Milling Treatment Research Articles

Ball Milling Treatment of Nb and B Nanoparticles Modified TiAl4822 Composite Powder and Its Effect on Powder Bed Quality and Powder Spreadability in Additive Manufacturing

Ball milling treatment is a low‐cost and achievable large‐scale production method for preparing the composite powder used for the laser powder bed fusion (LPBF) process. For the ball‐milled composite powder, good powder spreadability and composition homogeneity are essential for obtaining the LPBF‐fabricated part with good forming quality. In this article, the Nb and B nanoparticles modified TiAl4822 composite powder with a nominal composition of Ti‐47.53Al‐1.98Cr‐2.81Nb‐0.15B are prepared via ball milling. It is found that the physical properties of the composite powder are more sensitive to the milling time than the milling speed and ball‐to‐powder ratio. Long‐time milling is inclined to cause the formation of broken particles, poor powder flowability, and high oxygen contamination. Besides, the process maps between the ball milling energy E t and particle size distribution width, the static angle of repose, composition inhomogeneity, and oxygen content are established, respectively. Results show that when the applied E t is insufficient or excessive, the degree of sphericity or composition homogeneity always worsens. In these cases, deposition defects such as line or area defects are more prone to occur, due to the enhanced particle rearrangement resistance induced by the addition of nanoparticles.

Reducing freshwater consumption in pulp and paper industries using pinch analysis and mathematical optimization

The pulp and paper (P&P) industries are classified among the water-intensitive industries. In this work, implementation of the Water Closed-Loop System (WCLS) in a P&P factory to reduce water consumption and wastewater generation was reported. First, the water and steam network of the mill was synthesized, and water sinks and sources along with their flowrates were identified. The key pollutants, including chemical oxygen demand (COD), total suspended solids (TSS), and total dissolved solids (TDS), were pinpointed and acceptable levels for water sinks were acquired. In the second step, by using water pinch analysis with the direct-reuse approach, each limiting pollutant was investigated, and the maximum reduction in freshwater consumption equal to 36.9 % was obtained by considering TSS as the only pollutant. The minimum potential for reducing water consumption belonged to COD (4.0 %) and TDS (18.9 %). In the regeneration-reuse approach, the incomplete performance of the mill's treatment plant in removing COD and TDS resulted in no improvement in the results of the previous step. In the case of TSS alone, the reduction in freshwater consumption increased to 93.3 %. Mathematical optimization was used to study all limiting contaminants simultaneously. The direct-reuse approach achieved a 4.0 % reduction in water consumption, while the regeneration-reuse did not change water consumption compared to the direct-reuse approach, emphasizing the incomplete operation of the treatment plant. Finally, the output contaminants levels of a hypothetical decentralized and modified existing treatment plant were estimated using literature. In this case, the freshwater consumption of the mill declined by 93 %.

Effect of Shearing and Heat Milling Treatment Temperature on the Crystallinity, Thermal Properties, and Molecular Structure of Rice Starch.

Rice flour is produced by various methods for use in the food industry, but little is known about how the structure of starch is affected during rice flour production. In this study, the crystallinity, thermal properties, and structure of starch in rice flour were investigated after treatment with a shearing and heat milling machine (SHMM) at different temperatures (10-150 °C). Both the crystallinity and gelatinization enthalpy of starch showed an inverse relationship with the treatment temperature; rice flour treated with the SHMM at higher temperatures showed lower crystallinity and gelatinization enthalpy than that treated at lower temperatures. Next, the structure of undegraded starch in the SHMM-treated rice flour was analyzed by gel permeation chromatography. A significant reduction in the molecular weight of amylopectin was observed at high treatment temperatures. Chain length distribution analysis showed that the proportion of long chains (degree of polymerization (DP) > 30) in rice flour decreased at temperatures ≥ 30 °C. By contrast, the molecular weight of amylose did not decrease. In summary, the SHMM treatment of rice flour at high temperatures resulted in starch gelatinization, and the amylopectin molecular weight decreased independently, due to the cleavage of amorphous regions connecting the amylopectin clusters.

Effects of shear emulsifying/ball milling/autoclave modification on structure, physicochemical properties, phenolic compounds, and antioxidant capacity of lotus (Nelumbo) leaves dietary fiber.

Lotus (Nelumbo) leaves are rich in polyphenols and dietary fiber, which have the potential as a high-quality fiber material in functional food. However, lotus leaves exhibit dense structure and poor taste, it is vital to develop appropriate modification methods to improve the properties of lotus leaves dietary fiber. In this study, the effects of three modification methods with shear emulsifying (SE), ball milling (BM), and autoclave treatment (AT) on structure, physicochemical properties, phenolic compounds, and antioxidant capacity of lotus leave dietary fiber (LDF) were evaluated. SEM indicated that there were significant differences in the microstructure of modified LDFs. FT-IR spectra and X-ray diffraction pattern of modified LDFs revealed similar shapes, while the peak intensity and crystalline region changed by modification. SE showed the greatest effect on crystallization index. SE-LDF had the highest water holding capacity, water swelling capacity, and bound phenolic content in LDFs, which increased by 15.69, 12.02, and 31.81%, respectively, compared with the unmodified LDF. BM exhibited the most dramatic effect on particle size. BM-LDF had the highest free phenolic and total phenolic contents in LDFs, which increased by 32.20 and 29.05% respectively, compared with the unmodified LDF. Phenolic compounds in LDFs were mainly free phenolic, and modifications altered the concents of flavonoids. The BM-LDF and SE-LDF exhibited higher antioxidant capacity than that of AT-LDF. Overall, SE-LDF showed better physical properties, and BM-LDF showed better bioactive components. SE and BM were considered to be appropriate modification methods to enhance the properties of LDF with their own advantages.

Highly thermally conductive polymer-based composites with 3D exfoliated BNNS/functionalized SiC networks prepared by rapid solidification and hot pressing

High thermal conductivity polymer-based packaging materials can achieve effective heat diffusion, which is of great significance for the performance and longevity of electronic devices. Exfoliated boron nitride nanosheets (s-BNNS) containing smaller particle sizes, fewer layers, and more hydroxyl groups were prepared by ball milling and strong ultrasonic treatment in this work. The functionalized SiC (m-SiC) was obtained by ternary blend organic silanol modification, which promoted the compatibility between fillers and fillers, as well as fillers and matrix. By a facile strategy of rapid solidification and hot pressing, s-BNNS were distributed between and on the surface of m-SiC fillers to form m-SiC/s-BNNS/polyamide 6/polyethylene terephthalate (PA6/PET) composite films with 3D thermally conductive networks. The thermal conductivity of m-SiC/s-BNNS/PA6/PET composite reached a superior 6.98 W/(m·K) at a filler loading 85 wt%, which was 124.67% higher than that of SiC/PA6/PET composite without 3D thermal network formation. More interestingly, reverse non-equilibrium molecular dynamics (RNEMD) simulations show that the hybrid SiC/BNNS filler greatly reduces the porosity within the composite compared to only one kind of filler, which in turn improves the composite's thermal conductivity.

乾式機械的処理を利用した無溶媒均一沈殿法によるヘマタイトナノ粒子の合成

Hematite (α-Fe2O3) nanoparticles were synthesized by a solvent-free homogeneous precipitation method using urea hydrolysis via dry mechanical treatment of urea and ferric nitrate nonahydrate for activation. This novel method consists of high-energy ball milling of the raw materials and subsequent heating of the activated liquid precursor, which can provide smaller-sized nanoparticles than conventional methods. The milling and heating conditions were systematically investigated in detail. It was found that the hematite formation can be promoted by milling ferric nitrate nonahydrate and urea simultaneously under dry conditions even when relatively gentle milling and heating treatments were employed. The hematite nanoparticles had a similar crystallite size and particle diameter regardless of the conditions. This method can contribute to large-scale environmentally-friendly synthesis of fine hematite nanoparticles.

Ordered-Range Tuning of Flash Graphene for Fast-Charging Lithium-Ion Batteries

Graphene has yet to be mass produced, so practical fast-charging lithium-ion battery (LIB) prototypes based on graphene are scarce. Graphene suffers from long in-plane and reluctant in-depth lithium diffusion due to its defect-free atomic arrangement, resulting in unsatisfactory rate performance as LIB anodes. In this work, combinatorial flash joule heating and ball milling treatment are implemented to enable gram-scale production of graphene in seconds (known as flash graphene, FG) and in-plane ordered-range modulation of graphene architectures. Following the ball milling, the defect-deficient turbostratic FG is transformed to defect-rich cracked FG (CFG), which has shortened ordered ranges and larger interlayer spacings. The CFG anode outperforms FG, commercial carbon black, and graphite electrodes in terms of specific capacity and rate performance due to open channels and shortened pathways for Li+ transport. Moreover, it shows outstanding cycling stability with a high capacity retention of 99% at the 500th cycle. Furthermore, it works well with the LiFePO4 cathode, enabling fast-charging LIB full battery with a state of charge of 77 and 62% at 2C and 4C, respectively. This research on graphene production and structural engineering provides a practical application for the commercial potential of fast-charging LIBs.

Effect of ball milling and solid solution treatment on the microstructure and interfacial behaviors of ZrMgMo3O12p/2024Al composites

ZrMgMo3O12 is a negative expansion material, while 2024Al alloy is a positive expansion material. The difference in thermal expansion coefficients between them will cause thermal mismatch stress at the interface in ZrMgMo3O12p/2024Al composites. Therefore, the interface behaviors of ZrMgMo3O12–Al determine the properties of ZrMgMo3O12p/2024Al composites to a great extent. The effects of ball milling and solid solution treatment on the microstructure and interface behaviors of 10 vol% ZrMgMo3O12p/2024Al composites were studied to improve the reticular microstructure of ZrMgMo3O12 distributed at the grain boundary of the α-Al matrix. The results showed that with increasing milling energy, the microstructure of the composites changed from reticular to equiaxed, and the distribution of ZrMgMo3O12 reinforcements in the matrix was more uniform. The content and size of the primary phase Al2Cu decreased with increasing solid solution treatment time. In addition, only ZrMgMo3O12–Al, Al2Cu–Al12Mo and Al–Al12Mo interfaces can be observed, but it is difficult to observe the interfaces of ZrMgMo3O12–Al12Mo in the composites milled for 12 h and solution treated for 24 h, which is related to the decomposition mechanism of ZrMgMo3O12. The decomposition mechanism is as follows: Al atoms from the α-Al matrix captured O atoms from ZrMgMo3O12 to form Al2O3. ZrMgMo3O12 simultaneously released Mo, Zr and Mg atoms. Mo atoms were enriched and nucleated in situ and precipitated with Al atoms to form the intermetallic compound Al12Mo, while Zr and Mg atoms entered the α-Al matrix to form a solid solution.

Tensile strength and anisotropy of repeated hot-rolled carbon nanotube/aluminum matrix composites

This study aims to strengthen carbon nanotube (CNT)/Al composites, which were fabricated by a combination of spark plasma sintering (SPS) and repeated hot rolling techniques. Dry ball milling was conducted to uniformly disperse CNT in Al powders. The microstructures of the CNT/Al composites including dispersibility of CNT were observed using a scanning electron microscope (SEM) and transmission electron microscope (TEM). Ball milling treatments promoted to reduce the number of CNT aggregations and increase C concentrations in the CNT aggregations in the composites. Anisotropic tensile behavior was also investigated, which demonstrated that the post-SPS repeated hot rolling can highly enhance the tensile strength as well as deformability of the composites.

Impact of different corn milling methods for high-moisture and dry corn on finishing cattle performance, carcass characteristics, and nutrient digestion.

Two experiments were conducted to evaluate the effect of different corn milling methods for high-moisture and dry corn on finishing cattle performance, carcass traits, and nutrient digestion. In experiment 1, steers (N = 600 [60 pens]; initial body weight [BW] = 402 ± 17 kg) were fed for 134 d to evaluate the effect of milling method and corn type on performance and carcass characteristics. Treatments were evaluated as a 2 × 3 factorial design with factors being milling method (Automatic Ag roller mill [ROLL] or hammer mill [HAMMER]) and corn type (high-moisture [HMC], dry [DC], or 50:50 blend of HMC and DC [BLEND]). There were no milling method × corn type interactions for final BW, gain (ADG), or dry matter intake (DMI; P ≥ 0.32), but there tended to be an interaction for G:F (P = 0.09). Cattle fed ROLL HMC had 4.7% greater gain:feed (G:F; P ≤ 0.01) with 55% lower fecal starch (P < 0.01) compared to HAMMER HMC, whereas processing did not impact (P = 0.74) G:F in DC diets. There were no further effects (P ≥ 0.14) on performance or carcass traits regardless of milling method or corn type. In experiment 2, seven ruminally fistulated steers were utilized in a 4 × 7 incomplete Latin rectangle to evaluate the effects of DC or HMC processed with either ROLL or HAMMER (2 × 2 factorial treatment design) on nutrient digestion. Feeding HMC decreased the amount of excreted dry matter (DM) and organic matter (OM; P ≤ 0.01) regardless of mill type, but there was a tendency (P ≤ 0.13) for an interaction between corn type and mill type for DM and OM digestibility. There was no difference between milling treatments fed as HMC (P ≥ 0.69), but the HAMMER DC diet was more digestible than the ROLL DC (P = 0.05). As expected, HMC-based diets had greater (P < 0.01) starch digestibility compared to DC, but milling method had no impact on starch digestibility (P = 0.56). There were no differences (P = 0.56) in average ruminal pH, but HMC diets had greater variance (P = 0.04) and greater area less than pH 5.6 (P = 0.05) compared to DC based diets while milling method did not impact either (P > 0.33). Processing HMC with a roller mill improved G:F compared to processing with a hammer mill, but had little effect when corn was fed as dry corn or HMC:DC blend. Furthermore, feeding cattle HMC compared to DC increases nutrient digestibility, but milling method had little impact.

Формирование интерметаллического покрытия Ni-=SUB=-3-=/SUB=-Al холодным газодинамическим напылением механически обработанной в планетарной мельнице порошковой смеси Ni-Al

The features of the formation of an intermetallic Ni3Al coating by cold spraying of a Ni–Al powder mixture mechanically treatment in a planetary mill and prepared in a V-shaped mixer are presented. It is shown that the powder deposition efficiency is 1.5 times higher when coatings are obtained from a mechanically treated powder mixture of Ni and Al components. Subsequent high-temperature treatment in the furnace chamber creates a condition for the formation of an intermetallic compound of the Ni-Al system of various stoichiometric proportions.

Utilization of concrete waste from demolition sites in pavement subgrade

The direct use of recycled waste concrete (RWC) is difficult as the demolished concrete shows large variation of raw materials and higher rate of water absorption due to the porosity of the lumps. Owing to such reasons, the utilization of the RWC is difficult for structural applications; however, it may be interesting to explore the feasibility of using RWC in non-structural applications such as subgrade layer of pavements. In this research work, the demolished concrete has been recycled with nominal crushing treatment in a ball mill and separated as fine powder, small to medium size aggregates. The soil samples have been prepared consisting soft clay (SC) type subgrade soil with all three forms of RWC in equal proportions. The SC has been replaced from 0% to 70% by weight with the blended RWC. Tests for the subgrade characterization namely California Bearing Ratio (CBR) values, dry density, moisture content, and plate load tests have been conducted. Under all test conditions, the addition of the RWC into the SC soil showed improvement at a given fraction of replacement. The work supported the feasibility of the utilization of the RWC for preparing the subgrade layer for the pavements and promoting the sustainability of the waste concrete in the civil engineering applications.

Manufacturing technology of small-sized profile parts

The paper considers the issues of processing small-sized profile parts, in particular, micro milling on a contour-milling machine with CNC. The technology of fixing small parts due to the adhesive connection is proposed. Calculations of the adhesive joint are carried out taking into account the coefficient of safety margin for shear resistance. Experimental studies of contour milling processing were also carried out, as a result of which recommendations were formulated on the choice of processing modes for copper alloy 99.5%Cu. The tool breakage limit is determined under the specified processing conditions. The possibility of using a combination of micro milling and electroerosion treatment is considered.

Solubilization of sulfuric acid lignin by ball mill treatment with excess amounts of organic compounds.

In order to improve the solubility of sulfuric acid lignin (SL) in N,N-dimethylformamide (DMF), dry ball milling with excess amounts of additives such as l-tartaric acid was performed. Although the ball-milled SL without any additives was not soluble in DMF, when the SL was ball milled with an excessive amount of l-tartaric acid (the concentration of SL to be 0.1%), the dispersion and solubility of SL in DMF detected by the dynamic light scattering was greatly improved. Furthermore, the DMF solution showed clear photoluminescence, indicating that the distance between luminophores was modulated due to dispersion on the nanoscale. The structural analysis of the isolated lignin showed a decrease in molecular weight and the introduction of carboxylic acid groups. In other words, the introduction of hydrophilic functional groups into the lignin and simultaneously decrease in the molecular weight due to the cleavage of lignin linkages is considered to result in good dispersion in DMF on both the micro and macro scales. Similar effects were observed with the other chemicals containing several hydrophilic groups such as citric acid, d-glucose, and polyacrylic acid. Furthermore, this method is applicable to various lignins other than SL, and it is expected to utilize unused lignin resources.

Physicochemical properties, phenolic content and in vitro digestion profile of Chinese black rice (Oryza sativa L.).

Yangxian black rice, as one of the ancient Chinese black rice varieties, is widely planted in the Yangxian area of China. This study investigated the physicochemical properties, phenolic content and in vitro digestion profile of Chinese black rice under gradient milling treatment. The chemical composition, color, pasting and thermal properties of black rice with different milling degrees were comprehensively compared. In vitro digestion analysis indicated that cooked rice flour had higher rapidly digestible starch (RDS) and lower resistant starch (RS) contents compared with the uncooked one. Besides, all cooked black rice samples exhibited high predicted glycemic index (pGI) value and whole black rice showed a lower pGI than refined rice. The microstructure and the abundance of phenolic compounds in the solid matrix during different treatments or digestion stages were observed by CLSM. Furthermore, a total of 102 phenolic constituents were absolutely quantified by targeted metabolomics techniques. Methanol extraction and moderate cooking treatment contributed to the release of phenolic compounds from the solid matrix of whole black rice. Besides, compared to the gastric digestion stage, the transition in the intestinal environment caused a decrease in the majority of the analyzed polyphenols. Identifying the phenolic constituents was favorable for a better elucidation of the chemical basis of the function and nutritional value of Chinese black rice.

Remarkable synergy between sawdust biochar and attapulgite/diatomite after co-ball milling to adsorb methylene blue.

Biochar has been recognized as a promising sustainable adsorbent for removing pollutants from wastewater. In this study, two natural minerals, attapulgite (ATP) and diatomite (DE) were co-ball milled with sawdust biochar (pyrolyzed at 600 °C for 2 h) at ratios of 10-40% (w/w) and examined the ability of methylene blue (MB) to be removed from aqueous solutions by them. All the mineral-biochar composites sorbed more MB than both ball milled biochar (MBC) and ball milled mineral alone, indicating there was a positive synergy in co-ball milling biochar with these minerals. The 10% (w/w) composites of ATP:BC (MABC10%) and DE:BC (MDBC10%) had the greatest MB maximum adsorption capacities (modeled by Langmuir isotherm modeling) and were 2.7 and 2.3 times that of MBC, respectively. The adsorption capacities of MABC10% and MDBA10% were 183.0 mg g-1 and 155.0 mg g-1 at adsorption equilibrium, respectively. These improvements can be owing to the greater content of oxygen-containing functional groups and higher cation exchange capacity of the MABC10% and MDBC10% composites. In addition, the characterization results also reveal that pore filling, π-π stacking interactions, hydrogen bonding of hydrophilic functional groups, and electrostatic adsorption of oxygen-containing functional groups also contribute prominently to the adsorption of MB. This, along with the greater MB adsorption at higher pH and ionic strengths, suggests the roles in MB adsorption was an electrostatic interaction and an ion exchange mechanism. These results demonstrate that mineral-biochar composites prepared by co-ball milling treatment were promising sorbents of ionic contaminants for environmental applications.

The effects of dry grinding and wet grinding on synthesizing iodosodalite

How to dispose of radioactive iodine waste in a green and safe way has become a hot spot for research institutions around the world. In this study, we mainly compare the effects of wet grinding - hydrolysis transformation - sintering (wet grinding) and dry grinding - cold pressing - sintering (dry grinding) on the synthesis of iodosodalite. The analysis results show that the particle size of 4A zeolite treated by wet grinding for 2.5 ​h is approximately 5.5 ​μm. The results of in situ XRD, infrared spectroscopy, and in situ Raman show that the effect of wet grinding and refining treatment is more obvious for iodosodalite synthesis at 900 ​°C. TEM-EDS shows that the morphology of iodosodalite prepared by the wet method is more intact. Based on the above results, it is demonstrated that the wet milling treatment method is more favorable for the synthesis of iodosodalite.

A novel Fe-PTFE magnetic composite prepared by ball milling for the efficient degradation of imidacloprid: Insights into interaction mechanisms based on ultrasonic piezoelectric catalysis

In this study, a novel magnetic poly (tetrafluoroethylene, PTFE) (Fe@PTFE) piezoelectric catalytic material was successfully prepared by a simple ball milling treatment. The prepared piezoelectric catalytic material Fe@PTFE exhibited excellent catalytic performance under the activation of ultrasonic (US) and realized the efficient degradation of imidacloprid (IMI) at low concentrations in an aqueous environment. It was demonstrated by various characterization methods that Fe0 was successfully loaded onto PTFE particles (1–15 μm) by ball milling. The US/Fe@PTFE system exhibited superior IMI degradation efficiency (99 %) and degradation rate (7.81× 10−2 min−1) under ultrasonic polarization with high efficiences of IMI degradation after five cycles. In addition, the system maintained excellent removal efficiencies in the real water matrixes. The mechanism study demonstrated that Fe@PTFE generated a variety of reactive oxygen species (•OH, 1O2 and O2•-) and H2O2 under the irradiation of US, and the production of H2O2 provided the conditions for the continuation of the Fenton-like reaction. Furthermore, the presence of O2•- in the system enhanced the recycling efficiency of Fe(III) and Fe(II), which further enhanced the degradation efficiency of the Fenton-like process. This study provides a novel perspective on a PTFE-based ultrasonic piezoelectric catalytic system for the efficient removal of organic pollutants in the environmental field.

Synthesis of powder functional composite materials containing g-C3N4, β-Si3N4 and Si2N2O phases

The article discusses the technology of alloying carbon material with Taunite-M nitrogen and silicon, which combines mechanochemical synthesis in a spherical planetary mill and multistage heat treatment up to 1100°C. The aim of the work is to obtain a new material based on nanostructured carbon raw materials with improved physical and chemical properties as a result of the formation of new phases due to the introduction of silicon and melamine into the initial charge as a source of nitrogen. The phase composition of the obtained samples was studied by X-ray diffractometry, the porosity and distribution of chemical elements in the samples of the obtained material were evaluated using X-ray tomography and scanning electron microscopy. Based on the results obtained, conclusions are formulated about the formation of phases of graphite-like carbonitride, nitride and oxynitride of silicon in a thermally stable nanocarbon material.

Effects of the dose and depth on the microstructural characteristics of proton-irradiated austenitic 316 stainless steel

Type 316 austenitic stainless steel was irradiated at 360 °C with 2 MeV protons to doses up to 6.0 displacements per atom at a depth of approximately 10 μm and the various effects of proton irradiation on the irradiation defects and microstructural changes were characterized using transmission electron microscopy. The irradiation defects produced by protons consisted of Frank loops, network dislocations, voids and nanotwins. The size and the density of the irradiation defects increased depending on the increase of the dose. Frank loops, dislocations and nanotwins were found mainly in regions irradiated at a low dose, whereas voids were dominant in regions near the damage peaks. The evolution of typical irradiation defects changed according to the irradiation depth, in agreement with the characteristics of the dose variation depending on the depth. This behavior during the production of distinct irradiation defects according to the irradiation depth appears to be an intrinsic characteristic of any type of ion irradiation. A simple and effective method of preparing TEM specimens to remove chemically the surface damage layers induced by a high-energy focused ion beam and/or low-energy ion milling treatments is suggested. • Frank loops, dislocations and voids induced by proton irradiation were investigated. • Nanotwins were formed in austenitic 316 stainless steel by proton irradiation. • Evolution of typical irradiation defects changed according to the irradiation depth. • Chemical polishing method to remove FIB- and IM-induced damage layers was suggested.