Journal of Powder Materials

[English]
Fabrication and Pore Characteristics of Metal Powder Filters with a Cross-Sealed Honeycomb Shape Using Material Extrusion Additive Manufacturing: Minji Kim, Min-Jeong Lee, Su-Jin Yun, Poong-Yeon Kim, Hyeon Ju Kim, Juyong Kim, Jung Woo Lee, Jung-Yeul Yun; J Powder Mater. 2025;32(4):299-308. Published online August 29, 2025; DOI: https://doi.org/10.4150/jpm.2025.00234

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Abstract PDF: The development of high-performance metal filters is essential for maintaining ultra-clean environments in semiconductor manufacturing. In this study, cross-sealed honeycomb filters were fabricated using STS316L powder via material extrusion additive manufacturing (MEAM) for semiconductor gas filtration. The effects of filter geometry (4 or 9 channels) and sintering temperature (850°C, 950°C, or 1,050°C) on performance were examined. First, 4-channel and 9-channel filters sintered at the same temperature (950°C) exhibited similar porosities of 50.08% and 50.57%, but the 9-channel filter showed a higher pressure-drop (0.26 bar) and better filtration-efficiency (3.55 LRV) than the 4-channel filter (0.19 bar and 3.25 LRV, respectively). Second, for filters with the same geometry (4-channel) increasing the sintering temperature reduced porosity from 64.52% to 40.33%, while the pressure-drop increased from 0.13 bar to 0.22 bar and filtration-efficiency improved from 2.53 LRV to 3.51 LRV. These findings demonstrate that filter geometry and sintering temperature are key factors governing the trade-off between air permeability, pressure-drop, and filtration efficiency. This work provides insights and data for optimizing MEAM-based high-performance metal powder filter design.

[English]
Cost-effective Fabrication of Near β-Ti Alloy via L-PBF: Process Optimization of In-situ Alloying Ti-3Fe: Sehun Kim, Ukju Gim, Taehu Kang, Jongik Lee, Sanghee Jeong, Jimin Han, Bin Lee; J Powder Mater. 2025;32(4):288-298. Published online August 29, 2025; DOI: https://doi.org/10.4150/jpm.2025.00213

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Abstract PDF: This study presents a cost-effective approach to fabricating near β-Ti alloys via in-situ alloying during laser powder bed fusion (L-PBF). A blend of non-spherical pure Ti, 3 wt.% Fe, and 0.1 wt.% SiO2 nanoparticles was used to induce β-phase stabilization and improve flowability. Twenty-five process conditions were evaluated across a volumetric energy density range of 31.75-214.30 J/mm3, achieving a maximum relative density of 99.21% at 89.29 J/mm3. X-ray diffraction analysis revealed that the β-Ti phase was partially retained at room temperature, accompanied by lattice contraction in the α’-Ti structure, indicating successful Fe incorporation. Elemental mapping confirmed that the Fe distribution was homogeneous, without significant segregation. Compared to pure Ti, the Ti-3Fe sample exhibited a 49.2% increase in Vickers hardness and notable improvements in yield and ultimate tensile strengths. These results demonstrate the feasibility of in-situ alloying with low-cost elemental powders to produce high-performance near β-Ti alloys using L-PBF.

[Korean]
The Recycling Process and Powderization Technology of Stellite 6 Scrap: A Thermodynamic and Heat Transfer Analysis: YongKwan Lee, Hyun-chul Kim, Myungsuk Kim, Soong Ju Oh, Kyoungtae Park, JaeJin Sim; J Powder Mater. 2025;32(4):330-343. Published online August 29, 2025; DOI: https://doi.org/10.4150/jpm.2025.00136

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Abstract PDF: Co-Cr alloys are widely used in cutting tools and turbine components due to their high strength and resistance against wear and corrosion. However, scrap generated during hardfacing is often discarded due to impurities and oxidation, and research on its recycling remains limited. This study aimed to optimize the recycling process of Stellite 6 scrap to reduce waste and minimize costs while maintaining material quality. Melting, casting, and powdering processes were designed using HSC Chemistry, FactSage, and COMSOL Multiphysics, with optimization of key parameters such as the crucible material and temperature control. The recycled alloy and powder were analyzed using X-ray fluorescence analysis, inductively coupled plasma optical emission spectroscopy, and X-ray diffractometry, showing mechanical and chemical properties comparable to commercial Stellite 6. The Co and Cr contents were maintained, with a slight increase in Fe. These findings demonstrate the potential for producing high-quality recycled Stellite 6 materials, contributing to the sustainable utilization of metal resources in high-performance applications.

[English]
Enhanced Compressive Strength of Fired Iron Ore Pellets: Effects of Blending Fine and Coarse Particle Concentrates: Ngo Quoc Dung, Tran Xuan Hai, Nguyen Minh Thuyet, Nguyen Quang Tung, Arvind Barsiwal, Nguyen Hoang Viet; J Powder Mater. 2025;32(4):315-329. Published online August 29, 2025; DOI: https://doi.org/10.4150/jpm.2025.00129

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Abstract PDF: This study investigated the effects of oxidative firing parameters and raw material characteristics on the pelletization of Australian and Minh Son (Vietnam) iron ore concentrates. The influence of firing temperature (1050°C–1150°C) and holding time (15–120 min) on pellet compressive strength was examined, focusing on microstructural changes during consolidation. Green pellets were prepared using controlled particle size distributions and bentonite as a binder. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed that grain boundary diffusion, liquid phase formation, and densification significantly improved mechanical strength. X-ray diffraction confirmed the complete oxidation of magnetite to hematite at elevated temperatures, a critical transformation for metallurgical performance. Optimal firing conditions for both single and blended ore compositions yielded compressive strengths above 250 kgf/pellet, satisfying the requirements for blast furnace applications. These results provide valuable guidance for improving pellet production, promoting the efficient utilization of diverse ore types, and enhancing the overall performance of ironmaking operations.

[English]
Laser Processing of an Al_0.1CoCrFeNi High Entropy Alloy + Cu Composite Powders via Laser Powder Bed Fusion: Kwangtae Son, Ji-Woon Lee, Soon-Jik Hong, Somayeh Pasebani; J Powder Mater. 2025;32(4):277-287. Published online August 29, 2025; DOI: https://doi.org/10.4150/jpm.2025.00101

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Abstract PDF: This study examined process–structure relationships in laser powder bed fusion of Al₀.₁CoCrFeNi + Cu composites, focusing on densification, elemental distribution, and solidification cracking. Mechanically mixed Al₀.₁CoCrFeNi and Cu powders were processed across a range of laser powers (100–250 W) and scan speeds (200–800 mm/s). Increased volumetric energy density (VED) improved densification, with a plateau near 200 J/mm³ yielding ~96% relative density; however, this value was still below application-grade thresholds. At low VED, insufficient thermal input and short melt pool residence times promoted Cu segregation, while higher VED facilitated improved elemental mixing. Elemental mapping showed partial co-segregation of Ni with Cu at low energies. Solidification cracks were observed across all processing conditions. In high VED regimes, cracking exhibited a minimal correlation with segregation behavior and was primarily attributed to steep thermal gradients, solidification shrinkage, and residual stress accumulation. In contrast, at low VED, pronounced Cu segregation appeared to exacerbate cracking through localized thermal and mechanical mismatch.

[English]
The Effect of Aluminum Powder Size on the Structure and Mechanical Properties of Foam: Seunghyeok Choi, Sungjin Kim, Tae-Young Ahn, Yu-Song Choi, Jae-Gil Jung, Seung Bae Son, Seok-Jae Lee; J Powder Mater. 2025;32(3):232-243. Published online June 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00157

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Abstract PDF: In this study, we analyzed the structural and mechanical properties of aluminum foams fabricated using aluminum powders of varying sizes and mixtures. The effects of sintering and pore structure at each size on the integrity and mechanical properties of the foams were investigated. Structural characteristics were examined using scanning electron microscopy and micro–computed tomography, while mechanical properties were evaluated through compression testing. The experimental results demonstrated that smaller powder sizes improved foam integrity, reduced porosity and pore size, and resulted in thinner cell walls. In combination, these effects increased compressive strength as the powder size decreased. The findings of this study contribute to the understanding and improvement of the mechanical properties of aluminum foams and highlight their potential for use in a wide range of applications.

[Korean]
Development of Aluminum Alloys for Additive Manufacturing Using Machine Learning: Sungbin An, Juyeon Han, Seoyeon Jeon, Dowon Kim, Jae Bok Seol, Hyunjoo Choi; J Powder Mater. 2025;32(3):202-211. Published online June 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00150

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Abstract PDF: The present study introduces a machine learning approach for designing new aluminum alloys tailored for directed energy deposition additive manufacturing, achieving an optimal balance between hardness and conductivity. Utilizing a comprehensive database of powder compositions, process parameters, and material properties, predictive models—including an artificial neural network and a gradient boosting regression model, were developed. Additionally, a variational autoencoder was employed to model input data distributions and generate novel process data for aluminum-based powders. The similarity between the generated data and the experimental data was evaluated using K-nearest neighbor classification and t-distributed stochastic neighbor embedding, with accuracy and the F1-score as metrics. The results demonstrated a close alignment, with nearly 90% accuracy, in numerical metrics and data distribution patterns. This work highlights the potential of machine learning to extend beyond multi-property prediction, enabling the generation of innovative process data for material design.

[English]
Self-Assembled Monolayers in Area-Selective Atomic Layer Deposition and Their Challenges: Si Eun Jung, Ji Woong Shin, Ye Jin Han, Byung Joon Choi; J Powder Mater. 2025;32(3):179-190. Published online June 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00094

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Abstract PDF: Area-selective atomic layer deposition (AS-ALD) is a bottom-up process that selectively deposits thin films onto specific areas of a wafer surface. The surface reactions of AS-ALD are controlled by blocking the adsorption of precursors using inhibitors such as self-assembled monolayers (SAMs) or small molecule inhibitors. To increase selectivity during the AS-ALD process, the design of both the inhibitor and the precursor is crucial. Both inhibitors and precursors vary in reactivity and size, and surface reactions are blocked through interactions between precursor molecules and surface functional groups. However, challenges in the conventional SAM-based AS-ALD method include thermal instability and potential damage to substrates during the removal of residual SAMs after the process. To address these issues, recent studies have proposed alternative inhibitors and process design strategies.

[Korean]
Effect of Support Structure on Residual Stress Distribution in Ti-6Al-4V Alloy Fabricated by Laser Powder Bed Fusion: Seungyeon Lee, Haeum Park, Min Jae Baek, Dong Jun Lee, Jae Wung Bae, Ji-Hun Yu, Jeong Min Park; J Powder Mater. 2025;32(3):244-253. Published online June 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00087

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Abstract PDF: Ti-6Al-4V alloy is widely utilized in aerospace and medical sectors due to its high specific strength, corrosion resistance, and biocompatibility. However, its low machinability makes it difficult to manufacture complex-shaped products. Advancements in additive manufacturing have focused on producing high-performance, complex components using the laser powder bed fusion (LPBF) process, which is a specialized technique for customized geometries. The LPBF process exposes materials to extreme thermal conditions and rapid cooling rates, leading to residual stresses within the parts. These stresses are intensified by variations in the thermal history across regions of the component. These variations result in differences in microstructure and mechanical properties, causing distortion. Although support structure design has been researched to minimize residual stress, few studies have conducted quantitative analyses of stress variations due to different support designs. This study investigated changes in the residual stress and mechanical properties of Ti-6Al-4V alloy fabricated using LPBF, focusing on support structure design.

[Korean]
Fabrication and Alloying Behavior of Ultra-Lightweight AlTiCrVMg High-Entropy Alloy via Al-Mg Mutual Solubility and Sintering Control: Eunhyo Song, Hansung Lee, Byungmin Ahn; J Powder Mater. 2025;32(3):254-261. Published online June 12, 2025; DOI: https://doi.org/10.4150/jpm.2025.00059

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Abstract PDF: High-entropy alloys (HEAs) incorporating low-melting-point elements (Mg and Al) and high-melting-point elements (Ti, Cr, and V) were fabricated via mechanical alloying and spark plasma sintering. Sintering temperatures were varied to investigate phase behavior and microstructural evolution. X-ray diffraction was used to identify phase structures, scanning electron microscopy to analyze microstructures, X-ray fluorescence to determine elemental composition, and a gas pycnometer to measure density. Micro-Vickers hardness testing was conducted to evaluate mechanical properties. Mechanical-alloyed HEAs exhibited a body-centered cubic (BCC) phase and lamellar structures with element-enriched regions. Sintering introduced additional BCC and Laves phases, while higher temperatures promoted Mg liquid-phase sintering, increasing density and hardness. This study highlights the effects of sintering on HEAs containing elements with differing melting points to optimize their properties.

[Korean]
Effect of Building Orientation on Tensile Properties of Hastelloy X alloy Manufactured by Laser Powder Bed Fusion: Seong-June Youn, GooWon Noh, Seok Su Sohn, Young-Sang Na, Young-Kyun Kim; J Powder Mater. 2025;32(2):131-137. Published online April 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00080

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Abstract PDF: In this study, the effect of build orientation on the mechanical properties of Hastelloy X fabricated by laser powder bed fusion (LPBF) process was investigated. Initial microstructural analysis revealed an equiaxed grain structure with random crystallographic orientation and annealing twins. Intragranular precipitates identified as Cr-rich M23C6 and Mo-rich M6C carbides were observed, along with a dense dislocation network and localized dislocation accumulation around the carbides. Mechanical testing showed negligible variation in yield strength with respect to build orientation; however, both ultimate tensile strength and elongation exhibited a clear increasing trend with higher build angles. Notably, the specimen built at 90° exhibited approximately 22% higher tensile strength and more than twice the elongation compared to the 0° specimen.

[English]
Ultra-Low-Temperature (4.2 K) Tensile Properties and Deformation Mechanism of Stainless Steel 304L Manufactured by Laser Powder Bed Fusion: Seung-Min Jeon, Young-Sang Na, Young-Kyun Kim; J Powder Mater. 2025;32(2):95-103. Published online April 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00066

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1 Citations

Abstract PDF

This study investigated the ultra-low-temperature (4.2 K) tensile properties and deformation mechanisms of stainless steel 304L manufactured via laser powder bed fusion (LPBF). The tensile properties of LPBF 304L were compared to those of conventional 304L to assess its suitability for cryogenic applications. The results revealed that LPBF 304L exhibited a significantly higher yield strength but lower ultimate tensile strength and elongation than conventional 304L at 4.2 K. The temperature dependence of the yield strength also favored LPBF 304L. Microstructural analysis demonstrated that LPBF 304L features a high density of dislocation cells and nano-inclusions, contributing to its greater strength. Furthermore, strain-induced martensitic transformation was observed as a key deformation mechanism at cryogenic temperatures, where austenite transformed into both hexagonal-closed packed (HCP) and body-centered cubic (BCC) martensite. Notably, BCC martensite nucleation occurred within a single HCP band. These findings provide critical insights into the mechanical behavior of LPBF 304L at cryogenic temperatures and its potential for applications in extreme environments.

Citations

Citations to this article as recorded by

Understanding the unique appearance behavior of shear bands during tensile deformation of α-brass at 4.2 K
Seon-Keun Oh, Sang-Hun Shim, Young-Kyun Kim, Young-Sang Na
Materials Science and Engineering: A.2025; 945: 148989. CrossRef

[Korean]
Effect of Cellulose Fiber Density Variation on Energy Harvesting Performance in a Hydrovoltaic Generator: Seung-Hwan Lee, So Hyun Baek, Hyun-Woo Lee, Yongbum Kwon, Kanghyuk Lee, Kee-Ryung Park, Yoseb Song, Bum Sung Kim, Ji Young Park, Yong-Ho Choa, Da-Woon Jeong; J Powder Mater. 2025;32(2):113-121. Published online April 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00052

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Abstract PDF: Energy harvesting has become a crucial technology for sustainable energy solutions; in particular, the utilization of ambient water movement in hydrovoltaic generators has emerged as a promising approach. However, optimizing performance requires an understanding of structural factors affecting energy harvesting, particularly capillary effects. This study aimed to improve hydrovoltaic generator performance by adjusting internal fiber density, which influences water transport and ion mobility. Using cold isostatic pressing, cellulose acetate (CA) loading in a urethane mold was varied to optimize internal density. As CA loading increased, the fiber arrangement became denser, narrowing capillary pathways and reducing proton mobility. While open-circuit voltage (VOC) remained stable, short-circuit current (ISC) decreased with higher CA mass. The sample with a loading of 0.3 g exhibited the highest energy harvesting efficiency, achieving ISC = 107.2 μA, VOC = 0.15 V, and power (P) = 16.7 μW. This study provides insights into methods of improving hydrovoltaic generator efficiency through internal structural modifications.

[English]
Stretch-Flangeability of Laser Powder Bed Fusion-Processed 316L Stainless Steel: Rae Eon Kim, Yeon Taek Choi, Sang Guk Jeong, Do Won Lee, Hyoung Seop Kim; J Powder Mater. 2025;32(2):87-94. Published online April 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00017

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Abstract PDF Supplementary Material: Metal additive manufacturing (AM) facilitates the production of complex geometries with enhanced functionality. Among various AM techniques, laser powder bed fusion (LPBF) is distinguished by its precision and exceptional mechanical properties achieved via laser fusion deposition. Recent advancements in AM have focused on combining LPBF with post-processing methods such as cold rolling, high-pressure torsion, and forming processes. Therefore, understanding the forming behavior of LPBF-processed materials is essential for industrial adoption. This study investigates the stretch-flangeability of LPBF-fabricated 316L stainless steel, emphasizing its anisotropic microstructure and mechanical properties. Hole expansion tests were employed to assess stretch-flangeability in comparison to wrought 316L stainless steel. The results demonstrate that LPBF-processed samples exhibit significant anisotropic behavior, demonstrating the influence of microstructural evolution on formability. These findings contribute valuable insights into optimizing LPBF materials for industrial forming applications.

[Korean]
Friction Stir Spot Welding Characteristics of Dissimilar Materials of Aluminum-Based Damping Composites and Steel Plates: Si-Seon Park, Young-Keun Jeong; J Powder Mater. 2025;32(1):43-49. Published online February 28, 2025; DOI: https://doi.org/10.4150/jpm.2025.00010

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Abstract PDF: Friction Stir Spot Welding (FSSW) is a solid-state welding technology that is rapidly growing in the automotive industry. Achieving superior welding characteristics requires the proper selection of tool geometry and process conditions. In this study, FSSW was performed on dissimilar materials comprising AA5052-HO/hot-melt aluminum alloy sheets and Steel Plate Cold Rolled for Deep Drawing Use(SPCUD) steel sheets. The effects of tool geometry, plate arrangement, and tool plunge depth on the welding process were investigated. At the joint interface between the aluminum alloy and the steel sheet, new intermetallic compounds (IMCs) were observed. As the plunge depth increased, thicker and more continuous IMC layers were formed. However, excessive plunge depth led to discontinuous layers and cracking defects. An analysis of the IMCs revealed a correlation between the IMC thickness and the shear tensile load. Furthermore, compared to the conventional Al-Top arrangement, the St-Top arrangement exhibited reduced deformation and superior shear tensile load values. These findings indicate that plate arrangement significantly influences the mechanical properties of the joint.

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