with different time, speed, and NbC composition following the Central Composite Design (CCD), with a total of 20 experiments. Here, regular mixing was preferred to retain the morphology of the AlSi10Mg (spherical shape) instead of ball milling, which contributes to the degradation of the powder’s shape and size. Finally, based on the combined analysis of apparent density (AD), tapped density (TD), and static angle of repose (SAoR), the flowability characteristics of the mixed powders (AlSi10Mg + X % NbC) were evaluated. The optimum combination (AlSi10Mg + X% NbC) was attained based on the composite desirability criteria.

Leakage Rate Control of Magnetic Powder Seals by Lubricant Coatings on Magnetic Nanoparticles and Flow Field Simulation

Magnetic fluid seals (MFSs) have been a popular sealing method, with unique advantages compared to traditional mechanical seals, such as zero leakage, long lifetime, and low resistance torque. However, restricted by the properties of carrier fluids, MFSs cannot work under extremely high or low temperatures. To ensure stability, the pressure capability per stage is also limited. Recently, a novel sealing method using nano-micro magnetic powders has been presented to solve the problems, and leakage rates turn out to be a main focus. Here, we realize the leakage rate control by lubricant coatings on magnetic nanoparticles. Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanoparticles coated with solid lubricants are prepared by the high-energy ball milling method. Effects of different types of lubricants and ball milling parameters on the leakage rate are studied by magnetic powder sealing experiments. Permeability of magnetic powders is estimated from the experimental data. Furthermore, the flow field distribution of a real magnetic powder seal (MPS) is simulated.

Effect of solid loading on properties of Y2O3–Al2O3–Nd2O3 powder mixtures obtained by planetary ball milling and ceramics based on them

The effect of the solid loading (41–50 wt%) of the slurry on granulometric composition and physico-chemical characteristics of Y2O3–Al2O3–Nd2O3 powder mixtures obtained by planetary ball milling has been studied for the first time. It was shown that the particle size distribution of powder, its Zeta potential, and specific surface area depend on the solid loading of the milled slurry and, consequently, on the interparticle distance during milling. The interparticle distance decreases from 200 nm to 142 nm with an increase of solid loading in the range of 41–50 wt%. It was shown that for the solid loading of 47 wt%, the convergence of particles to a distance comparable to their median diameter promotes subsequent clustering of particles. This facilitates the sintering of highly-homogenous ceramics. It was found that solid loadings in the 46–50 wt% range is useful for obtaining high-quality Nd:YAG transparent ceramics. The lowest optical losses optical losses of 1 × 10−3 cm−1 and the highest in-line transmittance of 84.1%@1064 nm were obtained for 1 at.% Nd:YAG transparent ceramics (22 × 3 × 4 mm3) prepared from slurries with 47 wt% solid loading (taking all other ball milling parameters fixed). If the interparticle distance in the powder is higher (solid loading of 41 wt%) than the median particle diameter, the ceramics are characterized by significant residual porosity due to the survival of large particles (insufficient milling).

Microstructure evolution and properties of a Cu-5 wt% Mo alloy with high conductivity and high anti-soften temperature

A Cu-5 wt% Mo alloy with high conductivity and high anti-soften temperature were fabricated by combining mechanical alloying with spark plasma sintering (SPS). Cu-5 wt% Mo mixed powders with four kinds of ball milling parameters were prepared by mechanical alloying. The sintered Cu-5 wt% Mo alloy was rolled and aged. The rolled Cu-5 wt% Mo alloy achieved a relative density of 98.19%, an electrical conductivity of 92.6%IACS, a microhardness of 128.6 HV, an ultimate tensile true stress of 441.2 MPa, and an elongation of 24.9%. Nanoscale Mo precipitates were formed during aging process. The aged Cu-5 wt% Mo alloy reached an electrical conductivity of 96.5%IACS and an anti-soften temperature of 950 ℃. These findings are instructive for the development of copper alloy materials with high conductivity and high anti-soften temperature.

Fabrication of Cu-adhered silicon carbide particles and its effect on properties of Fe-based matrix composites

In present study, copper powders (Cu) and silicon carbide (SiC) particles were used to produce Cu-adhered SiC particles (Cu/SiC), which were used to reinforce Fe-based matrix materials to modify properties. The orthogonal experimental design was used to investigate the relationship between ball mill parameters and particle size. Next, the mixed powders were pressed at 500 MPa using a hydraulic press. Then, the green compacts were wrapped in graphite powders, and sintered using a resistance furnace. Metallurgical microscopy, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffraction were employed to investigate the microstructures, element distribution, and phase of SiC-reinforced Fe-based matrix composites. The properties of the SiC-reinforced metal matrix composites were determined using the Microhardness test and Charpy pendulum impact test. The orthogonal experimental results indicated that the influence degree of milling parameters on particle size was the powder to ball ratio>milling time>milling speed. The milling parameters to obtain the smallest Cu/SiC particle were powder to ball ratio of 20:1, milling time of 15 h, and milling speed of 300 r min−1. However, the adhesive effect was bad. The properties test results indicated that Cu/SiC particles reinforced with Fe matrix composites had better properties. Furthermore, the hardness and impact toughness improved up to 239.97 HV0.5 and 12.1 KJ·m−2, respectively. Moreover, compared to raw SiC particles, the hardness and impact toughness increased by 12% and 15%, respectively. The improvement in properties was attributed to the Cu adhesion to the SiC surface, which effectively alleviated the difference in thermal expansion coefficient between SiC and Fe, and formed a chemical bond at the interface to improve the interfacial binding

Enhancement in hydrogenation properties of ball-milled AB5-type hydrogen storage alloy through catalyst

Ball-milling of the hydrogen storage alloy has been shown to improve many hydrogenation properties under specific ball-milling parameters. The present investigation is based on further improvement in the hydrogenation properties through the addition of a catalyst. Catalysts are known to increase the rate of reaction. In the present investigation, rigorous studies have been performed on the various factors affecting the hydrogenation reaction through the addition of catalyst during ball-milling. The basic idea of the mechanism of catalyst is the availability of the free valencies behaving like active centres for promoting the reaction rate. Free valencies are more crowded at corners, peaks and cracks on the catalyst. The rough surface of the catalyst and finely dispersed catalyst are more effective in promoting the reaction rate. In the present investigation, various factors like spillover effect; defects introduced to the catalyst and hydrogen storage alloy during ball-milling; elasticity of metal hydride matrix; nature, size, hardness, number of unpaired electrons and variable valency of catalyst; the electronegative difference between catalyst and metal hydride; electron distribution and orbital structure; the ability of the catalyst to transfer stable diatomic hydrogen into the desired ionic configuration; binding between H atoms and catalyst and lowering of activation energy due to catalyst have been discussed in terms of their effect on hydrogenation properties. It has been found that all these factors help in lowering the activation energy for the hydrogenation process and improve the hydrogenation properties.

Laser powder bed fusion of diamond/N6 MMCs enabled by Ni-Ti coated diamond particles

Metal matrix composites (MMCs) have received increasing attention and there is a growing interest in additive manufacturing (AM) of MMCs with complex shapes recently. However, it remains challenging to control the quality of composite powder for MMCs. In this study, the diamond particles are firstly coated with thin layers of Titanium and Nickel to ensure strong interface bonding with the Nickel matrix. The influence of ball milling parameters on the Ni-Ti coated diamond/N6 composite powder particles preparation and the effect of processing parameters during laser powder bed fusion (LPBF) on the densification of and defects in the fabricated samples are analyzed. In the ball milling stage, the results show that highly flowable composite powder particles for LPBF can be obtained under a ball milling time of 4 h, a speed of 250 rpm, and a ball-to-powder ratio of 2:1. With the optimized composite powder, a set of Ni-Ti coated diamond/N6 MMCs are further manufactured under the laser powers of 150, 160, and 170 W and scanning speed of 250 mm/s, the MMC samples have relative densities higher than 99%. Our study demonstrates the feasibility of manufacturing dense diamond/N6 and other similar MMCs with appropriate coating, ball-milling and LPBF parameters.

Effect of Milling Parameters on Mechanical Properties and In Vitro Biocompatibility of Mg-Zn-Co Ternary Alloy

Magnesium (Mg) is a potential candidate for biomedical implants, but its susceptibility to suffer corrosion attack in human body fluid limits its practical use. Thus, alloying Mg with other metal elements is the most effective strategy to improve its mechanical properties and biocompatibility. Herein, we report a Mg-Zn-Co ternary alloy (85-10-5 wt %) synthesized by the mechanical alloying technique. Ball-milling parameters such as ball size and milling time were varied to obtain better alloy properties. After compaction and sintering, the obtained alloy samples were subjected to various characterizations, including grain, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD), microhardness and nanoindentation analyses. In vitro biocompatibility analysis of different alloys was also performed with MC3T3-E1 osteoblasts. Grain analysis confirmed the even dispersion of particles, while SEM analysis showed the formation of laminates, spherical and fine particles with an increase in time and varied ball size. XRD results further confirmed the formation of intermetallic compounds. The microhardness of samples was increased with the increase in milling time. The Young’s modulus of ternary alloys obtained from nanoindentation analysis was comparable to the modulus of human bone. Moreover, in vitro analysis with osteoblasts showed that the developed alloys were noncytotoxic and biocompatible.

Effect of ball-milling parameters on the rheological properties of mold powder slurry

In this study, mold powder slurries with high solid loading and low viscosity were prepared during the ball-milling process for improving the homogeneity and mechanical properties of granules after spray-drying. The effect of ball-milling parameters, such as solid loading, binder/dispersant content, and ball-milling time, on the flowability, dispersibility, stability, and rheological behavior of mold powder slurries was systematically investigated by rheology observation and sedimentation tests. As these parameters varied, the slurry exhibited the shear-thinning behavior of a non-Newtonian fluid with a shear rate range of 0–50 s−1, which was adequately described by the Herschel-Bulkley model. The optimal parameters that optimized the flowability, dispersibility, and stability of the slurry, along with its rheological behavior, were chosen as follows: solid loading, 60 wt%; modified sodium carboxymethyl cellulose binder content, 1.0 wt%; sodium tripolyphosphate dispersant content, 0.5 wt%; ball-milling time, 60 min.

Mercury removal by the S2Cl2 modified biomass coke with mechanochemical versus impregnation method

Mercury is a global pollutant. In this work, wood sawdust-based biomass coke and S2Cl2 were selected as the raw material and modifier, respectively. Two modification methods were adopted to prepare the mechanochemical S2Cl2-modified biomass coke (BC-S2Cl2-MC) and S2Cl2 impregnated-modified biomass coke (BC-S2Cl2-IM). The flue gas fixed mercury-removal experiment rig was used to evaluated the mercury removal performance of the adsorbents. The Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS) were adopted to characterize the surface physical and chemical properties of some typical samples. Hg temperature-programmed desorption (Hg-TPD) was used to analyze the main mercury forms in the used adsorbents. The results show both mechanochemistry and impregnation methods can significantly improve Hg0 removal performance with the addition of S2Cl2. Increasing S2Cl2 addition amount increases the Hg0 removal efficiency of BC-S2Cl2-MC overall. Considering the economy and mercury removal performance, 800 μL is the optimum addition amount for the 3 g raw biomass coke with the Hg0 removal rate of 91.94%. The change of ball milling parameters within a certain range has little effect on the mercury removal performance of BC-S2Cl2-MC. The best ball milling parameters in this work are a ball-to-material ratio of 10:1 and big balls (diameter = 20 mm), which corresponds to the Hg0 removal rate of 97.12%. Chemical adsorption plays a great part in the Hg0 removal of BC-S2Cl2-MC and BC-8S2Cl2-IM. The surface functional groups such as O–H, C = O, C = S and thiophen/element sulfur and sulfoxide are the main Hg0 adsorption active sites. HgS (black) is the main mercury form in the used BC-S2Cl2-MC and used BC-S2Cl2-IM. The mechanochemical method has more prospects for industrial application than the impregnation method.

Use of Taguchi method for high energy ball milling of CaCO3

Taguchi’s method was applied to investigate the effect of main high energy ball milling (HEBM) parameters: milling time (MT), ball to powder weight ratio (BPWR), and milling speed (MS) on the CaCO3 crystallite size. The settings of HEBM parameters were determined by using the L9 (33) orthogonal experiments array (OA). The as-received and milled powders were characterized by X-ray diffraction (XRD) scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy. The crystallite size of CaCO3 varied between 140 and 540 nm depending on the HEBM conditions. The analysis of variance (ANOVA) was used to find the significance and percentage of contribution of each milling parameter. It was established that the MT is the most effective parameter followed by MS and BPWR. A confirmation test was carried out with a 90% confidence level to illustrate the effectiveness of the Taguchi optimization method. The optimum milling parameter combination was determined by using the analysis of signal-to-noise (S/N) ratio. Based on the S/N ratio analysis, optimal HEBM conditions were found MT 10 h, MS 600 revolutions per minute (rpm), BPWR 50:1.

Investigation of the third-order optical nonlinearity of Au/GO-CeO2 nanocomposites under different high-energy ball milling parameters

A high-energy ball milling process along with the hydrothermal method was applied to synthesize Au/GO-CeO2 nanocomposites. X-ray diffraction analysis and FT-IR spectroscopy confirmed the successful synthesis of nanocomposites. The ball milling parameters dependence of the nonlinear optical response of Au/GO-CeO2 nanocomposites was investigated by using the Z-scan measurements under pulsed Nd: YAG laser irradiation at 532 nm. The measurements showed that Au/GO-CeO2 nanocomposites have negative nonlinearity which can be controlled by ball milling parameters to achieve higher values for third-order nonlinear optical susceptibility of the order of 10−8 esu. The investigations showed that ball milling parameters such as ball milled time and the number of hardened zirconia oxide balls are important factors in the resultant nonlinear optical parameters. The results suggest that Au/GO-CeO2 nanocomposites with a strong nonlinear optical response can be a promising nonlinear medium that can open a new avenue to graphene-based nonlinear optics.

Evaluation of MWCNT Particles-Reinforced Magnesium Composite for Mechanical and Catalytic Applications.

Aluminum, magnesium, and copper materials must have increased mechanical strength with enhanced wear and corrosion resistance. Substantial research focused on reinforcing hard particles into low-strength materials using stir casting or powder metallurgy. This work is intended to develop the magnesium hybrid matrix with the dispersion of boron carbide (B4C) and multiwall carbon nanotubes (MWCNTs). Hybrid magnesium composites are prepared, although the powder metallurgy route considers different process parameters. Statistical analysis such as Taguchi L16 orthogonal array is involved in this work. It is used to find the magnesium hybrid samples' minimum and maximum wear, corrosion, and microhardness levels. Powder metallurgy parameters are B4C (3%, 6%, 9%, and 12%), MWCNT (0.2%, 0.4%, 0.6%, and 0.8%), ball milling (1, 2, 3, and 4 h), and sintering (3, 4, 5, and 6 h). The ball milling parameters are extremely influenced in the wear test analysis. Minimum wear losses are obtained as 0.008 g by influencing the 4 h ball milling process. Similarly, 3 h of sintering time offered a minimum corrosion rate of 0.00078 mm/yr. In microhardness analysis, the percentage of MWCNTs is highly implicated in narrow hardness resulting in the hardness value of 181. The hardness value is recorded using 0.2% MWCNTs in the magnesium alloy AZ80.

Highly enhancing electromagnetic properties in Fe-Si/MnO-SiO2 soft magnetic composites by improving coating uniformity

Fe-Si/MnO-SiO2 soft magnetic composites (SMCs) are prepared by sintering ball milled Fe-Si/MnO2 core–shell structured composites. The correlation between the coating uniformity and electromagnetic properties have been investigated via adjusting ball milling parameters in detail. The results indicate that uniform MnO2 coating can be transformed into MnO-SiO2 composite coatings with high insulation due to the high temperature reaction between MnO2 and Si. Agate ball is more effective than stainless steel ball to improve the uniformity of MnO2 coating as well as the electromagnetic properties such as significantly higher resistivity, lower core loss and better frequency stability of permeability. Moreover, increasing the ball milling time from 4 h to 24 h can obviously improve the coating uniformity and thus result in the remarkable increase of the resistivity from 2.4 mΩ·cm to 356.9 mΩ·cm. And the core loss and dynamic loss decrease rapidly while the Ms shows a slight decline. When the ball milling time reaches 24 h, the Fe-Si SMCs exhibits superior magnetic properties such as high Ms (181.0 emu/g), very low core loss (361.5 kW/m3 at 100 kHz) and good frequency stability of permeability (65) from 50 Hz to 1000 kHz.

Effect of Ball Mill Parameters’ Variation on the Particles of a Mechanical Activation-Assisted Leaching: A Hydrometallurgical Mechanics

Effect of Ball Mill Parameters’ Variation on the Particles of a Mechanical Activation-Assisted Leaching: A Hydrometallurgical Mechanics

The influence of ball milling processing variables on the microstructure and compaction behavior of Fe–Mn–Cu alloys

Abstract In the present study, twenty seven [(Fe–35wt%Mn)100−x –Cu x ] alloy samples were processed using high-energy ball milling, followed by uniaxial compaction under different processing conditions. The compressibility behavior in terms of relative density (RD) was examined with milling time (MT: 1 h, 5.5 h, and 10 h), ball-to-powder mass ratio (BPMR: 5:1, 10:1, and 15:1), milling speed (MS: 100 rev/min, 200 rev/min, and 300 rev/min), compaction pressure (CP: 25–1,100 MPa), and alloy composition (Cu content [CC]: 0 wt%, 5 wt%, 10 wt%). Particle size analysis using X-ray diffraction (XRD) and high-resolution scanning electron microscopy (HRSEM) combined with energy-dispersive X-ray spectroscopy (EDS) were applied for microstructural characterization. The experiments were conducted based on the central composite design of response surface methodology (RSM), and the results for the compaction behavior were examined with the input parameters. Analysis of variance (ANOVA) test was applied to determine the most significant input parameters. The attained results revealed that increasing ball milling parameters (MT, MS, and BPMR) resulted in significant enhancements in the microstructural features, such as improved elemental dispersion and occurrence of refined particles with substantial decrease in the crystallite size. On the other hand, increasing the input parameters exhibited a detrimental influence on the compactibility and RD of the alloys. In addition, increasing the CC resulted in a substantial improvement in the compressibility and RD of the developed alloys. The recommended combination of the studied variables includes MT for 5 h, MS for 150 rev/min, BPMR of 10:1, and 10 wt%Cu to attain an acceptable compromise of enhanced microstructure features, improved compaction response, and RD.

Microstructural Design of Ba0.5La0.5Co0.5Fe0.5O3 Perovskite Ceramics.

Ba0.5La0.5Co0.5Fe0.5O3−δ was synthesized in the solid-state reaction route. The influence of ball milling parameters (such as milling media size, angular velocity, and time), pelletizing pressure, and annealing parameters on the microstructure was studied. The grain size distribution and density or specific surface area changes were investigated in each approach while the individual parameters were changed. The evaluation of BLCF synthesis parameters enables tailoring the microstructure to various applications. It was observed that with lowering the size of milling balls and increasing the angular velocity the material will be porous and thus more appropriate as electrode material in proton ceramic fuel cell or electrolyzer. An increase of time, balls diameter, and/or angular velocity of milling enables one to densify the material in case of membrane application in, e.g., as a gas sensor. The significant influence on densification has also annealing temperature increase. Applying 1200 °C during annealing leads to dense material, while at 1100 °C shows visible porosity of the product. In this work, we present the results of the BLCF synthesis parameters change allowing the selection of appropriate parameter values depending on the further application as PCCs.

Analysis of individual and interaction effects of processing parameters on wet grinding performance in ball milling of alumina ceramics using statistical methods

It is of great interest and necessary to closely investigate and understand how ball milling parameters can affect the overall quality of milled ceramic powders. In this paper, we analyzed the individual and interaction effects of the key processing parameters on the wet grinding performance in a ball mill for alumina powder using statistical methods. The grinding performance was evaluated based on three quality characteristics of milled alumina powder: the median particle size (d50), width and skewness reflecting the shape of particle size distributions (PSDs). For this determination, the volume percentage of slurry, solid content, milling speed, milling time, and ball size are regarded as the key parameters affecting these characteristics. Milling experiments were designed by central composite design, and an experimental dataset was collected systematically. The analysis results show that it is worthwhile to consider not only the d50 but also the shape of the PSDs when assessing the ball milling performance. These results are useful for the production of high-quality alumina powders in ceramic industries.

Nanostructured high-entropy alloys by mechanical alloying: A review of principles and magnetic properties

The principles and magnetic properties of nanostructured high-entropy alloys (HEAs) processed by mechanical alloying are overviewed. Firstly, the general concepts of HEAs (multi-principal element alloys with ≥5 elements) and phase formation rules are briefly reviewed. Subsequently, the processing of nanocrystalline and amorphous HEAs by mechanical alloying and the effect of high-energy ball milling parameters are summarized. Finally, the magnetic properties of nanostructured HEAs are critically discussed to infer some general rules. In summary, a higher content of ferromagnetic elements (e.g. Fe, Co, and Ni) normally results in a higher saturation magnetization. The as-milled products with solid solution phases show better soft-magnetic properties compared to the fully amorphous phases, and increasing the amount of the amorphous phase decreases the saturation magnetization. The magnetic properties are also influenced by processing (such as sintering) and thermal history through the alteration of phases and crystallite size.

Effect of ball milling process on the mechanical and thermal properties of the nanodiamond/2024Al composites

In this study, 5 wt.% nanodiamond (ND) reinforced 2024Al matrix composites (ND/2024Al) were fabricated with various ball milling processes. The microstructure, compressive yield strength (σyc) and coefficient of thermal expansion (CTE) of ND/2024Al composites were investigated. It is found that the addition of 5 wt.% NDs significantly increases the σyc and decreases the CTE of 2024Al. High energy ball milling further increases σyc and decreases CTEs of ND/2024Al composite due to it enhances the fine grain strengthening of α-Al matrix and the dispersion strengthening of NDs, decreases the thermal mismatch stress at the ND/α-Al matrix interface, and increases the constraint of NDs on α-Al. The composites fabricated by the combinations of ball milling speeds and times of (5−7) h×(200−250)rpm and 9 h×300 rpm have the highest σyc and the lowest CTE respectively. Considering the different influence of ball milling parameters on σyc and CTEs, a evaluation coefficient α=σycC⋅εkcCσycM⋅εkcM⋅CTEMCTEC is proposed to evaluate the synergistic influence of mechanical properties and CTEs on the dimensional stability of ND/2024Al composites. Large value of α may lead to high dimensional stability of material, hence the α can be used to determine the ball milling parameters.The ball milling process of 250−300 rpm ball milling speeds and 5−7 h ball milling times are recommended based on α, which causes a 95–100 % increase in σyc and a 30–35 % decrease in CTE compared with 2024Al alloy, respectively.