Particle Size Of Powder Research Articles

Preparation and evaluation of a functional effervescent powder based on inclusion complexes of orange oil and β-cyclodextrin derivatives

Flavoured functional effervescent powders are becoming increasingly popular by consumers due to their health benefits and easy dissolution. In present study, orange flavoured effervescent powders having functional properties were prepared. Orange oil (O) was blended with different essential oils (EOs) that have high antioxidant activity. The orange oil and the O-EOs blends were subjected to odour sensory evaluation, gas chromatography-mass spectrometry (GC-MS) analysis and evaluation of radical scavenging activity. Combinations of two water soluble β-cyclodextrin polymers, 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) and epichlorohydrin-β-cyclodextrin (EPI-β-CD), were prepared at different molar ratios (3:1 and 1:3, F1 and F2, respectively). The O-EOs blends that showed the highest antioxidant activities and best odour qualities were encapsulated with F1 and F2, separately. The orange flavoured inclusion complexes were prepared by freeze drying method. The particle sizes of the inclusion complex powders were in the nanoscale. Characterization of the inclusion complexes nanoparticles was performed by scanning electron microscopy (SEM), and fourier transform infrared microscopy (FT-IR). The results confirmed the successful formation of the inclusion complexes. However, inclusion complex of O-EOs (300 mg) blend with F1 (OF1cIC) showed the smallest particle size (113.90±15.90 nm), the more negative zeta potential (−27.10±1.27 mV), the highest encapsulation efficiency (95.51%) and best odour quality. Therefore, it was mixed with an effervescent powder having high acceptable characteristics. The orange flavoured effervescent powder showed superior flowability.

Processing of hydroxyapatite (HA)–Ti–6Al–4V composite powders via laser powder bed fusion (LPBF): effect of HA particle size and content on the microstructure and mechanical properties

This research study examines the influence of hydroxyapatite (HA) powder particle size and content on the processability, microstructure, and mechanical properties of the laser powder bed fusion (LPBF) fabricated Ti–6Al–4V (Ti64)-HA composites. For this purpose, various Ti64-HA composite powders were produced, and the effects of the HA particle size and content on the optical reflectance were investigated. Composite powders and the monolithic Ti64 powder (as the reference) were subjected to the LPBF process within a wide range of volumetric energy densities by varying the LPBF process parameters. Parts with the highest relative density for each material were assessed by studying their microstructure, nanohardness, and nanoindentation-derived yield strength. Results revealed that the incorporation of the highly reflective HA powder into the Ti64 slightly enhanced the reflectance of Ti64-HA composite powders over that of the monolithic Ti64 powder. The LPBF processability of the composite powders was found to highly depend on the content of the HA constituent. For any given volumetric energy density employed in this study, composites containing 1 wt%HA were crack-free. However, composite systems containing higher HA content (2.5 wt%) featured randomly distributed transgranular cracks. Addition of 1 and 2.5 wt%HA to the Ti64 resulted in a significant improvement in the nanohardness (∼30 and 75%) and yield strength (∼20 and 37%). The dominant strengthening mechanisms in composite samples were the Hall-Petch and geometrically necessary dislocations strengthening, accounting for 57–66% and 13–20% of the total yield strength improvement.

Application of Surfactant Activated Milling for Production of Nd–Fe–B Magnets by PLP Technology

The granulometric composition of Nd–Fe–B powders has been studied in detail after vibratory milling for various times both without and with the addition of siloxane. Sintered magnets were produced by the powder metallurgy method that excluded the pressing of powders. Correlations between the particle size distribution in the initial powders, microstructure of sintered magnets, and their magnetic hysteresis properties have been established. The difference in methods for estimating the size of powder particles by two methods is demonstrated. It is shown that the size distributions of powder particles and magnet grains are bimodal and are described by a superposition of two lognormal distributions.

Tribological behavior of sintered electrolytic iron‐zinc stearate added compacts

AbstractPowder metallurgy is an effective method to give near net shape to powder particles. In this paper, the influence of powder particle size, lubricant and compaction load on hardness and wear loss has been investigated as it influences the compact. Electrolytic iron powder (250 mesh to 300 mesh and 300 mesh to 350 mesh) with zinc stearate (0 weight % to 2 weight %) was used for preparing the samples. Green samples were prepared by cold compaction process at different loads (400 kN, 450 kN and 500 kN). Pre‐sintering was done at 550 °C. Taguchi′s (L18) mixed level model was used to develop the regression equation for hardness and wear loss. The maximum hardness of 79 HRB was achieved with 300 mesh to 350 mesh particle size and 500 kN compaction load. Minimum wear volume loss was observed with samples having composition of 250 mesh to 300 mesh size electrolytic iron powder at 500 kN compaction load and 1 weight % lubricant content.

Preparation and characterization of anode foil for aluminum electrolytic capacitors by powder additive manufacturing

In this paper, anode foils for aluminum electrolytic capacitors were successfully prepared using additive manufacturing technology. The effects of sintering temperature and particle size the anode foil were investigated. The results indicated that the sintering neck and particle size were the key factors to determine the electrical properties of the prepared powder foil. As the sintering temperature increased, both the porosity and the pore diameter of the anode foil decreased and the sintering neck increased, resulting in a decline of specific capacitance, while the dissipation factor did not change significantly. As the particle size of aluminum powder increased, the porosity, the pore diameter and the sintering neck of the anode foil increased. The specific capacitance of the anode foil first increased and then decreased, while the dissipation factor showed a gradual decrease. The anodic foil sintered at 630 °C and prepared with aluminum powder of 5– 6 μm had the best electrical performance.

Influence of processing parameters on joint characterization of SS 304 using microwave hybrid heating

In this study, the microwave hybrid heating process has been explored to produce optimized joints of stainless steel 304. During the experiment, IFB microwave with a 900W output power and a fixed frequency of 2.45 GHz was employed. Three process parameters: microwave welding time, powder size, and slurry weight have been investigated to see their effects on three major joint properties: tensile strength, micro-hardness and surface temperature. In order to identify the optimum settings for the process parameters to provide the best mechanical qualities for joints, Taguchi L9 was used as the design of the experiment. Microwave welding time is the most significant parameter; followed by powder particle size and slurry weight has little influence on output parameters. More welding time & slurry weight with lower powder particle size produced the best results out of the values chosen as processing parameters. The tensile strength was determined to be 499 MPa. The microhardness of the joint region resulting in a value of 452 Hv. X-ray diffraction images of joint area show the presence of nickel and carbides phases. Microstructure and SEM pictures revealed that the substrate and slurry were properly mixed. The maximum temperature on the surface of the joint was found to be 926.3°C. FESEM images of broken joint showed mixed mode of failure (ductile and brittle).

Physical models for vacuum-induced multistage atomization of high-entropy FeCoCrNiMo alloy powder for 3D printing

The atomization process of high-entropy FeCoCrNiMo alloy was tested using electrode induction gas atomization (EIGA) at different powers, pressures and rotary speeds. The modelization about the physical essence in the metal drop atomization was studied. A surface tension model, a specific surface energy model, a cooling rate model, and a solidification kinetic model of the alloy drop atomization process were built. Based on these models, the quantitative relationships between the powder particle size and process parameters during the alloy atomization were determined. Together with the results of particle size and scanning electron microscopy-based morphology of the powder obtained from EIGA under different process systems, the accuracy of the above physical models was validated.

Hot oscillatory pressure preparing low-cost FGH4096 superalloys with high performance

The low-cost and high-performance FGH4096 superalloy was prepared by replacing the high-cost fine powder particles (<51 μm) with coarse particles (>120 μm) using the hot oscillatory pressure (HOP) sintering method. The effects of powder particle size on the grain size and mechanical properties of the superalloy were investigated. The results showed that the tensile strength is 1350 MPa and the elongation is 30.4% for the HOP samples of coarse powder, the mechanical properties are higher than that of the samples prepared by the hot-press (HP) with finer powder. In addition, HOP sintering shows good inhibitory effect for the prior particle boundaries (PPB) in the powder metallurgy superalloys, for the HOP sintering providing the great driving force of particles plastic deformation. The results suggest that the coarse powder particle size with HOP sintering can achieve the better mechanical properties for the FGH4096 superalloys, thus provides a strategy for the low-cost and high-performance powder metallurgy superalloys.

Study of Surface Wettability of Mineral Rock Particles by an Improved Washburn Method.

The surface wettability of rocks in underground reservoirs affects the distribution of fluids in the reservoir, so the wettability of reservoir minerals is a key factor for crude oil recovery from reservoirs. In this paper, the wettability of quartz sand with different particle sizes in different polar solvents was determined by Washburn's capillary rise method, and the C·cos θ values were calculated first. Next, the experimentally obtained macroscopic contact angle of water on the quartz surface of 15.0° was substituted into C·cos θ to obtain a linear equation between the particle size of quartz sand and the capillary constant C. The particle sizes of oil sand and mineral powder were then substituted into the equation to obtain their capillary constants C. Then, based on the Owens-Wendt-Rabel-Kaelbe (OWRK) equation and the obtained contact angles of solvent on quartz sand, oil sand, and mineral powder, the surface free energy of quartz sand with different particle sizes is calculated as 76.09, 76.65, and 76.42 mN/m, respectively, which are close to the literature results. In addition, the surface free energy of oil sand with different particle sizes was 23.22, 23.45, and 23.63 mN/m, and the results indicated that the polarity of oil sand was low. Meanwhile, the surface free energies of kaolinite, illite, feldspar, and montmorillonite were 61.59, 32.85, 35.87, and 25.91 mN/m, respectively. By the improved Washburn method in this paper, the wettability of different solvents on the surface of reservoir rocks was investigated, and the surface free energy of specific solid particles was calculated, which is important for studying the extraction of crude oil from subsurface reservoir rocks.

Ti/β-TCP composite porous scaffolds fabricated by direct ink writing

ABSTRACT A Ti/β-TCP composite porous scaffold with a hierarchical pore structure composed of 3D printed interconnected macroscopic pores and sintered microscopic pores was prepared by direct ink writing (DIW) 3D printing technology. This method can control the extrusion of composite ink at room temperature and produce a 3D scaffold using layer-by-layer deposition. We studied the effects of the β-TCP powder particle size, β-TCP/Ti powder ratio and solid loading on the rheological properties of the ink and optimised the DIW printing process parameters. After sintering, the compressive strength and elastic modulus of the composite scaffold reached 45 MPa and 1 GPa, which is close to the strength of human cancellous bone. The cell culture experiment confirmed that the composite scaffold had better biological properties than the pure titanium scaffold. The composite scaffold has satisfactory mechanical and biological properties, meeting the requirements for orthopaedic implants.

Cost-effective way of improving the optical properties of phosphor-in-glass by adjusting the particle size of glass powder

The effects of silicate glass particle size and Y3Al5O12: Ce3+ (YAG: Ce3+) phosphor doping concentration on the optical properties of phosphor-in-glass (PiG) samples were investigated. When the average particle size of glass powder was 160, 100, 60, and 30 μm, the transmittance of silicate glass with a thickness of 0.6 mm was 68%, 78%, 62%, and 54%, respectively. With the mixing of 4 wt% YAG: Ce3+ phosphor in each component of silicate glass, the transmitted luminous flux of PiG gradually increased with the increase of transmittance, reaching a maximum of 179.5 lm. Simultaneously, we found that with the increase in transmittance, the photoluminescence (PL) intensity of PiG gradually decreased; however, the total luminous flux of PiG has independent of transmittance. When the doping concentration of YAG: Ce3+ phosphor was 4 wt%, PiG achieved a maximum efficient white light emission of 212.61 lm/W under blue laser excitation at 2.31 W. All results indicate the outstanding feasibility of the prepared YAG-PiG in high-power/high-brightness white light-emitting diodes (WLEDs).

Reverse engineering of Perseris and development of compositionally equivalent formulations

Six injectable, long-acting in situ forming implant drug products based on poly(lactide-co-glycolide) (PLGA) and N-Methyl-2-Pyrrolidone (NMP) are available on the market. However, generic products, which would likely be more affordable for patients, are not yet available. This is partially due to the unique complexity of these formulations as well as the inherent heterogeneity of PLGA and the challenges in the manufacture and characterization of this polymer. This article focuses on a comprehensive characterization of Perseris (risperidone) in situ forming implant drug product, and the development of compositionally equivalent formulations. The molecular weight (MW), lactide/glycolide (L/G) ratio, end group, blockiness and glass transition temperature (Tg) of PLGA, as well as the crystal form and particle size of risperidone powder used in Perseris were identified through reverse engineering. The dissolved/suspended drug ratio in the final implant suspension for administration, as well as the real-time drug solid state in the solidified Perseris drug depot were investigated. Two compositionally equivalent formulations prepared using customized PLGA polymers with similar properties to the Perseris PLGA showed similar in vitro release and swelling behavior to Perseris as demonstrated using a novel adapter-based dissolution method. The novelty of this dissolution method lies in its ability to control implant shape, generate reproducible data, distinguish different release phases, as well as identify formulation changes. The knowledge gained in this work and the methodology established for characterization of the implant formulations are important for implant formulation development.

Foam glass production from waste bottle glass using silicon cutting waste of loose abrasive slurry sawing as foaming agent

This study created foam glass from waste bottle glass employing silicon cutting waste (SCW) of loose abrasive slurry sawing as the foaming agent. The influence of affecting parameters, namely sintering temperature, glass powder particle size, SCW dosage, heating rate, holding time, were investigated. The produced foam glass was characterized to examine its microstructure, bulk density, compressive strength, porosity, and thermal conductivity, and was compared with that produced using silicon carbide (SiC) reagent as the foaming agent. The results indicated that under the optimal conditions of sintering temperature of 775 °C, glass powder particle size of 0.15 mm, SCW dosage of 1 wt% (the D50 of SiC in SCW was ca. 10 μm), heating rate of 10 °C/min, and holding time of 30 min, the produced foam glass had a compressive strength of 4.1 MPa, bulk density of 0.56 g/cm3, porosity of 78%, and thermal conductivity of 0.16 W/m·k; these properties meet with standards for thermal insulation materials. In contrast, using SiC reagent with a D50 of ca. 22 μm revealed 900 °C as the optimal sintering temperature, which yielded foam glass having a compressive strength of 5.4 MPa, bulk density of 0.67 g/cm3, porosity of 73%, and thermal conductivity of 0.2 W/m·k. By using SCW as the foaming agent, foam glass is able to be produced under comparatively low temperature and has favorable properties. In addition, the simultaneous waste valorization of waste bottle glass and SCW can be achieved.

Numerical simulation and experimental study of the influence of coaxial powder feeding laser cladding process parameters on gas-powder flow

Laser cladding is an advanced manufacturing technology for preparing high-performance metallurgical coatings on metal substrates that is widely used in industrial production. In order to improve the powder utilization rate and reduce the waste of powder in the coaxial powder feeding laser cladding process, the Euler–Lagrange theory was used to establish the simulation model of gas-powder two-phase flow in laser cladding. Fluent was used to simulate the powder particle size, powder particle shape factor, carrier gas flow rate, and powder feed rate under different process conditions, and the results were verified by experiments. Through analysis, under the process parameters of a carrier gas flow rate of 4 L / min and a powder feed rate of 15 g / min, the powder utilization rate was high and the surface of the cladding layer was smooth. When the particle size was 100 mesh and the particle shape factor approached 1.0, the concentration of powder focus was higher and the convergence effect was the best. The influence of powder process parameters on powder convergence was comprehensively analyzed, which is of great significance for the subsequent optimization design of nozzle and the improvement of powder utilization in the laser cladding process.

Morphological Characterization of Nicotiana tabacum Inflorescences and Chemical-Functional Analysis of Extracts Obtained from Its Powder by Using Green Solvents (NaDESs)

The production of smokeable tobacco for use in cigarettes is characterized by the production of pre-harvest and post-harvest waste, with ensuing undesirable effects on the environment. The inflorescences of tobacco after blunting, deflowering, or topping are considered pre-harvest waste and left in the field. Using green and ecofriendly solvents such as Natural deep eutectic solvents (NaDESs), these wastes could be used to obtain antioxidant molecules of interest in cosmetics. Taking into account its potential as plant matrix to obtain metabolites of commercial interest, tobacco inflorescences and inflorescence powders of different particle sizes were characterized by optic and electronic microscopy. Thus, the powdered inflorescences were extracted with four conventional solvents, i.e., distilled water (DW), acetone: distilled water (AW), ethanol 70° (EW), methanol (Me), and five NaDESs, i.e., lactic acid: sucrose (LAS), lactic acid: sucrose: distilled water (SALA), fructose: glucose: sucrose: distilled water (FGS), choline chloride: urea: distilled water (CU), and citric acid: propylene glycol (CAP). Among the tested NADESs, SALA was the most promising solvent; higher extraction yields of total phenolic compound (3420.0 ± 9.4 µg GAE/mL) than conventional solvents were attained and it was the only selective solvent to phenolics. CU was the best solvent for flavonoids and alkaloids extraction (215.3 ± 3.2 µg QE/mL and 392.3 ± 8.0 µg ACE/mL, respectively). All extracts showed antioxidant activity. A heatmap with dendrogram and main component analysis showed that acid-based NaDESs are grouped together, this group being the one with the best performance in H2O2 scavenging. The extracts obtained with green solvents could be used directly in cosmetic formulations as antioxidant ingredients because both tobacco flower oil and flower extracts are listed in the cosmetic ingredients database as non-toxic products. Additionally, the demand for sustainable ecological cosmetics is growing. In this sense, NaDESs represent an opportunity to develop innovative extracts with unique phytochemical fingerprints and biological activities.

A mechanically durable induction heating coating with desirable anti-/de-icing performance

ABSTRACT The anti-/de-icing technology based on induction heating offers significant advantages regarding fast heating, high efficiency, safety and environmental protection. However, the reported methods require the modification of base materials, which lacks universal applicability. Here, a universal and facile anti-/de-icing method is proposed based on induction heating. The durable induction heating coating was prepared by one-step spin coating with micron-sized nickel powder, epoxy resin and silicone resin. The induction heating ability of this coating was investigated by adjusting the proportion of composition, particle size and thickness. An optimal induction heating ability was achieved with the mass ratio of nickel powder and resin, particle size of nickel powder and coating thickness being 1.5, 7 μm and 1070 μm, respectively. We further show this coating can be applied for anti-/de-icing, demonstrated by its excellent de-/anti-icing performances. Finally, the mechanical durability of the coating was verified by the tape peel and sandpaper friction.

Light Weight MnTiAlNiFe High-Entropy Alloy (LWHEA) Fabricated by Powder Metallurgy Process: Mechanical, Microstructure, and Tribological Properties

The present work is focused on the development of lightweight high entropy alloy (LWHEA) using a powder metallurgy process. The primitive powders of manganese (Mn), titanium (Ti), aluminum (Al), nickel (Ni), and iron (Fe) with a purity of ∼ 99.5 % and particle size in the range of 40 to 70 µm were considered as a raw material for the synthesis of present LWHEA. The elemental powders at an equal molar ratio were mechanically alloyed (MA) in a high-energy ball milling for 28 hrs. The MA powders were then cold compacted using 500 MPa pressure, followed by sintering at 900 °C in an inert atmosphere to produce a bulk cylindrical sample of 8 mm diameter and 8 mm height. The average particle size of the milled powders was measured by FESEM image analysis, while the crystal size of the milled powders was predicted from the XRD peak broadening followed by full-width half maximum (FWHM) peak profile calculation using the Hall-Williamson method. The BCC structure, along with intermetallic phases, was identified in the sintered bulk LWHEA of MnTiAlNiFe. Some intermetallic phases act as reinforcement in the alloy. The EDX analysis of MA powder revealed that all the elemental powders were distributed homogeneously to form a solid solution of LWHEA powder. The deformation behavior of the sintered MnTiAlNiFe LWHEA was studied by analyzing the loading–unloading curve of micro indentation. A remarkable improvement in the hardness values (microhardness ∼ 7.382 GPa and Martens hardness ∼ 3.09 GPa at 3 N load) was observed compared to conventional lightweight metallic alloys. The investigation of the wear behavior of the bulk MnTiAlNiFe LWHEA samples carried out in a Universal Tribometer coupled with a 3D optical profilometer predicts the load-dependent coefficient of friction of the sample.

Technology and principle of improving solubility of Dioscoreae Rhizoma formula granules based on powder modification

The powder modification technology was used to improve the powder properties and microstructure of Dioscoreae Rhizoma extract powder, thereby solving the problem of poor solubility of Dioscoreae Rhizoma formula granules. The influence of modifier dosage and grinding time on the solubility of Dioscoreae Rhizoma extract powder was investigated with the solubility as the evaluation index, and the optimal modification process was selected. The particle size, fluidity, specific surface area, and other powder properties of Dioscoreae Rhizoma extract powder before and after modification were compared. At the same time, the changes in the microstructure before and after modification was observed by scanning electron microscope, and the modification principle was explored by combining with multi-light scatterer. The results showed that after adding lactose for powder modification, the solubility of Dioscoreae Rhizoma extract powder was significantly improved. The volume of insoluble substance in the liquid of modified Dioscoreae Rhizoma extract powder obtained by the optimal modification process was reduced from 3.8 mL to 0 mL, and the particles obtained by dry granulation of the modified powder could be completely dissolved within 2 min after being exposed to water, without affecting the content of its indicator components adenosine and allantoin. After modification, the particle size of Dioscoreae Rhizoma extract powder decreased significantly, d_(0.9) decreased from(77.55±4.57) μm to(37.91±0.42) μm, the specific surface area and porosity increased, and the hydrophilicity improved. The main mechanism of improving the solubility of Dioscoreae Rhizoma formula granules was the destruction of the &quot;coating membrane&quot; structure on the surface of starch granules and the dispersion of water-soluble excipients. This study introduced powder modification technology to solve the solubility problem of Dioscoreae Rhizoma formula granules, which provided data support for the improvement of product quality and technical references for the improvement of solubility of other similar varieties.

Powder Spreading Mechanism in Laser Powder Bed Fusion Additive Manufacturing: Experiments and Computational Approach Using Discrete Element Method.

Laser powder bed fusion (LPBF) additive manufacturing (AM) has been adopted by various industries as a novel manufacturing technology. Powder spreading is a crucial part of the LPBF AM process that defines the quality of the fabricated objects. In this study, the impacts of various input parameters on the spread of powder density and particle distribution during the powder spreading process are investigated using the DEM (discrete element method) simulation tool. The DEM simulations extend over several powder layers and are used to analyze the powder particle packing density variation in different layers and at different points along the longitudinal spreading direction. Additionally, this research covers experimental measurements of the density of the powder packing and the powder particle size distribution on the construction plate.

Study on the quasi-isentropic model for aluminized explosive driving the cylinder in the direction perpendicular to detonation wave propagation

A cylinder test was designed for the CL-20-based aluminized explosives to study the influence of aluminum (Al) powder properties on the explosives' metal driving performance in the direction perpendicular to detonation wave propagation. The research results showed that: in the direction perpendicular to detonation wave propagation, as the Al powder particle size became larger (in the range of 2–43 μm), the metal driving performance of the explosives grew stronger; the CL-20-based explosive containing 25% Al was much less capable of accelerating the metal than the formulation containing 15% Al. Considering the two-dimensional flow characteristics of the detonation products in the radial and axial directions as the aluminized explosive expands and drives the cylinder, a quasi-isentropic theoretical model for the aluminized explosive driving the cylinder was proposed. In the model, the calculation methods for the variations of the cylinder expansion velocity, Al reaction degree, and detonation product parameters with time, axial space, and radial space were developed. According to the experimental data of the cylinder test, the correctness of the proposed quasi-isentropic theoretical model was verified; the variation laws of the physical parameters, such as the pressure and temperature of the detonation products under different radial distributions in the cylinder with time and axial positions, were calculated. It was found that the pressure and temperature of the detonation products in the non-inner-wall place of the cylinder were significantly higher than those on the inner wall of the cylinder at the same axial position; the pressure and temperature of the detonation products on the inner wall decreased rapidly at the early timeframes; as the Al reaction proceeded, the pressure gradually turned to a constant value, and the temperature dropped slowly; for the CL-20-based explosives with 15% Al, the temperature of the detonation products in the non-inner-wall place rose slightly at first and then decreased slowly; for the formulation with 25% Al, the temperature of the detonation products in the non-inner-wall place kept rising at a small rate.