Mixed Powders Research Articles

Study on the impact of water absorption processes on the application of wood waste in composite material production

The issue of recycling and reusing waste from the wood processing industry has garnered significant attention from researchers, as effective solutions could yield economic benefits while mitigating environmental impacts. This article focuses on the development of artificial wood using unsaturated polyester resin combined with waste materials from carpentry workshops, specifically investigating its water absorption properties. Research findings indicate that the water absorption coefficient of the samples increased with longer immersion times, higher organic filler content, and larger particle diameters. The calculated density reveals a broad spectrum of solid industrial boards that can be produced from these compositions, suggesting that consistent forming conditions enhance economic viability. Notably, optimal results were achieved with samples made from mixed wood powder without prior sorting, which contributes to reduced production costs, aligning with the study's objectives. Furthermore, the investigation highlighted that the water absorption coefficient escalates with increased soaking time, organic filler content, and particle size, indicating that in humid environments, it is advisable to limit both filler content and particle size to maintain performance. Overall, the studies confirm the feasibility of utilizing wood powder as a filler, with varying particle diameters imparting distinct characteristics to the final product. These findings underscore the potential for innovative approaches to wood waste management in the industry.

Efficiency of Vivianite from Water Purification Depending on Its Mixing with Superphosphate and Application Method

Vivianite precipitation is gaining attention in phosphorus (P) removal from water purification. It is an iron (Fe)- and P-rich compound that can be used as a slow-release P fertilizer. However, this slow release can constrain P supply to crops in the initial growing stages. This limitation can be overcome by mixing with soluble P fertilizers and with banding application. Thus, the objective of this study was to assess the fertilizer effect of vivianite and superphosphate mixtures and determine the most effective application method for vivianite and its mixture with superphosphate as a soluble fertilizer. A pot experiment was conducted by growing sunflowers in calcareous soil under controlled conditions involving two factors. The first factor was the combinations of vivianite and superphosphate: 100% Vivianite + 0% Superphosphate –T2–, 70% Vivianite + 30% Superphosphate –T3–, 30% Vivianite + 70% Superphosphate –T4–, 0% Vivianite + 100% Superphosphate –T5—at a single P rate of 50 mg P kg−1 and a non-fertilized control –T1–. The second factor was the application method: (i) mixing vivianite powder with the bulk soil and (ii) applying it in bands at three points around the plants. The dry matter (DM) yield in the roots and shoots of the sunflower when all P was applied as superphosphate was higher than when it was applied as vivianite. However, the combination of superphosphate and vivianite in different proportions (T3 and T4) led to a considerably higher DM yield compared to sole vivianite application (T2). The highest plant P uptake was observed in T5, while the lowest was in T1 and T2. The replacement values on a dry matter (PFRVDM) and P uptake (PFRVP Uptake) basis and the nutrient use efficiency of T3 and T4 were higher than that of T2. However, the PFRVDM and the PFRVP Uptake were in the same range as the proportion of the superphosphate added to the fertilizer mix. Thus, increased P use efficiency could be achieved with mixtures of vivianite and superphosphate. However, the contribution of vivianite to the fertilizer mix is difficult to access in a short growing cycle. Hence, further research is recommended on the residual effect of vivianite in such fertilizer mix on subsequent growing cycles.

Corrosion resistance and wear behavior of CoCrFeNiMn@Gr high entropy alloy-based composite coatings prepared by laser cladding

In this study, we utilize laser cladding to apply a CoCrFeNiMn HEA with 2 wt.% few-layer graphene (Gr) coating onto the surface of Q235B mild steel. Alcohol stirring method was used for HEA and Gr preparation of composite powder. Raman spectroscopy and energy dispersion spectroscope (EDS) indicate the successful mixing of HEA and Gr powders, with Gr adhering to the surface of the HEA powder in a lamellar structure. The X-ray diffraction (XRD), scanning electron microscope (SEM), EDS, and Electron backscatter diffraction (EBSD) analyses revealed that grain refinement and the formation of fine carbide-hard phases in the HEA/Gr coating improve microhardness and wear resistance. The average Schmidt factors of the coating decreased from 0.47 to 0.45 with the addition of Gr, indicating enhanced resistance to plastic deformation and anisotropy. Nanoindentation experiments demonstrated that the HEA/Gr coatings exhibit superior resistance to plastic deformation, effectively enhancing the coating’s durability against spalling under stress and wear conditions. The microhardness of the HEA/Gr coating increased by 99.25%, and the wear rate decreased by 86.31% compared to the HEA coating alone. The open circuit potential (OCP), linear polarization curve, Tafel curves, electrochemical impedance spectroscopy (EIS), and Mott-Schottky tests all indicated that the HEA/Gr coating possesses superior corrosion resistance. X-ray Photoelectron Spectroscopy (XPS) results suggest that the passivation film of the HEA/Gr coating, which contains more oxides and less hydroxide, is more protective and denser, thereby slowing the corrosion rate.

Design and optimization of stirrer and mixer design for the correct mixing of pharmaceutical powders through DEM

Mixing of granular materials is an important process for pharmaceutical industries. In this study, a quantifiable calculation method was suggested to determine the final mixing degree of the mixture. Based on that, the effect of the stirrer design, rotational speed, powder density, cohesivity, material ratios, and particle movement in the chamber guided through different designs of deflectors on the final mixing quality is examined. The results show that increasing the stirring speed, generates better mixing quality. However, introducing a varying rotational speed mode improves the mixing degree specially for binary mixtures with high relative densities. The improvement of the mixing with the number of contacting blades is observed. Finally, the introduction of a simple deflector drastically enhances the mixing quality and enables the feeding into the chamber, which is key for continuous operation with cohesive powders, making the process more stable and efficient by using more of the mixing volume.

Systematic analysis of mixing and segregation patterns of binary mixtures in fluidised beds for multi-functional processes

Fluidized beds are increasingly used in renewable energy and chemical production due to their versatility in handling different solids for multi-functional industrial applications. The diversity in size and density of solid particles impacts fluidization, influencing mixing and segregation behaviours critical for optimizing chemical processes and reactor design. This study investigates the expansion and segregation behaviours of mixed Geldart group powders in binary systems, simulating polydispersed beds with different materials and catalysts. By applying a modified Cheung equation and an adapted Gibilaro-Rowe model, the study analyzes segregation behaviours of Geldart Group A and B materials at varying mixing rates and gas flow velocities. Results show a good match between experimental data and model predictions. Using novel non-invasive X-ray imaging, the study provides real-time analysis of mixing and segregation at different fluidization regimes and temperatures. These findings aid in designing and optimizing advanced thermochemical conversion technologies, enhancing process efficiency and resilience.

Morphology and structural properties of Sb2(SxSe1-x)3 thin film absorbers for solar cells

Using the thermal evaporation method, thin crystalline films of Sb2(Sx Se1-x)3 are produced at the substrate temperature of 300℃. The mixed powders of the Sb2S3 and Sb2Se3 is used as a source material. The influence of the S/Se component ratio on the morphology and structural characteristics of Sb2(SxSe1-x)3 thin films is investigated. As demonstrated by the results of X-ray energy dispersive spectroscopy, the formed films of Sb2(SxSe1-x)3 have a components ratio close to the stoichiometry. Besides, Morphological and structural analyses reveal significant differences in the surface morphology of Sb2(SxSe1-x)3 thin film absorbers, indicating that the properties of the films vary as a function of the S/Se composition ratio.

Bioconversion of insect protein biomass into a fishmeal alternate for freshwater fish, Oreochromis mossambicus (Peters, 1852) diets

Abstract The demand for alternative fishmeal has increased significantly in recent years due to the expansion of the fishing industry. Therefore, insect proteins are becoming more popular as an alternative low-cost bio-source for fish than plant-based fish feeds. In the present study, a dietary mixture of insect protein powder derived from four Indian grasshopper species, namely Oxya hyla hyla, Atractomorpha crenulata, Oxya japonica japonica, and Phlaeoba infumata (insect meal, IM) was substituted for conventionally used fishmeal (FM) in the diet formulation for growing Mozambique tilapia, Oreochromis mossambicus (Peters, 1852) fingerlings. Three formulated diets with IM were prepared, with FM substituted at the rates of 25%, 50%, and 75%, respectively, with a control diet with no IM but only 20% FM. All dietary treatments were administered to tilapia fingerlings for 60 days under laboratory conditions. IM-incorporated diets outperform FM-incorporated diets in growth and digestibility due to their higher food conversion ratio for IM. In terms of growth and survivability in tilapia fingerlings, a 75% replacement of FM with IM demonstrated the most significant efficacy. According to the findings, mixed insect powder derived from four grasshopper species can be used as a partial replacement for FM in formulating the compound fish diet for tilapia fingerlings.

Sintering Behavior and Mechanical Properties of Ti–TiBw Composites Prepared with Pre‐alloyed Ti–TiBw Composite Powders

Prealloyed powders present a promising alternative to traditional ball milling processes in powder metallurgy, addressing challenges such as uneven powder mixing and incomplete reinforcement reactions. This study investigates the preparation of Ti–TiBw composites using spark plasma sintering (SPS) at temperatures ranging from 950 to 1050 °C, utilizing Ti–TiBw prealloyed composite powders. The effects of sintering temperature on the microstructure and mechanical properties of Ti–TiBw composites are studied, comparing prealloyed composite powders with ball‐milled premixed powders. As a result, the composites exhibit excellent strength and ductility, with an ultimate tensile strength of 676 MPa at 1000 °C and an elongation of 20.42% at 1050 °C. Comparatively, Ti–TiBw composites prepared from premixed powders achieve densification at 1050 °C, 50 °C higher than those prepared from prealloyed powders.

Influence of casting-warm pressing process on the thermal conductivity of micro–nano-Al2O3 substrate

Alumina substrates are increasingly used for high-power integrated circuits due to their high thermal conductivity, low thermal expansion coefficient, and excellent insulation properties. However, pores in the green tape from the tape casting process reduce the thermal conductivity and permittivity of the sintered ceramic substrate. Researchers have attempted to minimize ceramic porosity with chemical additives or by sintering pure alumina at temperatures above 1650 °C, but these methods often degrade thermal conductivity or quality of substrate evenness. This study proposes a low-cost casting-warm pressing process to densify pure alumina ceramic substrates using micro–nano-mixed alumina powders and sintering at relatively low temperatures. The results indicate that the relative density of the pure alumina ceramic substrate prepared at 1500 °C is 93%, a 4.4% improvement over the tape casting process. Additionally, the thermal conductivity of the alumina substrate from the casting-warm pressing process reaches 15.89 W/(m K), which is 1.4 times higher than that of the tape casting process. Microstructure analysis shows that the casting-warm pressing process with micro- and nano-multi-scale mixed alumina powders forms a novel thermal conduction enhancement mechanism. Large particles in the green tape overlap, while small particles fill the spaces between the large particles. The connected micrometer-sized particle skeletons form high thermal conduction net channels in the substrate, improving the thermal conductivity for heat transfer.

Determination of steady-state for continuous powder mixing: Analysis of mixture properties and signal processing

Continuous powder mixing offers many advantages over batch processes, but its industrial implementation requires control of transient phases due to startup or variations in operating conditions. Detecting the steady-state by observing the mixture properties, obtained through in-line analysis of the mixture composition, is challenging due to the significant fluctuations in these properties. However, there is no quantitative method for identifying the steady-state for continuous powder mixing. We therefore propose in this work a methodology for steady-state detection by comparing several methods of mixture property analysis and signal processing. We show that conventional methods of mixture property analysis cannot reliably and accurately detect steady-state. We conclude that the best methodology is to perform signal processing on the content of the key component in the mixture. To do this, the signal of the content of the key component is first smoothed by the Savitzky-Golay filter. Then, the standard deviation of the filtered signal is compared with a tuning parameter to detect the beginning of steady-state. This method could be used to determine the mixing conditions leading to the smallest startup time, hence avoiding costly waste.

The association between brominated flame retardants exposure with Parkinson's disease in US adults: a cross-sectional study of the National Health and Nutrition Examination Survey 2009-2016.

Increasing evidence suggests that environmental factors play a crucial role in the pathogenesis of Parkinson's disease (PD). Humans are simultaneously exposed to multiple brominated flame retardants (BFRs) in the environment. However, the relationship between BFRs and PD remains unclear. This study was designed to investigate the overall association between BFRs and PD in a nationally representative US population and to further identify significant chemicals. This study used data from 7,161 NHANES participants from 2009 through 2016. The serum BFRs registry included PBDE-28, PBDE-47, PBDE-85, PBDE-99, PBDE-100, PBDE-153, PBDE-154, PBDE-183, PBDE-209, and PBB-153. A survey-weighted generalized logistic regression model with restricted cubic splines (RCS) was used to evaluate the association between single BFRs exposure and periodontitis. Meanwhile, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were used to evaluate the overall association of mixed frankincense powder with periodontitis and to identify significant chemicals. Sensitivity analysis was performed to evaluate the robustness of the results. Among the 7,161 participants, 65 had PD. PD patients were older (mean age 57.79 vs. 46.57 years) and had a higher proportion of females (70.86%) compared to non-PD participants. Serum levels of PBB-153 were significantly higher in those with PD. Logistic regression analyses revealed a non-linear, inverted U-shaped relationship between serum PBB-153 and PD risk. The risk of PD increased with higher PBB-153 levels up to the 3rd quartile (Q3), beyond which the risk declined (Q3 vs. Q1: OR = 4.98, 95% CI = 1.79-13.86; Q4 vs. Q1: OR = 3.23, 95% CI = 1.03-10.08). PBB-153 (43.40%), PBDE-153 (24.75%), and PBDE-85 (19.51%) contributed most to the weighted quantile sum index associated with PD risk. Bayesian kernel machine regression confirmed the inverted U-shaped dose-response pattern for PBB-153 and the overall BFR mixture. Restricted cubic spline analyses corroborated the non-linear relationship between PBB-153 and PD, which was more pronounced among women and those aged 37-58 years. Sensitivity analyses substantiated these findings. This nationally representative cross-sectional study revealed a novel non-linear, inverted U-shaped relationship between serum levels of the brominated flame retardant PBB-153 and Parkinson's disease risk in U.S. adults. The risk increased with higher PBB-153 exposure up to a point, beyond which it declined. This complex dose-response pattern highlights the importance of considering potential hormetic mechanisms and effect modifiers when evaluating environmental exposures and neurodegenerative diseases. Further research is warranted to elucidate the underlying biological pathways and inform risk mitigation strategies.

Integral LOCA experiments to study FFRD behavior of high burnup nuclear fuels

This paper introduces the Integral Loss Of Coolant (LOCA) facility (i-LOCA) established at Seoul National University. The facility was designed to investigate the integral fuel behavior of Light Water Reactors during LOCA, encompassing aspects such as cladding oxidation, ballooning and burst, reflood quenching, secondary hydriding, and fuel pellet dispersal. Integral LOCA experiments were carried out using three types of surrogate ZrO2 pellets, representing various segment burnups: cylindrical pellets with no fuel fragmentation (<55 GWd/MTU), mixed fragments of different sizes simulating ∼68 GWd/MTU (D = 0.3, 0.5, 1.0, 2.0, 3.0, and 5.0 mm with the same mass fraction), and small single powdered fragments simulating ultra-high burnup fuel (D = 0.5 mm, ∼94 GWd/MTU). Zr-Nb-Sn, Zr-1.1Nb, and Cr-coated (15 μm, Arc Ion Plating) Zr-1.1Nb ATF cladding were employed, with rod internal pressures ranging from 1 MPa to 7 MPa. The burst size and hoop strain exhibited significant variations depending on the type of surrogate pellets used, with larger burst sizes and hoop strains observed for smaller average diameters of surrogate pellets due to the effect of azimuthal and axial temperature distribution. Fuel dispersal was influenced by rod internal pressure, burst size, and the size of pellet fragments. Only pellet fragments smaller than the burst hole width underwent dispersal upon fuel burst, while larger fragments blocked the dispersal of smaller fragments. The rapidly escalating average dispersal fraction of single powder compared to mixed powder indicated a threshold burnup for fuel dispersal between 69–94 GWd/MTU. Cladding inner oxidation length was influenced by burst hole size and remaining fuel pellets. The results of inner oxidation confirmed the validity of the U.S. NRC’s assumption regarding the length of inner wall oxidation. The tested 15 μm Cr-coated cladding tubes, produced using the arc ion plating method, exhibited no significant differences in burst geometry, fuel dispersal, inner oxidation, and secondary hydriding when compared to the uncoated reference cladding.

ВЛИЯНИЕ ПРОДОЛЖИТЕЛЬНОСТИ МЕХАНИЧЕСКОЙ АКТИВАЦИИ МЕТАЛЛИЧЕСКИХ ПОРОШКОВ ПРИ ИХ СМЕШИВАНИИ НА ПРОЧНОСТЬ ПЛАЗМЕННОГО ПОКРЫТИЯ

The article considers the effect of the duration of mixing the components of the FeCoCrAlTiCuMo coating in a special mixer-activator on the strength of the resulting coating. Indirect confirmation of the effect of mechanical activation during mixing on the formation of the plasma coating was obtained and a rational mixing time was determined. Based on the data obtained, it is possible to judge the possibility of creating a HES coating by mixing the components in an inert atmosphere, which allows increasing the strength of the coating by more than 2 times, in comparison with mixing powders by the traditional method in an air atmosphere.

Fabrication of Low-Cost Porous Carbon Polypropylene Composite Sheets with High Photothermal Conversion Performance for Solar Steam Generation.

The development of absorber materials with strong light absorption properties and low-cost fabrication processes is highly significant for the application of photothermal conversion technology. In this work, a mixed powder consisting of NaCl, polypropylene (PP), and scale-like carbon flakes was ultrasonically pressed into sheets, and the NaCl was then removed by salt dissolution to obtain porous carbon polypropylene composite sheets (P-CPCS). This process is simple, green, and suitable for the low-cost, large-area fabrication of P-CPCS. P-CPCS has a well-distributed porous structure containing internal and external connected water paths. Under the dual effects of the carbon flakes and porous structure, P-CPCS shows excellent photothermal conversion performance in a broad wavelength range. P-CPCS-40 achieves a high temperature of 128 °C and a rapid heating rate of 12.4 °C/s under laser irradiation (808 nm wavelength, 1.2 W/cm2 power). When utilized for solar steam generation under 1 sun irradiation, P-CPCS-40 achieves 98.2% evaporation efficiency and a 1.81 kg m-2 h-1 evaporation rate. This performance means that P-CPCS-40 outperforms most other previously reported absorbers in terms of evaporation efficiency. The combination of carbon flakes, which provide a photothermal effect, and a porous polymer structure, which provides light-capturing properties, opens up a new strategy for desalination, sewage treatment, and other related fields.

Development of a high-fidelity digital twin using the discrete element method for a continuous direct compression process. Part 2. Validation of calibration workflow

This paper is the second in a series of two that describes the application of discrete element method (DEM) and reduced order modeling to predict the effect of disturbances in the concentration of drug substance at the inlet of a continuous powder mixer on the concentration of the drug substance at the outlet of the mixer. In the companion publication, small-scale material characterization tests, a careful DEM parameter calibration and DEM simulations of the manufacturing process were used to develop a reliable RTD models. In the current work, the same calibration workflow was employed to evaluate the predictive ability of the resulting reduced-order model for an extended design space. DEM simulations were extrapolated using a relay race method and the cumulative RTD was accurately parameterized using the n-CSTR model. By performing experiments and simulations, a calibrated DEM model predicted the response of a continuous powder mixer to step changes in the inlet concentration of an API. Thus, carefully calibrated DEM models was used to guide and reduce experimental work and to establish an adequate control strategy. In addition, a further reduction in the computational effort was obtained by using the relay race method to extrapolate results. The predicted RTD curves were then parameterized to develop reduced order models and used to simulate the process in a matter of seconds. Overall, a control strategy evaluation tool based on high-fidelity DEM simulations was developed using material-sparing small-scale characterization tests.

Joining SiC ceramics with CaO-Al2O3-SiO2 mixed powder/glass based on induction heating

CaO-Al2O3-SiO2 mixed powder and glass were used as the joining materials to join SiC ceramics by induction heating in a joining temperature range of 1400–1600 °C under pressureless condition with heating and cooling rates of 100 °C/min. The joint prepared with CaO-Al2O3-SiO2 mixed oxide powder as joining material has the highest shear strength of 60.09 ± 6.22 MPa at joining temperature of 1500 °C, which contains triclinic CaAl2Si2O8 crystalline phase generated by chemical reaction in the holding process. In contrast, the joint produced with CaO-Al2O3-SiO2 glass powder at 1500 °C also has the highest shear strength of 75.76 ± 2.34 MPa, which contains hexagonal CaAl2Si2O8 and quartz generated through crystallization in the holding process due to rapid cooling rate of induction heating. In this study, the feature of mixed powder and glass joining by the induction heating technology was discussed to provide an effective and economic method for ceramic joining.

Investigation on melt growth (Mg, Co, Ni, Cu, Zn)O oxide ceramics prepared by laser directed energy deposition

High-entropy oxides (HEOs) have attracted extensive research interest due to their unique structural features, customizable elemental compositions, and tunable functional properties. Nevertheless, the complexity, low efficiency, and high cost of the existing HEO synthesis methods place limitations on them. In this study, Laser directed energy deposition (LDED) was employed to synthesize (Mg, Co, Ni, Cu, Zn)O oxides. Additionally, the novelty of applying the LDED process to multicationic systems was emphasized. The comparison between specimens fabricated from mixed powder via LDED(MP) and those fabricated from pre-sintered powder via LDED(SP) encompasses macroscopic morphology, microstructure, and performance. The results showed that SP significantly enhanced the density from 86.44% to 96.70% compared to MP. The macro-segregation of Cu and Cu2O in the phase composition was observed in MP and SP. High-temperature pre-sintering promoted the solid solution formation of Co and Ni during LDED, leading to more severe micro-segregation of Co and Ni. When employed as anodes in lithium-ion batteries, MP and SP have outstanding long-term cycle stability, according to electrochemical performance studies. At a current density of 100 mAg-1, these specimens maintained a capacity retention rate of 100% even after 200 cycles. The initial discharge capacities of MP and SP were respectively 477.73 mAh g-1 and 373.86 mAh g-1. This study is expected to present a novel approach for the rapid synthesis of (Mg, Co, Ni, Cu, Zn)O oxide ceramics.

Theoretical modeling of feedstock-laser energy interaction in directed energy deposition with simultaneous wire and powder feeding

The Laser-based Directed Energy Deposition (L-DED) process is widely employed for the fabrication of numerous metallic parts. It also stands out as a crucial additive manufacturing (AM) technique for creating metal matrix composites (MMCs) reinforced with ceramic particles. The simultaneous deposition of wire and powder feedstocks into the created melt pools on the substrate surface proves advantageous in overcoming the limitations associated with mixed powders in powder deposition alone. The strategy of coaxial wire and powder deposition (CWP-DED) allows for more efficient construction of MMCs with complex geometries and desirable properties. Nevertheless, CWP-DED is a complex multi-phase deposition process that involves highly dynamic interactions among laser beams, wire, and powder particles, influencing laser energy distribution and absorption during the process. This work aims to develop a theoretical model to advance the fundamental understanding of the absorbed and lost laser beam energy by the fed wire and powders in CWP-DED before entering the melt pool. Laser energy absorption coefficients can be calculated based on the Step Wise Heating method to determine the final temperature of the powder particles and wire before entering the melt pool. The experimental validation of the proposed model requires a power meter that fits the CWP-DED system with six inclined laser beams, which is not commercially available so far, to measure the actual output power with and without wire and powder feeding. Consequently, this work presents a detailed explanation of the experimental procedure desired to measure the absorption coefficients of the wire and powder feedstocks and how to validate the proposed model as a future research endeavor. This model plays a vital role in predicting and understanding the amount of heat transferred into the melt pool, which lays a foundation for understanding the complicated melt pool thermodynamics that directly govern the microscopic characteristics and macroscopic properties of the as-built parts.

Developing a hybrid-built pre-hardened alloy steel for injection moulding tools using the laser powder bed fusion process

Hybrid additive-subtractive manufacturing has been adopted as a cost-effective alternative for manufacturing plastic injection moulding tools with conformal-cooled inserts created by fusing powder and wrought material. This article reports the development of a hybrid power-wrought pre-hardened alloy steel to supplement the current material choice for fabricating injection mould inserts using this advanced manufacturing strategy. In this study, MS1 (maraging 300) steel powder was additively deposited onto pre-machined wrought Nimax steel to form a hybrid alloy material. The mechanical and microstructural properties of the fusion-bonded interface were examined. Microstructural observation revealed a 280 μm thick interfacial region consisting of a homogenous mixing of powder and substrate materials. As a result of solid solution strengthening within the region, tensile tests established robust powder-substrate bonding with tensile ruptures occurring well away from the interface. The as-built hybrid-alloy steel possessed excellent mechanical properties, with 1200 MPa in ultimate tensile strength, 12.4 % in elongation at fracture and 39 HRC (Nimax)/42 HRC (MS1) in hardness. The overall results suggested that hybrid MS1-wrought Nimax steel is a suitable pre-hardened material for manufacturing durable and high-performance injection mould inserts as part of a cost-effective hybrid additive-subtractive manufacturing strategy.

Simulation of the Die and Punch Behavior During the Compaction Process of Alumina-Based Matrix Composite Using Finite Element Analysis

Background: Compaction in the powder metallurgy process typically involves using a die and punch, applying high pressure to mixed powder to achieve product quality, such as geometry, density, and porosity. This step is critical in the powder metallurgy process. Objective: This study aims to systematically design and manufacture a die and punch for compacting an Alumina-based matrix composite. Specimens were selected according to ASTM C 1421-10 guidelines, and the die and punch were constructed using AISI D3 tool steel alloy. Methods: To ensure satisfactory compaction, the design underwent virtual testing using Finite Element Analysis (FEA) with compaction loads ranging from 2.5 to 20 tons in 2.5-ton increments. The simulation results were validated through experimental testing. Results: The die parts were analyzed for three-dimensional stress and deformation during compaction. Maximum stress distribution was observed in the Alumina powder, followed by the punch, plate, and die. Additionally, compaction behavior and density tests confirmed that a compaction pressure of 548 MPa or more results in high relative density in the Alumina-based matrix composite powder during the compaction process. Conclusion: Both simulation and experimental results indicate that a compaction pressure of 548 MPa or more is necessary to achieve satisfactory compaction of the Alumina-based matrix composite. These findings offer practical implications for optimizing the powder metallurgy compaction process and reducing costs.