Powder Mixtures Research Articles

The Synthesis and Analysis of the Cytotoxicity of Al2O3-Supported Silver Nanoparticles Prepared by the Plasma Chemical Process Initiated by Pulsed MW Radiation in the Al2O3–Ag Powder Mixtures

The Synthesis and Analysis of the Cytotoxicity of Al2O3-Supported Silver Nanoparticles Prepared by the Plasma Chemical Process Initiated by Pulsed MW Radiation in the Al2O3–Ag Powder Mixtures

Study of the Absorption of the Pulsed Microwave Radiation of a Gyrotron in an Al/Al2O3 Powder Mixture

Study of the Absorption of the Pulsed Microwave Radiation of a Gyrotron in an Al/Al2O3 Powder Mixture

Precursor-Engineered Volatile Inks Enable Reliable Blade-Coating of Cesium-Formamidinium Perovskites Toward Fully Printed Solar Modules.

Reliable fabrication of large-area perovskite films with antisolvent-free printing techniques requires high-volatility solvents, such as 2-methoxyethanol (2ME), to formulate precursor inks. However, the fabrication of high-quality cesium-formamidinium (Cs-FA) perovskites has been hampered using volatile solvents due to their poor coordination with the perovskite precursors. Here, this issue is resolved by re-formulating a 2ME-based Cs0.05FA0.95PbI3 ink using pre-synthesized single crystals as the precursor instead of the conventional mixture of raw powders. The key to obtaining high-quality Cs-FA films lies in the removal of colloidal particles from the ink and hence the suppression of colloid-induced heterogeneous nucleation, which kinetically facilitates the growth of as-formed crystals toward larger grains and improved film crystallinity. Employing the precursor-engineered volatile ink in the vacuum-free, fully printing processing of solar cells (with carbon electrode), a power conversion efficiency (PCE) of 19.3%, a T80 (80% of initial PCE) of 1000h in ISOS-L-2I (85°C/1Sun) aging test and a substantially reduced bill of materials are obtained. The reliable coating methodology ultimately enables the fabrication of carbon-electrode mini solar modules with a stabilized PCE of 16.2% (average 15.6%) representing the record value among the fully printed counterparts and a key milestone toward meeting the objectives for a scalable photovoltaic technology.

A comparative study of electric current-assisted and conventional sintering of Inconel 718 superalloy

AbstractIn this study, In718 powder mixtures prepared from elemental powders following stoichiometric composition and supplied as a commercial product were produced by conventional powder metallurgy (1300 °C/4 h) and electric current-assisted sintering (ECAS)(1700-2300A/10 min) methods and followed by a double-aging heat treatment. The characterization studies determined that the best results were the sample produced by the ECAS method using the elemental powder mixture. The targeted precipitate γ′, γ″, and δ phases were obtained after the heat treatment, and a hardness value of 344 ± 41 HV0.5 and a relative density of 98.96% were achieved. The sample preserved its surface integrity by exhibiting high corrosion resistance from hot corrosion studies in the temperature range of 650–850 °C and NaSO4 + 60%V2O5 environment. The corrosion rate of the sample, which was subjected to electrochemical corrosion tests in 3.5% NaCl and 10% NaNO3 solutions, was determined as 45.59 mpy and 10.56 mpy, respectively.

Experimental optimization of CuO and MgO hybrid nanoparticle reinforcement ratios to enhance fatigue life of GFRP composites

AbstractThis study investigated the optimization of CuO and MgO nanoparticle reinforcement ratios within glass fiber‐reinforced polymer (GFRP) composites, and it examined the impact of the hybrid mixture of oxide powders on the mechanical properties of the GFRPs. The study aims to improve the mechanical properties of GFRPs by combining these two powerful nanofillers in various weight ratios to find the best combination to obtain the best fatigue life. Tensile‐tensile fatigue tests were conducted on 25 samples containing hybrid CuO and MgO nanoparticles ranging from 0.0 to 0.8 wt% in 0.2% increments. The test was conducted using a computer‐controlled servo‐hydraulic fatigue device. It was found that the GFRP composite reinforced with hybrid nanoparticles improved the fatigue life. The CuO proportion in the composites partially increased the brittleness properties, while the MgO proportion partially increased the stiffness according to the results. It was found that 0.6 wt% MgO–0.4 wt% CuO and 0.2 wt% MgO–0.6 wt% CuO GFRP composites demonstrated the highest fatigue life yielding at the 39.5k, and 13.7k cycle at 70%, and 80% load level, respectively. The best fatigue life was yielded at the 128k cycle with the 0.4 wt% MgO and 0.6 wt% CuO sample at the 60% load level. According to experimental hysteresis energy loss, 0.4 wt% MgO–0.2 wt% CuO GFRP composite was found to have the highest energy loss. The energy loss increased by approximately 51% in this composite compared to the non‐reinforced composite. The fracture surfaces of a fatigue sample were shown with the SEM image.Highlights The GFRP composites were produced by combining MgO and CuO as a hybrid reinforcement. Analyzed fatigue life using hysteresis curves and S–N graphs. The fatigue life of GFRP composites was improved with hybrid nanofiller content. As compared to separate reinforcements with CuO or MgO, the hybrid nanoparticle reinforcement enhanced fatigue life more.

The Structural Examination of Fe/(Cu/Nb)/MgB2 Multifilament Wires During Cold Forming Process

In this study, we have successfully produced a Fe-sheathed 6+1 multifilament wire using Cu/Nb/MgB2 monocore wires. The mono filament wire was prepared using Mg+2B powder mixture by powder-in-tube method without any intermediate heat treatment. The powder mixture of the amorphous nano boron (PVZ Nano Boron, purity of 98.5%, particle sizes < 250 nm) and high purity Mg powder (PVZ Mg, purity of 99%, particle size 74µm) were used. The multifilament wire was produced using groove rolling and cold drawing machines. The geometrical form of the filaments was examined using wire pieces taken from the wire at different steps throughout the production process. Finally, the multifilament wires produced in two different diameters of 1.02 mm and 0.82 mm were investigated in terms of filament uniformity, crack formation, surface roughness, and electrical transport properties. The structural examination was done on Nb filaments after the Fe and Cu sheaths were etched using HCl and HNO3 solution. The I – V measurements of the multifilament wires heat treated at 650 °C for 15, 30, 45, 60, and 240 minutes, and 700 °C for 60 minutes were carried out for the applied current up to 1 A at 25 K under various external magnetic field.

Industrial Ecotechnological Assessment of Lime as a Sustainable Substitute for Desulfurization of Cast Iron

AbstractThis study comprehensively assesses the ecotechnological consideration and perspective of implementing a lime-based desulfurization process in the cast iron industry to replace the utilization of magnesium partially. By adopting an injection process to introduce the lime powder into molten cast iron, this research elucidated that the new alternative concept can successfully be integrated with daily operations without any disparities in cast iron quality, as proved by the production of cast iron products with vermicular graphite. A mixture of lime powder and carbon was utilized, and it was substantiated that the aim of a sulfur content lower than 0.015% can be reliably achieved. Furthermore, an ecological analysis was also conducted to justify the possible environmental advantages. The results indicated that considering the cradle-to-gate approach, the maximum amount of CO2eq connected to the lime-based desulfurization is approximately 43 g for 1 kg of desulfurized cast iron. This amount of calculated emission is still expected to be lower than the minimum calculated emission associated with the magnesium-based process, which can reach an amount of 76 g for a similar functional unit. Graphical Abstract

Machining Performance Analysis of Ti6-Al-4V in Powder-Mixed EDM Using Green Dielectric Oil

In this investigation, the factors were oil type ([Formula: see text]), powder type ([Formula: see text]), and powder concentration ([Formula: see text]) level, and the machining parameters were the voltage (V), capacitance (pf), pulse-on time ([Formula: see text]), and pulse-off time ([Formula: see text]). The output parameters were the material removal rate (MRR), and tool wear rate (TWR). Three types of oils and powders, along with their respective particle concentrations, were selected for this experiment. Neem, Karanja, and sesame oils were mixed with aluminum oxide (Al2O3), chromium (Cr), and nickel (Ni) powder at 4, 6, and 8[Formula: see text]gm/l, respectively, using an overhead stirrer to investigate the conditions under which the green oil powder mixed mixture yielded a higher MRR and lower TWR during the micro-EDM process of titanium alloy (Ti-6Al-4V) using a 0.8[Formula: see text]mm tungsten carbide (WC) tool with fixed machining parameters (240[Formula: see text]V, 100[Formula: see text]pf, 20[Formula: see text][Formula: see text]s [Formula: see text], and 5[Formula: see text][Formula: see text]s [Formula: see text]). All the powders used in this experiment had a 32-micron (450 mesh) size. The Taguchi L[Formula: see text] orthogonal array and grey relational analysis methods were used to design and optimize the input process parameters for both responses. SEM, optical microscopic analysis, and EDS analysis were performed to examine the surface morphology, characteristics of the WC tool, and elemental composition of both the tool and the workpiece material. The optimum conditions for Karanja oil with a Cr powder mixture concentration of 4[Formula: see text]g/l resulted in higher MRR and lower TWR. However, machining with neem and sesame oils resulted in higher TWR and lower MRR.

Preparation of W-Ni-Cu Alloy Powder by Hydrogen Reduction of Metal Oxides

The effect of powder processing on the microstructure and sinterability of the heavy alloy W-Ni-Cu was investigated. The heavy alloy powders were prepared by the ball milling and hydrogen reduction of metal oxide powders. As the milling time increased, the size of the powder mixture decreased and at 5 h of milling was found to be about 2.5 μm. Microstructural analysis revealed that the powder mixture was changed to W and NiCu alloys with an average particle size of about 200 nm after hydrogen reduction at 800°C for 2 h. The reduction kinetics of the oxide powder mixture was evaluated by the amount of peak shift with heating rates using TGA in a N<sub>2</sub>-10% H<sub>2</sub> atmosphere. The activation energy of the reduction reaction, calculated from the slope of the Kissinger plot, was measured to be 42.8 kJ/mol for CuO, 57.9 kJ/mol for NiO, and 50.1~112.6 for kJ/mol WO<sub>3</sub>. The relative densities of the heavy alloy sintered at 1100oC and 1200oC using oxide powder were 81.4% and 96.0%, while the specimen using metal powder as a raw material showed a relatively low value of 67% and an inhomogeneous microstructure. It was explained that the changes in sintered microstructure with different powder synthesis methods are mainly due to the powder characteristics, such as the size of the particles of the initial mixed powder.

Recovery of residual polyamide (PA12) from polymer powder bed fusion additive manufacturing process through a binder jetting process

Purpose This study aims to propose the reuse of PA12 (powder) in another AM process, binder jettiinng, which is less sensitive to the chemical and mechanical degradation of the powder after multiple cycles in the laser system. Design/methodology/approach The experimental process for evaluating the reuse of SLS powders in a subsequent binder jetting process consists of four phases: powder characterization, bonding analysis, mixture testing and mixture characteristics. Analyses were carried out using techniques such as Fourier Transform Infrared Spectroscopy, scanning electron microscopy, thermogravimetric analysis and stress–strain tests for tension and compression. The surface roughness, color, hardness and density of the new mixture were also determined to find physical characteristics. A Taguchi design L8 was used to search for a mixture with the best mechanical strength. Findings The results indicated that the integration of waste powder PA12 with calcium sulfate hemihydrate (CSH) generates appropriate particle distribution with rounded particles of PA12 that improve powder flowability. The micropores observed with less than 60 µm, facilitated binder and infiltrant penetration on 3D parts. The 60/40 (CSH-PA12) mixture with epoxy resin postprocessing was found to be the best-bonded mixture in mechanical testing, rugosity and hardness results. The new CSH-PA12 mixture resulted lighter and stronger than the CSH powder commonly used in binder jetting technology. Originality/value This study adds value to the polymer powder bed fusion process by using its waste in a circular process. The novel reuse of PA12 waste in an established process was achieved in an accessible and economical manner.

Additively manufactured low-gradient interfacial heterostructured medium-entropy alloy multilayers with superior strength and ductility synergy

Metallic additive manufacturing (AM) offers near net-shape fabrication but often results in insufficient strength and/or ductility due to voids or cracks, coarse initial crystalline microstructure, insufficient volume fraction of precipitates and yet post-AM strengthening/toughening methods non-destructive to shape are generally lacking. Here, we report a laser-directed energy deposited (L-DED) medium entropy alloy (MEA) with a heterostructure (HS) comprising alternate layers of solid-solution and intermetallic-dispersed MEA that possess ultimate tensile strength of 1132.8 MPa and elongation of 50.6 %, corresponding to strength-ductility synergy higher than other medium- or high-entropy alloys reported. The multilayers were produced from a dual source of CoCrNi MEA powder and a powder mixture of the same MEA, Al and Ti with stoichiometry (CoCrNi)86Al7Ti7, and the remarkable strength-ductility synergy is achieved only after post-L-DED heat treatment, which causes Al and Ti to diffuse across the layers to form a low-gradient HS. The significant back stress due to the HS contributes to the high strength, while the high ductility results from a high strain-hardening rate suppressing necking. This study demonstrates the concept of using AM not just as a near net-shape fabrication method but also a unique tool to produce low-gradient HSs with superb mechanical properties, via the use of multiple powder sources combined with suitable shape-preserving post-fabrication heat treatment.

Bi-layer cBN-based composites reinforced with oxide and non-oxide microfibers of refractory compounds

Research into new composites utilizing cubic boron nitride (PcBN) shows promise for enhancing cutting tool performance. The unique properties of these materials stem from the addition of microfibers made of refractory compounds to their structure. This study looks at developing two-layer composites based on cBN group BL, reinforced with SiCw and Al2O3w microfibers. The goal is to improve tool stability when cutting hardened steels with impact loads. PcBN composite samples were made by sintering a mixture of cBN powder with bundles and microfibers under 7.7 GPa pressure. Bond material selection was based on analyzing the relationship between Poisson's ratio (η) and plasticity parameter (G/B). The density, Young's modulus, Poisson's ratio, and hardness of the composites were determined, and the microstructure of samples with TiCN bond was studied. Tool-life tests were conducted on two-layer cutting inserts made of PcBN reinforced with SiCw and Al2O3w microfibers during the machining of hardened KhVG steel (HRC 55) under impact loads at cutting speeds of 100 and 200 m/min.

Structural and optical properties of highly Ag-doped TiO2 thin films prepared by flash thermal evaporation

The present study investigates the structural and optical properties of silver (Ag)-doped titanium dioxide (TiO2) thin films prepared via flash thermal evaporation using TiO2 and Ag powders mixture at various mass ratios. The crystallinity and surface morphology of the films were studied by varying the percentage of Ag content. Structural properties were characterized using X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM), while optical properties were assessed through optical transmission spectra analysis. Results indicate that Ag doping enhances crystallinity, as evidenced by XRD and Raman spectroscopy, and induces surface plasmon resonance (SPR) absorption attributed to Ag nanoparticles. SEM micrographs reveal agglomerated silver particles on the film surface, confirming Ag diffusion during annealing. Surface analysis through Secondary Ion Mass Spectrometry (SIMS) measurements illustrated the diffusion of Ag within the TiO2 samples and its subsequent accumulation at the surface. We have suggested that the crystallization observed in the evaporated TiO2-Ag thin films may primarily result from the thermal diffusion of Ag metal rather than the annealing process alone. Optical transmission spectra demonstrate a shift in the absorption edge towards the visible region with increasing Ag concentration, indicating enhanced light absorption properties.

Response of laying hens fed diet supplemented with a mixture of olive, laurel, and rosemary leaf powders: Metabolic profile, oxidative status, intestinal histomorphology, and egg quality

This study aimed to evaluate the effects of a mixture of olive, laurel, and rosemary leaf powders, on the oxidative state, biochemical, immune, intestinal morphophysiological parameters, and egg quality of laying hens. One hundred Lohmann Brown hens (28 weeks old) were equally assigned to two groups (n. 50) corresponding to a basal control diet (CON) or the diet supplemented with 6 g/kg feed of leaf powder mixture (LPM) containing olive, laurel, and rosemary leaves (1:1:1), for 60 days. Oxidative status, biochemical indices, immune response, cecal short chain fatty acids (SCFAs), intestinal morphological characteristics, and some egg traits were evaluated at the end of the experiment. The results indicated that LPM improved (P < 0.05) the oxidative status (TOS, ROMs), the immune system (IL-6, IL-1β, and TNF-α), the total protein and HDL cholesterol content, whereas it decreased (P < 0.05) total cholesterol and LDL cholesterol. Aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase were significantly (P < 0.05) lower in the LPM than in the CON group. A significant increase (P < 0.05) in SCFA content in the caecum, as well as in villi height and crypt depth in both duodenum and ileum of LPM-treated hens, was observed. Egg quality parameters were not influenced (P > 0.05) by LPM. These findings indicate that LPM can be considered a candidate as an antioxidant ingredient for functional food in laying hens.

Nucleation mechanism, particle shape and strengthening behavior of (Ti, Nb) (C, N) particles in Fe-based composite coatings by plasma spray welding

This study aimed to determine the nucleation mechanism, particle shape, and strengthening behavior of (Ti, Nb) (C, N) particles in Fe-based composite coatings. In this study, an in-situ technique combined with a plasma spray welding process was proposed to obtain a coating with in-situ (Ti, Nb) (C, N) particles. Composite coatings were successfully prepared on low-alloy steel by plasma spray welding using a mixture of Fe-based, Ti and Nb powders. N gas was used to provide the N atoms. The microstructural analysis results indicated that the reinforced particles transformed from irregular dendritic into massive and spherical particles, and then into spherical and lath particles, as the atomic ratio of Ti/Nb decreased. During solidification, TiN nucleated preferentially and Ti (C, N) particles were formed sequentially. Subsequently, NbC nucleated and grew with Ti (C, N) as its core, and (Ti, Nb) (C, N) particles were formed at the end. The microhardness values of these composite coatings were 680–970 HV, whereas that of low-alloy steel was 174 HV. The wear resistance of the composite coatings increased as the Ti/Nb atomic ratio decreased. The composite coating had the highest average microhardness and the best wear resistance when Ti/Nb = 1:3. Its average microhardness was five times more than that of the low-alloy steel. In addition, the mass loss of the composite coating was 0.4 mg, which is only one-sixth that of the low-alloy steel (2.4 mg). The main reason for this was the in-situ formation of (Ti, Nb) (C, N) particles, which were evenly distributed in the composite coatings.

Effect of SHS Powder Processing on Structure Formation and Optical Transmittance of MgO-Y2O3 Composite Ceramic

Extending the transparency range of MgO-Y2O3 composite ceramic to wavelength less than 3 μm is highly desirable, as it broadens their potential applications in infrared (IR) optics. This study illustrates the effectiveness of deagglomerating a mixture of magnesium oxide and yttrium sesquioxide powders, derived from self-propagating high-temperature synthesis (SHS), in achieving this goal. The impact of powder deagglomeration on the microstructure and porosity defects of hot-pressed MgO-Y2O3 ceramic was analyzed using electron and IR microscopy. The results showed that the deagglomeration enhanced the homogeneity of the composite grain mixture, slowed down the grain growth, suppressed the formation of large grains, and significantly reduced the number of porosity microdefects in the material. The optical transmittance increased from 42% to 77% at a wavelength of 2 μm (for samples with a thickness of 1.2 mm) when deagglomerated powders were used, compared to non-deagglomerated ones.

Carburization Ability of Novel Solid Carburizing Method Using a Mixture of Iron, Graphite and Alumina Powders

Carburization Ability of Novel Solid Carburizing Method Using a Mixture of Iron, Graphite and Alumina Powders

Formulation, Evaluation &amp; Comparative Study of Effects of Super Disintegrants in Herbal Fast Dissolving Tablet of Nyctanthes Arbor Tristis.

The purpose of this research work was to formulate &amp; evaluate the herbal fast dissolving tablet of Nyctanthes Arbor Tristis. Taxonomically, the plant was authenticated by the Padmashri vikhe patil college of Arts, Science, &amp; Commerce in pravaranagar. Ref.No./PVPC/Bot./2023-24/235. The aimed is to treat inflammation associated with Sciatica. A two independent variables of superdisintegrants are used such as crosspovidone &amp; croscarmellose sodium. Using DOE software, 32 full factorial design was used to examine the combined impact of two formulation variables. TLC was performed to identify the beta sitosterol with RF value of 0.77. to determine the physicochemical interaction between the drug &amp; the excipients, FTIR study was done. FTIR study revealed that there is no interaction of the drug and excipient. In this investigation, the tablets were formulated and assessed via direct compression. The powder mixture were compressed into tablet using single punch tablet machine. All the formulations were evaluated for their characteristic such as weight variation, hardness, thickness, friability, disintegration time(DT), and dissolution rate. It was determined from all evaluation parameter that the F9 batch was the optimized batch. It was found that an optimized batch (F9) has good cumulative drug release in 20 minutes (88.87%), DT of 56 seconds, and hardness of 2.923kg/cm2. The comparative studies are done with the marketed formulation. With the commercial formulation, the optimized batchF9 satisfies all standard specification.

High-resolution, broad-spectral-range Raman measurement using a spatial heterodyne spectrometer with separate filters and multi-gratings

We propose a high-resolution, broad-spectral-range spatial heterodyne Raman spectrometer (SHRS) having separate filters and multi-gratings (SFMG). A prototype of the SFMG-SHRS is built using multi-gratings with four sub-gratings having groove densities of 320, 298, 276, and 254 gr/mm and separate filters with filter bands corresponding to the sub-gratings. We use the SFMG-SHRS to measure the Raman spectra of inorganic and organic compounds with various integration times, laser power, and transparent containers, compare measurements of microplastics with and without the separate filters, and measure mixtures of inorganic powders and organic solutions. The designed SFMG-SHRS makes high-resolution, broad-spectral-range Raman measurements with improved signal-to-noise ratios and visibility of weak Raman peaks even in the presence of fluorescence.

Optimal design and simulation investigation for high-density hydrogen storage tanks filled with rare earth-based (RE-Ca)(Ni-Co)5 optimized alloy

The slow kinetic rate due to strong thermal effect limits the practical application of metal hydride tanks in high-density hydrogen storage. In this work, we concentrate on a comprehensive experimental and numerical investigation of metal hydride beds with rare earth-based (RE-Ca)(Ni-Co)5 optimized alloy to explore faster reaction rates. Two different cylindrical tanks were manufactured to reflect de-/hydrogenation characteristics. A study on the temperature evolution in the loose powder bed was performed first, followed by five other different bed configurations: alternated powder layers with Al fiber layers, powder mixed with Al fibers, compacted discs (mixture of powder, resin and graphite), alternated compacts with Al fins and alternated Al foil-wrapped compacts with Al fins. Among them, the compacts provide good heat transfer capacity, with additional Al foils and fins for optimum thermal diffusion, reducing the reaction time by almost 50 %. Stress concentrations caused by powder accumulation can also be avoided thanks to the stable structure. Finally, the numerical model was adapted to simulate the de-/hydrogenation processes of the optimized bed and the experimental data matched well with the computational results, confirming the reliability of the model. It lays the foundation for the design and operation optimization of high-density hydrogen storage in the future.