Skip Navigation
Skip to contents

Journal of Powder Materials : Journal of Powder Materials

OPEN ACCESS
SEARCH
Search

Search

Page Path
HOME > Search
285 "Co"
Filter
Filter
Article category
Keywords
Publication year
Authors
Funded articles
Research Articles
Article image
[English]
Preparation of Flake-shape Cobalt Powders by High-Energy Ball Milling for rSOC Current Collectors
Poong-Yeon Kim, Min-Jeong Lee, Hyeon Ju Kim, Su-Jin Yun, Si Young Chang, Jung-Yeul Yun
J Powder Mater. 2025;32(5):383-389.   Published online October 31, 2025
DOI: https://doi.org/10.4150/jpm.2025.00241
  • 185 View
  • 8 Download
AbstractAbstract PDF
Reversible solid oxide cells (rSOCs), which enable two-way conversion between electricity and hydrogen, have gained attention with the rise of hydrogen energy. However, foam-type current collectors in rSOC stacks exhibit poor structural controllability and limited electrode contact area. To address these limitations, this study aimed to convert spherical cobalt powders into flake-type morphology via high-energy ball milling, as a preliminary step toward fabricating flake-based current collectors. Milling parameters—specifically, the ball-to-powder ratio (BPR), milling time, and process control agent (PCA) content—were varied. At an 8:1 BPR, over 90% of the powder became flake-shaped after 8 hours, while extended milling caused cold welding. In contrast, a 10:1 BPR resulted in dominant fragmentation. The Burgio–Rojac model quantified energy input and defined the optimal range for flake formation. Increasing the PCA to 4 wt% delayed flake formation to 16 hours and induced cold welding, as shown by bimodal particle size distributions. These results support the development of Co-based current collectors for use in rSOCs.
Article image
[Korean]
Synthesis and Morphology Control of Needle Type 513 MHSH and Mg(OH)2 from Dolomite
Jiyeon Kim, HyunSeung Shim, Seong-Ju Hwang, YooJin Kim
J Powder Mater. 2025;32(5):399-405.   Published online October 31, 2025
DOI: https://doi.org/10.4150/jpm.2025.00227
  • 176 View
  • 2 Download
AbstractAbstract PDF
513 magnesium hydroxide sulfate hydrate (MHSH) and Mg(OH)₂ were synthesized by controlling the pH and concentration using a domestic resource, dolomite (CaMg(CO3)2), as the raw material. The MgSO₄ was extracted by treating dolomite with sulfuric acid under various conditions. Hexagonal plate-shaped Mg(OH)₂ and needle-like 513 MHSH were synthesized under the hydrothermal condition. The morphology of the synthesized materials was controlled by adjusting the pH (SO42-/OH- ratio) and hydrothermal reaction time. As the pH of the solution increased, the formation of plate-like structures became dominant, whereas lower pH values (higher SO42- concentration) led to needle-like forms. The results of the 513 MHSH, which was synthesized using reagents and sea bittern, are consistent with the synthesis conditions, and we observed changes in the length and aspect ratio of the needle-shaped structure in response to adjusting the hydrothermal reaction time.
Article image
[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
  • 832 View
  • 10 Download
AbstractAbstract 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.
Article image
[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
  • 1,500 View
  • 68 Download
AbstractAbstract 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.
Article image
[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
  • 551 View
  • 32 Download
AbstractAbstract 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.
Article image
[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
  • 735 View
  • 36 Download
AbstractAbstract 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.
Article image
[Korean]
Effect of the Initial Porosity of Needle Coke-Pitch Carbonized Blocks on Impregnation-Related Physical Properties
U-Sang Youn, Sang-Hye Lee, Jae-Seung Roh
J Powder Mater. 2025;32(2):138-144.   Published online April 30, 2025
DOI: https://doi.org/10.4150/jpm.2025.00038
  • 503 View
  • 11 Download
AbstractAbstract PDF
Carbonized blocks with different porosities were prepared by varying the particle size of the filler and subsequent impregnation. The impregnated carbonized blocks were re-carbonized. The use of smaller particles in the filler in the carbonized block was associated with larger porosity, smaller pore size, and a higher impregnation ratio. The block with the smallest average particle size (53 μm), CB-53, had a porosity of 35.9% and pores of approximately 40 μm, while the block with the largest average particle size (413 μm), CB-413, had a porosity of 30.5% and pores of approximately 150 μm. CB-53 had the highest bulk density, electrical resistivity, flexural strength, and impregnation ratio. This is due to the large porosity, which is believed to be due to the presence of more interfaces between particles during the re-carbonization of the impregnated carbonized block, resulting in a better pore-filling effect.
Article image
[Korean]
3D-Printed Stretchable Electrodes Enabled by a Titanium/Acrylamide-Based Hydrogel Nanocomposite
Se Jin Choi, Han Eol Lee
J Powder Mater. 2025;32(1):67-72.   Published online February 28, 2025
DOI: https://doi.org/10.4150/jpm.2024.00465
  • 615 View
  • 15 Download
AbstractAbstract PDF
Wearable electronics have been the focus of considerable interest in various fields, such as human-machine interfaces, soft robotics, and medical treatments, due to their flexibility, stretchability, and light weight. To address the shortcomings of existing metal thin film-based wearable devices, stretchable conductive polymers have been developed. In particular, double networking hydrogels are being actively studied as a polymer with a three-dimensional stereoscopic structure that can be patterned. Nonetheless, they have shortcomings such as poor electrical properties and cumbersome manufacturing processes, making it difficult to apply them in electronic devices. Herein, we report 3D-printed stretchable electrodes enabled by a titanium/polyacrylamide-alginate-based hydrogel nanocomposite. This research suggests the strategy for resolving the challenges of high costs and complex fabrication processes associated with stretchable electrode, providing a solution to accelerate the commercialization of wearable electronic devices.
Article image
[Korean]
Optimized Process and Mechanical and Electrical Analysis of Polyimide/Pb(Zr,Ti)O3-Based Flexible Piezoelectric Composites
Junki Lee, Sang-il Yoon, Hyunseung Kim, Chang Kyu Jeong
J Powder Mater. 2025;32(1):16-22.   Published online February 28, 2025
DOI: https://doi.org/10.4150/jpm.2024.00444
  • 776 View
  • 29 Download
AbstractAbstract PDF
Piezoelectric composites have attracted significant research interest as sustainable power sources for electronic devices due to their high mechanical stability and electrical output characteristics. This study investigated the optimal processing conditions for fabricating a flexible piezoelectric energy harvester based on Pb(Zr,Ti)O₃ (PZT) powder and a polyimide (PI) matrix composite. Various parameters, including the optimal mixing ratio of PI/PZT, ultrasonic treatment, homogenization, vacuum oven, and UV/O₃ treatment, were optimized to achieve a uniform piezoelectric composite. A PZT content of 30 wt% and 20 minutes of homogenization were identified as the most effective conditions for increasing the uniformity of the composite. The optimized composite exhibited a high piezoelectric coefficient, a typical P-E hysteresis loop, and dielectric properties, exhibiting a voltage output that adjusts in response to variations in the applied touch force. This study provides foundational data for the uniform fabrication of flexible piezoelectric energy harvesters and next-generation miniaturized electronic devices.
Article image
[English]
Design of Conductive Inks Containing Carbon Black and Silver Nanowires for Patternable Screen-Printing on Fabrics
Seokhwan Kim, Geumseong Lee, Jinwoo Park, Dahye Shin, Ki-Il Park, Kyoung Jin Jung, Yuho Min
J Powder Mater. 2024;31(6):500-507.   Published online December 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00409
  • 1,633 View
  • 46 Download
  • 1 Citations
AbstractAbstract PDF
This study developed conductive inks composed of carbon black (CB) and silver nanowires (Ag NWs) for cost-effective screen-printing on fabrics. The Ag NW density within the CB matrix was precisely controlled, achieving tunable electrical conductivity with minimal Ag NW usage. The resulting inks were successfully patterned into shapes such as square grids and circles on textile surfaces, demonstrating excellent conductivity and fidelity. Adding 19.9 wt% Ag NWs reduced sheet resistance by ~92% compared to CB-only inks, highlighting the effectiveness and potential of this hybrid approach for cost-effective, high-performance textile-based electronics. The one-dimensional morphology of Ag NWs facilitated the formation of conductive percolation networks, creating efficient electron pathways within the CB matrix even at low loadings. This work advances the field of CB-based conductive inks and provides a scalable and practical method for producing functional, patterned electronic textiles.

Citations

Citations to this article as recorded by  
  • Multifunctional Screen-Printed Conductive Inks: Design Principles, Performance Challenges, and Application Horizons
    Nahid Islam, Manisha Das, Bashir Ahmed Johan, Syed Shaheen Shah, Atif Saeed Alzahrani, Md. Abdul Aziz
    ACS Applied Electronic Materials.2025; 7(16): 7503.     CrossRef
Article image
[English]
High-Temperature Steam Oxidation Behavior of Silicide- or Aluminide- Coated Mo and Nb Refractory Metals
Woojin Lim, Je-Kyun Baek, JaeJoon Kim, Hyun Gil Kim, Ho Jin Ryu
J Powder Mater. 2024;31(6):546-555.   Published online December 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00381
  • 979 View
  • 18 Download
AbstractAbstract PDF
Refractory materials, such as molybdenum and niobium, are potential candidates for cladding material due to their high melting temperatures and desirable mechanical properties at higher temperatures than those of zirconium alloys. However, refractory materials have low resistance to oxidation at elevated temperatures. Therefore, this study examined silicide or aluminide surface coatings as protection against rapid oxidation of refractory materials at elevated temperatures for a potential accident-tolerant fuel cladding. Silicide or aluminide layers were formed on refractory metal substrates by using the pack cementation method. The steam oxidation behavior of both coated and uncoated samples was compared by thermogravimetric analysis at 1200°C. The weight changes of the coated samples were greatly reduced than those of uncoated samples. Microstructural analyses demonstrated that the silicide and aluminide layers were oxidized to form a protective surface oxide that prevented rapid oxidation of the refractory substrate at elevated temperatures.
Article image
[Korean]
Fabrication of SiCf/SiC Composites with a BN Interphase Prepared by the Wet Method
Kyung Ho Kim, Yoonsoo Han
J Powder Mater. 2024;31(6):530-536.   Published online December 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00339
  • 666 View
  • 14 Download
AbstractAbstract PDF
This study presents a cost-effective wet chemical coating process for fabricating a boron nitride (BN) interphase on silicon carbide (SiC) fibers, increasing the oxidation resistance and performance of SiCf/SiC ceramic matrix composites. Using urea as a precursor, optimal nitriding conditions were determined by adjusting the composition, concentration, and immersion time. X-ray diffraction analysis revealed distinct BN phase formation at 1300°C and 1500°C, while a mixture of BN and B₂O₃ was observed at 1200°C. HF treatment improved coating uniformity by removing SiO₂ layers formed during the de-sizing process. Optimization of the boric acid-to-urea molar ratio resulted in a uniform, 130-nm-thick BN layer. This study demonstrates that the wet coating process offers a viable and economical alternative to chemical vapor deposition for fabricating high-performance BN interphases in SiCf/SiC composites that are suitable for high-temperature applications.
Article image
[Korean]
Fabrication and High-Temperature Performance Evaluation of Light-Weight Insulation Materials and Coatings for Reusable Thermal Protection Systems
Min-Soo Nam, Jong-Il Kim, Jaesung Shin, Hyeonjun Kim, Bum-Seok Oh, Seongwon Kim
J Powder Mater. 2024;31(6):521-529.   Published online December 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00318
  • 1,199 View
  • 40 Download
AbstractAbstract PDF
Light-weight ceramic insulation materials and high-emissivity coatings were fabricated for reusable thermal protection systems (TPS). Alumina-silica fibers and boric acid were used to fabricate the insulation, which was heat treated at 1250 °C. High-emissivity coating of borosilicate glass modified with TaSi2, MoSi2, and SiB6 was applied via dip-and-spray coating methods and heat-treated at 1100°C. Testing in a high-velocity oxygen fuel environment at temperatures over 1100 °C for 120 seconds showed that the rigid structures withstood the flame robustly. The coating effectively infiltrated into the fibers, confirmed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. Although some oxidation of TaSi2 occurred, thereby increasing the Ta2O5 and SiO2 phases, no significant phase changes or performance degradation were observed. These results demonstrate the potential of these materials for reusable TPS applications in extreme thermal environments.
Critical Review
Article image
[English]
Epsilon Iron Oxide (ε-Fe2O3) as an Electromagnetic Functional Material: Properties, Synthesis, and Applications
Ji Hyeong Jeong, Hwan Hee Kim, Jung-Goo Lee, Youn-Kyoung Baek
J Powder Mater. 2024;31(6):465-479.   Published online December 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00290
  • 2,430 View
  • 76 Download
  • 1 Citations
AbstractAbstract PDF
Iron oxide (ε-Fe₂O₃) is emerging as a promising electromagnetic material due to its unique magnetic and electronic properties. This review focuses on the intrinsic properties of ε-Fe₂O₃, particularly its high coercivity, comparable to that of rare-earth magnets, which is attributed to its significant magnetic anisotropy. These properties render it highly suitable for applications in millimeter wave absorption and high-density magnetic storage media. Furthermore, its semiconducting behavior offers potential applications in photocatalytic hydrogen production. The review also explores various synthesis methods for fabricating ε-Fe₂O₃ as nanoparticles or thin films, emphasizing the optimization of purity and stability. By exploring and harnessing the properties of ε-Fe₂O₃, this study aims to contribute to the advancement of next-generation electromagnetic materials with potential applications in 6G wireless telecommunications, spintronics, high-density data storage, and energy technologies.

Citations

Citations to this article as recorded by  
  • Superparamagnetism of Baked Clays Containing Polymorphs of Iron Oxides: Experimental Study and Theoretical Modeling
    Petr Kharitonskii, Andrei Krasilin, Nadezhda Belskaya, Svetlana Yanson, Nikita Bobrov, Andrey Ralin, Kamil Gareev, Nikita Zolotov, Dmitry Zaytsev, Elena Sergienko
    Magnetochemistry.2025; 11(12): 103.     CrossRef
Research Articles
Article image
[Korean]
Effect of TiO2 Content on High-Temperature Degradation Behavior of Nd2O3 and Yb2O3 Doped YSZ Composite Materials
Gye-Won Lee, Seonung Choi, Tae-jun Park, Jong-il Kim, In-hwan Lee, Yoon-seok Oh
J Powder Mater. 2024;31(5):431-436.   Published online October 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00269
  • 529 View
  • 7 Download
AbstractAbstract PDF
Hot section components of gas turbines are exposed to a high operating temperature environment. To protect these components, thermal barrier coatings (TBC) are applied to their surfaces. Yttria-stabilized zirconia (YSZ), which is widely used as a TBC material, faces limitations at temperatures above 1200℃. To mitigate these issues, research has focused on adding lanthanide rare earth oxides and tetravalent oxides to prevent the phase-transformation of the monoclinic phase in zirconia. This study investigated the effects of varying TiO2 content in Nd2O3 and Yb2O3 co-doped YSZ composites. Increasing TiO2 content effectively suppressed formation of the monoclinic phase and increased the thermal degradation resistance compared to YSZ in environments over 1200℃. These findings will aid in developing more thermally stable and efficient TBC materials for application in high-temperature environments.
Article image
[Korean]
Inter-laminar Strength of NITE-SiC/SiC Composites With Various Fiber Reinforcing Architecture
Jong-il Kim
J Powder Mater. 2024;31(5):437-444.   Published online October 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00248
  • 671 View
  • 10 Download
AbstractAbstract PDF
The mechanical performance of SiC/SiC composites is significantly influenced by the architecture of fiber reinforcement. Among the various fabrication methods, the nano-powder infiltration transition/eutectic (NITE) process is a promising technique that is capable of achieving a dense and stoichiometric SiC matrix. The reinforcement architecture, such as cross-ply (CP) or woven prepreg (WP), is determined during the preform stage of the NITE process, which is crucial in determining the mechanical properties of SiC/SiC composites. In this study, the tensile test and double notch shear (DNS) test were conducted using NITE-SiC/SiC composites to investigate the effect of the fiber reinforcing architecture on the fracture mechanism of SiC/SiC composites. The tensile strength and maximum shear strength of both CP and WP specimens were nearly identical. However, other mechanical properties, particularly those of CP specimens, exhibited significant variability. A comparison of fracture surfaces and load-displacement curve analyses from the DNS tests revealed that the cross points of the longitudinal or transverse fibers act as obstacles to both deformation and crack propagation. These obstacles were found to be more densely distributed in WP specimens than in CP specimens. The variability observed in the mechanical properties of CP specimens is likely due to size effects caused by the sparser distribution of these obstacles compared to the WP specimens.
Article image
[English]
Machine Learning Modeling of the Mechanical Properties of Al2024-B4C Composites
Maurya A. K., Narayana P. L., Wang X.-S., Reddy N. S.
J Powder Mater. 2024;31(5):382-389.   Published online October 31, 2024
DOI: https://doi.org/10.4150/jpm.2024.00234
  • 1,000 View
  • 26 Download
AbstractAbstract PDF
Aluminum-based composites are in high demand in industrial fields due to their light weight, high electrical conductivity, and corrosion resistance. Due to its unique advantages for composite fabrication, powder metallurgy is a crucial player in meeting this demand. However, the size and weight fraction of the reinforcement significantly influence the components' quality and performance. Understanding the correlation of these variables is crucial for building high-quality components. This study, therefore, investigated the correlations among various parameters—namely, milling time, reinforcement ratio, and size—that affect the composite’s physical and mechanical properties. An artificial neural network model was developed and showed the ability to correlate the processing parameters with the density, hardness, and tensile strength of Al2024-B4C composites. The predicted index of relative importance suggests that the milling time has the most substantial effect on fabricated components. This practical insight can be directly applied in the fabrication of high-quality Al2024-B4C composites.
Article image
[Korean]
Characterization of Compacted and Pressureless Sintered Parts for Molybdenum Oxide Powder according to Hydrogen Reduction Temperature
Jong Hoon Lee, Kun-Jae Lee
J Powder Mater. 2024;31(4):336-341.   Published online August 30, 2024
DOI: https://doi.org/10.4150/jpm.2024.00241
  • 960 View
  • 14 Download
  • 1 Citations
AbstractAbstract PDF
Molybdenum, valued for its high melting point and exceptional physical and chemical properties, is studied in diverse fields such as electronics, petrochemicals, and aviation. Among molybdenum oxides, molybdenum dioxide stands out for its higher electrical conductivity than other transition metal oxides due to its structural characteristics, exhibiting metallic properties. It is applied as pellets to gas sensors, semiconductors, and secondary batteries for its properties. Thus, research on molybdenum dioxide compaction and pressureless sintering is necessary, yet research on pressureless sintering is currently insufficient. This study synthesized MoO₃ powder via solution combustion synthesis and reduced it using the 3% hydrogen/argon gas mixture to investigate the effect of reduction temperature on the powder. Additionally, the reduced powder was compacted and subjected to pressureless sintering with temperature as a variable. The density and the microstructure of brown parts were analyzed and discussed.

Citations

Citations to this article as recorded by  
  • High-sensitivity optical fiber hydrogen sensing with MoO3/PANI/Pd nanocomposite
    Mohammed M. Alkhabet, Saad H. Girei, Ammar H. Farhan, Fatimah F. Hashim, Jaafar A. Jaafar, Husam K. Salih, Manar F. Abbood, Mohd H. Yaacob
    Materials Science in Semiconductor Processing.2025; 200: 110021.     CrossRef
Article image
[Korean]
Fabrication of 3D Aligned h-BN based Polymer Composites with Enhanced Mechanical Properties for Battery Housing
Kiho Song, Hyunseung Song, Sang In Lee, Changui Ahn
J Powder Mater. 2024;31(4):329-335.   Published online August 30, 2024
DOI: https://doi.org/10.4150/jpm.2024.00220
  • 1,121 View
  • 31 Download
AbstractAbstract PDFSupplementary Material
As the demand for electric vehicles increases, the stability of batteries has become one of the most significant issues. The battery housing, which protects the battery from external stimuli such as vibration, shock, and heat, is the crucial element in resolving safety problems. Conventional metal battery housings are being converted into polymer composites due to their lightweight and improved corrosion resistance to moisture. The transition to polymer composites requires high mechanical strength, electrical insulation, and thermal stability. In this paper, we proposes a high-strength nanocomposite made by infiltrating epoxy into a 3D aligned h-BN structure. The developed 3D aligned h-BN/epoxy composite not only exhibits a high compressive strength (108 MPa) but also demonstrates excellent electrical insulation and thermal stability, with a stable electrical resistivity at 200 °C and a low thermal expansion coefficient (11.46ⅹppm/℃), respectively.
Critical Review
Article image
[English]
A Review of Inorganic Solid Electrolytes for All-Solid-State Lithium Batteries: Challenges and Progress
Seul Ki Choi, Jaehun Han, Gi Jeong Kim, Yeon Hee Kim, Jaewon Choi, MinHo Yang
J Powder Mater. 2024;31(4):293-301.   Published online August 30, 2024
DOI: https://doi.org/10.4150/jpm.2024.00206
  • 8,327 View
  • 200 Download
  • 3 Citations
AbstractAbstract PDF
All-solid-state lithium batteries (ASSLBs) are receiving attention as a prospective next-generation secondary battery technology that can reduce the risk of commercial lithium-ion batteries by replacing flammable organic liquid electrolytes with non-flammable solid electrolytes. The practical application of ASSLBs requires developing robust solid electrolytes that possess ionic conductivity at room temperature on a par with that of organic liquids. These solid electrolytes must also be thermally and chemically stable, as well as compatible with electrode materials. Inorganic solid electrolytes, including oxide and sulfide-based compounds, are being studied as promising future candidates for ASSLBs due to their higher ionic conductivity and thermal stability than polymer electrolytes. Here, we present the challenges currently facing the development of oxide and sulfide-based solid electrolytes, as well as the research efforts underway aiming to resolve these challenges.

Citations

Citations to this article as recorded by  
  • A facile synthesis of bulk LiPON in solution for solid-state electrolytes
    Osma J. Gomez, Adam Antar, Alex T. Hall, Leopoldo Tapia-Aracayo, Joshua Seo, Nam Kim, Zihan Sun, Ryan Lim, Fu Chen, Yue Li, John Cumings, Gary Rubloff, Sang Bok Lee, David Stewart, Yang Wang
    Journal of Materials Chemistry A.2025; 13(34): 28368.     CrossRef
  • Uniform lithium deposition using Cu teepee structures for anode-free lithium metal batteries
    Seo Yun Jung, Jaehun Han, Seul Ki Choi, Se Youn Cho, Jong Ho Won, Jaewon Choi, Minho Yang
    Chemical Engineering Journal.2025; 522: 167302.     CrossRef
  • Garnet-type LLZO electrolytes for solid-state lithium batteries: Interfaces, conductivity, in-situ processing, and industrial prospects
    Kaleab Habtamu Ayalew, Nithyadharseni Palaniyandy, Mkhulu K. Mathe, Phumlani F. Msomi
    Chemical Engineering Journal.2025; 524: 168098.     CrossRef
Special Article
Article image
[English]
Trends in Materials Modeling and Computation for Metal Additive Manufacturing
Seoyeon Jeon, Hyunjoo Choi
J Powder Mater. 2024;31(3):213-219.   Published online June 27, 2024
DOI: https://doi.org/10.4150/jpm.2024.00150
  • 2,044 View
  • 67 Download
  • 2 Citations
AbstractAbstract PDF
Additive Manufacturing (AM) is a process that fabricates products by manufacturing materials according to a three-dimensional model. It has recently gained attention due to its environmental advantages, including reduced energy consumption and high material utilization rates. However, controlling defects such as melting issues and residual stress, which can occur during metal additive manufacturing, poses a challenge. The trial-and-error verification of these defects is both time-consuming and costly. Consequently, efforts have been made to develop phenomenological models that understand the influence of process variables on defects, and mechanical/electrical/thermal properties of geometrically complex products. This paper introduces modeling techniques that can simulate the powder additive manufacturing process. The focus is on representative metal additive manufacturing processes such as Powder Bed Fusion (PBF), Direct Energy Deposition (DED), and Binder Jetting (BJ) method. To calculate thermal-stress history and the resulting deformations, modeling techniques based on Finite Element Method (FEM) are generally utilized. For simulating the movements and packing behavior of powders during powder classification, modeling techniques based on Discrete Element Method (DEM) are employed. Additionally, to simulate sintering and microstructural changes, techniques such as Monte Carlo (MC), Molecular Dynamics (MD), and Phase Field Modeling (PFM) are predominantly used.

Citations

Citations to this article as recorded by  
  • Review of “Integrated Computer-Aided Process Engineering Session in the 17th International Symposium on Novel and Nano Materials (ISNNM, 14–18 November 2022)”
    Yeon-Joo Lee, Pil-Ryung Cha, Hyoung-Seop Kim, Hyun-Joo Choi
    MATERIALS TRANSACTIONS.2025; 66(1): 144.     CrossRef
  • 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
    Journal of Powder Materials.2025; 32(3): 244.     CrossRef
Research Articles
Article image
[English]
Investigation of the Thermal-to-Electrical Properties of Transition Metal-Sb Alloys Synthesized for Thermoelectric Applications
Jong Min Park, Seungki Jo, Sooho Jung, Jinhee Bae, Linh Ba Vu, Kwi-Il Park, Kyung Tae Kim
J Powder Mater. 2024;31(3):236-242.   Published online June 27, 2024
DOI: https://doi.org/10.4150/jpm.2024.00031
  • 1,378 View
  • 43 Download
  • 2 Citations
AbstractAbstract PDF
The development of thermoelectric (TE) materials to replace Bi2Te3 alloys is emerging as a hot issue with the potential for wider practical applications. In particular, layered Zintl-phase materials, which can appropriately control carrier and phonon transport behaviors, are being considered as promising candidates. However, limited data have been reported on the thermoelectric properties of metal-Sb materials that can be transformed into layered materials through the insertion of cations. In this study, we synthesized FeSb and MnSb, which are used as base materials for advanced thermoelectric materials. They were confirmed as single-phase materials by analyzing X-ray diffraction patterns. Based on electrical conductivity, the Seebeck coefficient, and thermal conductivity of both materials characterized as a function of temperature, the zT values of MnSb and FeSb were calculated to be 0.00119 and 0.00026, respectively. These properties provide a fundamental data for developing layered Zintl-phase materials with alkali/alkaline earth metal insertions.

Citations

Citations to this article as recorded by  
  • Improving thermoelectric properties of CuMnSb alloys via strategic alloying with magnetic MnSb and Cu
    Jong Min Park, Seungki Jo, Soo-ho Jung, Jinhee Bae, Linh Ba Vu, Jihun Yu, Kyung Tae Kim
    Materials Letters.2025; 381: 137796.     CrossRef
  • Highly deformable and hierarchical 3D composite sponge for versatile thermoelectric energy conversion
    Jong Min Park, Changyeon Baek, Min-Ku Lee, Nagamalleswara Rao Alluri, Gyoung-Ja Lee, Kyung Tae Kim, Kwi-Il Park
    Applied Surface Science.2025; 692: 162730.     CrossRef
Article image
[English]
Bandgap Tuning and Quenching Effects of In(Zn)P@ZnSe@ZnS Quantum Dots
Sang Yeon Lee, Su Hyun Park, Gyungsu Byun, Chang-Yeoul Kim
J Powder Mater. 2024;31(3):226-235.   Published online June 27, 2024
DOI: https://doi.org/10.4150/jpm.2024.00003
  • 2,382 View
  • 42 Download
  • 1 Citations
AbstractAbstract PDF
InP quantum dot (QDs) have attracted researchers’ interest due to their applicability in quantum dot light-emitting displays (QLED) or biomarkers for detecting cancers or viruses. The surface or interface control of InP QD core/shell has substantially increased quantum efficiency, with a quantum yield of 100% reached by introducing HF to inhibit oxide generation. In this study, we focused on the control of bandgap energy of quantum dots by changing the Zn/(In+Zn) ratio in the In(Zn)P core. Zinc incorporation can change the photoluminescent light colors of green, yellow, orange, and red. Diluting a solution of as-synthesized QDs by more than 100 times did not show any quenching effects by the Förster resonance energy transfer phenomenon between neighboring QDs.

Citations

Citations to this article as recorded by  
  • Enhancing luminescence of QD thin films, polymer composite films, and LED devices by nanostructures
    Hongcheng Yang, Junjie Hao, Mingyu Sun, Yujie Song, Kai Wang, Yujie Song, Xiao Wei Sun, Wenda Zhang
    The Innovation.2025; : 101121.     CrossRef
Article image
[English]
The Effect of TiO2 Addition on Low-temperature Sintering Behaviors in a SnO2-CoO-CuO System
Jae-Sang Lee, Kyung-Sik Oh, Yeong-Kyeun Paek
J Powder Mater. 2024;31(2):146-151.   Published online April 30, 2024
DOI: https://doi.org/10.4150/jpm.2024.00024
  • 1,006 View
  • 18 Download
AbstractAbstract PDF
Pure SnO2 has proven very difficult to densify. This poor densification can be useful for the fabrication of SnO2 with a porous microstructure, which is used in electronic devices such as gas sensors. Most electronic devices based on SnO2 have a porous microstructure, with a porosity of > 40%. In pure SnO2, a high sintering temperature of approximately 1300C is required to obtain > 40% porosity. In an attempt to reduce the required sintering temperature, the present study investigated the low-temperature sinterability of a current system. With the addition of TiO2, the compositions of the samples were Sn1-xTixO2-CoO(0.3wt%)-CuO(2wt%) in the range of x ≤ 0.04. Compared to the samples without added TiO2, densification was shown to be improved when the samples were sintered at 950C. The dominant mass transport mechanism appears to be grain-boundary diffusion during heat treatment at 950C.
Article image
[Korean]
Inorganic Compound and Cycloserine Composite Particles for Improved Stability
Dongwon Kim, Heeseo Kim, Hongjun Yoon, Hyuk Jun Cho, Sung Giu Jin
J Powder Mater. 2024;31(2):126-131.   Published online April 30, 2024
DOI: https://doi.org/10.4150/jpm.2024.00002
  • 1,643 View
  • 30 Download
AbstractAbstract PDF
The aim of this study was to improve the chemical stability of cycloserine containing organic and inorganic compounds. Composite particles were manufactured with a 1:1 weight ratio of organic/inorganic compounds and cycloserine. The influence of organic/inorganic compounds on the stability of cycloserine was investigated under accelerated stress conditions at 60°C/75% RH for 24 hours. In addition, the properties of the composite particles were evaluated using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and the dissolution of the drug was assessed by preparing it as a hard capsule. Among the organic and inorganic compounds investigated, calcium hydroxide most improved the stability of cycloserine under accelerated stress conditions (53.3 ± 2.2% vs 1.7 ± 0.2%). DSC results confirmed the compatibility between calcium hydroxide and the cycloserine, and SEM results confirmed that it was evenly distributed around the cycloserine. Calcium hydroxide also showed more than 90% cycloserine dissolution within 15 minutes. Therefore, the calcium hydroxide and cycloserine composite particles may be candidates for cycloserine oral pharmaceuticals with enhanced drug stability.
Article image
[Korean]
Fabrication of Bi2Te2.5Se0.5 by Combining Oxide-reduction and Compressive-forming Process and Its Thermoelectric Properties
Young Soo Lim, Gil-Geun Lee
J Powder Mater. 2024;31(1):50-56.   Published online February 28, 2024
DOI: https://doi.org/10.4150/KPMI.2024.31.1.50
  • 943 View
  • 19 Download
PDF
Article image
[Korean]
Fabrication of Ti-Mo Core-shell Powder and Sintering Properties for Application as a Sputtering Target
Won Hee Lee, Chun Woong Park, Heeyeon Kim, Yuncheol Ha, Jongmin Byun, Young Do Kim
J Powder Mater. 2024;31(1):43-49.   Published online February 28, 2024
DOI: https://doi.org/10.4150/KPMI.2024.31.1.43
  • 1,372 View
  • 36 Download
PDF
Article image
[Korean]
Effect of Abnormal Grain Growth on Ionic Conductivity in LATP
Hyungik Choi, Yoonsoo Han
J Powder Mater. 2024;31(1):23-29.   Published online February 28, 2024
DOI: https://doi.org/10.4150/KPMI.2024.31.1.23
  • 2,472 View
  • 62 Download
  • 2 Citations
PDF

Citations

Citations to this article as recorded by  
  • Temperature-dependent microstructural evolution in a compositionally complex solid electrolyte: The role of a grain boundary transition
    Shu-Ting Ko, Chaojie Du, Huiming Guo, Hasti Vahidi, Jenna L. Wardini, Tom Lee, Yi Liu, Jingjing Yang, Francisco Guzman, Timothy J. Rupert, William J. Bowman, Shen J. Dillon, Xiaoqing Pan, Jian Luo
    Journal of Advanced Ceramics.2025; 14(3): 9221047.     CrossRef
  • Effect of bimodal particle size distribution on Li1.5Al0.5Ti1.5(PO4)3 solid electrolytes: Microstructures and electrochemical properties
    Gi Jeong Kim, Yeon Hee Kim, Seul Ki Choi, Jong Won Bae, Kun-Jae Lee, Minho Yang
    Powder Technology.2025; 466: 121407.     CrossRef
Review Paper
Article image
[English]
Research Trends in Electromagnetic Shielding using MXene-based Composite Materials
Siyeon Kim, Jongmin Byun
J Powder Mater. 2024;31(1):57-76.   Published online February 28, 2024
DOI: https://doi.org/10.4150/KPMI.2024.31.1.57
  • 6,525 View
  • 145 Download
  • 3 Citations
AbstractAbstract PDF

Recent advancements in electronic devices and wireless communication technologies, particularly the rise of 5G, have raised concerns about the escalating electromagnetic pollution and its potential adverse impacts on human health and electronics. As a result, the demand for effective electromagnetic interference (EMI) shielding materials has grown significantly. Traditional materials face limitations in providing optimal solutions owing to inadequacy and low performance due to small thickness. MXene-based composite materials have emerged as promising candidates in this context owing to their exceptional electrical properties, high conductivity, and superior EMI shielding efficiency across a broad frequency range. This review examines the recent developments and advantages of MXene-based composite materials in EMI shielding applications, emphasizing their potential to address the challenges posed by electromagnetic pollution and to foster advancements in modern electronics systems and vital technologies.

Citations

Citations to this article as recorded by  
  • Designing dual phase hexaferrite (SrFe12O19) – Perovskite (La0.5Nd0.5FeO3) composites for enhanced electromagnetic wave absorption and band gap modulation
    Pramod D. Mhase, Varsha C. Pujari, Santosh S. Jadhav, Abdullah G. Al-Sehemi, Sarah Alsobaie, Sunil M. Patange
    Composites Communications.2025; 54: 102284.     CrossRef
  • Microstructure tailoring of Nb-based MAX phase by low temperature synthesis with layer-structured Nb2C powder and molten salt method
    Chaehyun Lim, Wonjune Choi, Jongmin Byun
    Materials Characterization.2025; 225: 115106.     CrossRef
  • Fabrication of MOF@MXene composites via surface modification of MXene under acidic conditions
    Ji-Haeng Jeong, Woong-Ryeol Yu
    Functional Composites and Structures.2025; 7(2): 025006.     CrossRef
Articles
Article image
[Korean]
Preparation and Evaluation of Ketoconazole-loaded Solid-SNEDDS (Self-Nanoemulsifying Drug Delivery System) using Various Solidification Carriers
Da Young Song, Kyeong Soo Kim
J Powder Mater. 2023;30(6):493-501.   Published online December 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.6.493
  • 805 View
  • 10 Download
AbstractAbstract PDF

This study aimed to develop a solid self-nanoemulsifying drug delivery system (solid-SNEDDS) to enhance the formulation of ketoconazole (KTZ), a BCS Class II drug with poor solubility. Ketoconazole, which is insoluble above pH 3, requires solubilization for effective delivery. This SNEDDS comprises oil, surfactant, and co-surfactant, which spontaneously emulsify in the gastrointestinal tract environment to form nanoemulsions with droplet sizes less than 100 nm. The optimal SNE-vehicle composition of oleic acid, TPGS, and PEG 400 at a 10:80:10 weight ratio was determined based on the smallest droplet size achieved. This composition was used to prepare liquid SNEDDS containing ketoconazole. The droplet size and polydispersity index (PDI) of the resulting liquid SNEDDS were analyzed. Subsequently, solid-SNEDDS was fabricated using a spray-drying method with solidifying carriers such as silicon dioxide, crospovidone, and magnesium alumetasilicate. The physicochemical properties of the solid-SNEDDS were characterized by scanning electron microscopy and powder X-ray diffraction, and its solubility, droplet size, and PDI were evaluated. In particular, the solid-SNEDDS containing ketoconazole and crospovidone in a 2:1 weight ratio exhibited significantly enhanced solubility, highlighting its potential for improved medication adherence and dissolution rates.

Article image
[Korean]
Combinatorial Experiment for Al-6061 and Al-12Si alloy Based on Directed Energy Deposition (DED) Process
Seoyeon Jeon, Suwon Park, Yongwook Song, Jiwon Park, Hyunyoung Park, Boram Lee, Hyunjoo Choi
J Powder Mater. 2023;30(6):463-469.   Published online December 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.6.463
  • 1,717 View
  • 44 Download
  • 4 Citations
AbstractAbstract PDF

Aluminum alloys, known for their high strength-to-weight ratios and impressive electrical and thermal conductivities, are extensively used in numerous engineering sectors, such as aerospace, automotive, and construction. Recently, significant efforts have been made to develop novel aluminum alloys specifically tailored for additive manufacturing. These new alloys aim to provide an optimal balance between mechanical properties and thermal/ electrical conductivities. In this study, nine combinatorial samples with various alloy compositions were fabricated using direct energy deposition (DED) additive manufacturing by adjusting the feeding speeds of Al6061 alloy and Al-12Si alloy powders. The effects of the alloying elements on the microstructure, electrical conductivity, and hardness were investigated. Generally, as the Si and Cu contents decreased, electrical conductivity increased and hardness decreased, exhibiting trade-off characteristics. However, electrical conductivity and hardness showed an optimal combination when the Si content was adjusted to below 4.5 wt%, which can sufficiently suppress the grain boundary segregation of the α- Si precipitates, and the Cu content was controlled to induce the formation of Al2Cu precipitates.

Citations

Citations to this article as recorded by  
  • Development of Aluminum Alloys for Additive Manufacturing Using Machine Learning
    Sungbin An, Juyeon Han, Seoyeon Jeon, Dowon Kim, Jae Bok Seol, Hyunjoo Choi
    Journal of Powder Materials.2025; 32(3): 202.     CrossRef
  • Trends in Materials Modeling and Computation for Metal Additive Manufacturing
    Seoyeon Jeon, Hyunjoo Choi
    journal of Korean Powder Metallurgy Institute.2024; 31(3): 213.     CrossRef
  • The Challenges and Advances in Recycling/Re-Using Powder for Metal 3D Printing: A Comprehensive Review
    Alex Lanzutti, Elia Marin
    Metals.2024; 14(8): 886.     CrossRef
  • Microstructural Effects on the Mechanical Properties of Ti-6Al-4V Fabricated by Direct Energy Deposition
    Juho Kim, Seoyeon Jeon, Hwajin Park, Taeyoel Kim, Hyunjoo Choi
    Journal of Powder Materials.2024; 31(4): 302.     CrossRef
Article image
[Korean]
Tribological Behavior Analysis of WC-Ni-Cr + Cr3C2 and WC-Ni-Cr + YSZ Coatings Sprayed by HVOF
Tae-Jun Park, Gye-Won Lee, Yoon-Suk Oh
J Powder Mater. 2023;30(5):415-423.   Published online October 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.5.415
  • 805 View
  • 3 Download
AbstractAbstract PDF

With the increasing attention to environmental pollution caused by particulate matter globally, the automotive industry has also become increasingly interested in particulate matter, especially particulate matter generated by automobile brake systems. Here, we designed a coating composition and analyzed its mechanical properties to reduce particulate matter generated by brake systems during braking of vehicles. We designed a composition to check the mechanical properties change by adding Cr3C2 and YSZ to the WC-Ni-Cr composite composition. Based on the designed composition, coating samples were manufactured, and the coating properties were analyzed by Vickers hardness and ball-on-disk tests. As a result of the experiments, we found that the hardness and friction coefficient of the coating increased as the amount of Cr3C2 added decreased. Furthermore, we found that the hardness of the coating layer decreased when YSZ was added at 20vol%, but the friction coefficient was higher than the composition with Cr3C2 addition.

Article image
[Korean]
Phase Formation and Mechanical Property of YSZ‒30 vol.% WC Composite Ceramics Fabricated by Hot Pressing
Jin-Kwon Kim, Jae-Hyeong Choi, Nahm Sahn, Sung-Soo Ryu, Seongwon Kim
J Powder Mater. 2023;30(5):409-414.   Published online October 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.5.409
  • 491 View
  • 5 Download
AbstractAbstract PDF

YSZ (Y2O3-stabilized zirconia)-based ceramics have excellent mechanical properties, such as high strength and wear resistance. In the application, YSZ is utilized in the bead mill, a fine-grinding process. YSZ-based parts, such as the rotor and pin, can be easily damaged by continuous application with high rpm in the bead mill process. In that case, adding WC particles improves the tribological and mechanical properties. YSZ-30 vol.% WC composite ceramics are manufactured via hot pressing under different pressures (10/30/60 MPa). The hot-pressed composite ceramics measure the physical properties, such as porosity and bulk density values. In addition, the phase formation of these composite ceramics is analyzed and discussed with those of physical properties. For the increased applied pressure of hot pressing, the tetragonality of YSZ and the crystallinity of WC are enhanced. The mechanical properties indicate an improved tendency with the increase in the applied pressure of hot pressing.

Article image
[Korean]
Synthesis of Carbon Coated Nickel Cobalt Sulfide Yolk-shell Microsphere and Their Application as Anode Materials for Sodium Ion Batteries
Hyo Yeong Seo, Gi Dae Park
J Powder Mater. 2023;30(5):387-393.   Published online October 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.5.387
  • 623 View
  • 13 Download
AbstractAbstract PDF

Transition metal chalcogenides are promising cathode materials for next-generation battery systems, particularly sodium-ion batteries. Ni3Co6S8-pitch-derived carbon composite microspheres with a yolk-shell structure (Ni3Co6S8@C-YS) were synthesized through a three-step process: spray pyrolysis, pitch coating, and post-heat treatment process. Ni3Co6S8@C-YS exhibited an impressive reversible capacity of 525.2 mA h g-1 at a current density of 0.5 A g-1 over 50 cycles when employed as an anode material for sodium-ion batteries. However, Ni3Co6S8 yolk shell nanopowder (Ni3Co6S8-YS) without pitch-derived carbon demonstrated a continuous decrease in capacity during charging and discharging. The superior sodium-ion storage properties of Ni3Co6S8@C-YS were attributed to the pitchderived carbon, which effectively adjusted the size and distribution of nanocrystals. The carbon-coated yolk-shell microspheres proposed here hold potential for various metal chalcogenide compounds and can be applied to various fields, including the energy storage field.

Article image
[Korean]
Fabrication of Polymer Composite with Enhanced Insulation and Mechanical Properties using Aluminum Borate Nanowhiskers
Junhyeok Choi, Sangin Lee, Kiho Song, Taekyung Kim, Changui Ahn
J Powder Mater. 2023;30(4):356-362.   Published online August 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.4.356
  • 800 View
  • 2 Download
  • 1 Citations
AbstractAbstract PDF

Inorganic-organic composites find extensive application in various fields, including electronic devices and light-emitting diodes. Notably, encapsulation technologies are employed to shield electronic devices (such as printed circuit boards and batteries) from stress and moisture exposure while maintaining electrical insulation. Polymer composites can be used as encapsulation materials because of their controllable mechanical and electrical properties. In this study, we propose a polymer composite that provides good electrical insulation and enhanced mechanical properties. This is achieved by using aluminum borate nanowhiskers (ABOw), which are fabricated using a facile synthesis method. The ABOw fillers are created via a hydrothermal method using aluminum chloride and boric acid. We confirm that the synthesis occurs in various morphologies based on the molar ratio. Specifically, nanowhiskers are synthesized at a molar ratio of 1:3 and used as fillers in the composite. The fabricated ABOw/epoxy composites exhibit a 48.5% enhancement in mechanical properties, similar to those of pure epoxy, while maintaining good electrical insulation.

Citations

Citations to this article as recorded by  
  • Fabrication of Al18B4O33 Spherical Powder with Increased Fluidity via Control of B2O3 Particle Size and Distribution
    Kiho Song, Sang in Lee, Hyunseung Song, Changui Ahn
    Journal of Powder Materials.2024; 31(6): 513.     CrossRef
Article image
[Korean]
Epoxy-Based Siloxane/Silica Composites for Electronic Packaging by Composition and Molecular Structure of Siloxane, and Analysis of Changes in Properties
Junho Jang, Dong Jun Kang, Hyeon-Gyun Im
J Powder Mater. 2023;30(4):346-355.   Published online August 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.4.346
  • 944 View
  • 10 Download
  • 2 Citations
AbstractAbstract PDF

Epoxy-based composites find extensive application in electronic packaging due to their excellent processability and insulation properties. However, conventional epoxy-based polymers exhibit limitations in terms of thermal properties and insulation performance. In this study, we develop epoxy-based siloxane/silica composites that enhance the thermal, mechanical, and insulating properties of epoxy resins. This is achieved by employing a sol–gelsynthesized siloxane hybrid and spherical fused silica particles. Herein, we fabricate two types of epoxy-based siloxane/ silica composites with different siloxane molecular structures (branched and linear siloxane networks) and investigate the changes in their properties for different compositions (with or without silica particles) and siloxane structures. The presence of a branched siloxane structure results in hardness and low insulating properties, while a linear siloxane structure yields softness and highly insulating properties. Both types of epoxy-based siloxane/silica composites exhibit high thermal stability and low thermal expansion. These properties are considerably improved by incorporating silica particles. We expect that our developed epoxy-based composites to hold significant potential as advanced electronic packaging materials, offering high-performance and robustness.

Citations

Citations to this article as recorded by  
  • Toughening epoxy matrices via elastomeric blending for enhanced compatibility with auxetic reinforcements in composites
    Usama Khalid, Shiza Shahid, Muhammad Bilal Qadir, Mumtaz Ali, Zubair Khaliq, Aamir Naseem Satti, Zaheer Anwar Randhawa, Danish Umer
    Mechanics Based Design of Structures and Machines.2025; : 1.     CrossRef
  • Enhanced Epoxy Composites Reinforced by 3D-Aligned Aluminum Borate Nanowhiskers
    Hyunseung Song, Kiho Song, Haejin Hwang, Changui Ahn
    Materials.2024; 17(19): 4727.     CrossRef
Article image
[Korean]
Controlling Particle Size of Recycled Copper Oxide Powder for Copper Thermite Welding Characteristics
Hansung Lee, Minsu Kim, Byungmin Ahn
J Powder Mater. 2023;30(4):332-338.   Published online August 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.4.332
  • 724 View
  • 8 Download
  • 1 Citations
AbstractAbstract PDF

Thermite welding is an exceptional process that does not require additional energy supplies, resulting in welded joints that exhibit mechanical properties and conductivity equivalent to those of the parent materials. The global adoption of thermite welding is growing across various industries. However, in Korea, limited research is being conducted on the core technology of thermite welding. Currently, domestic production of thermite powder in Korea involves recycling copper oxide (CuO). Unfortunately, controlling the particle size of waste CuO poses challenges, leading to the unwanted formation of pores and cracks during thermite welding. In this study, we investigate the influence of powder particle size on thermite welding in the production of Cu-thermite powder using waste CuO. We conduct the ball milling process for 0.5–24 h using recycled CuO. The evolution of the powder shape and size is analyzed using particle size analysis and scanning electron microscopy (SEM). Furthermore, we examine the thermal reaction characteristics through differential scanning calorimetry. Additionally, the microstructures of the welded samples are observed using optical microscopy and SEM to evaluate the impact of powder particle size on weldability. Lastly, hardness measurements are performed to assess the strengths of the welded materials.

Citations

Citations to this article as recorded by  
  • Friction Welding of Casted SCM440 and Sintered F-05-140 Dissimilar Steels and Their Joint Properties under Various Welding Conditions
    Jisung Lee, Hansung Lee, Eunhyo Song, Byungmin Ahn
    Journal of Powder Materials.2024; 31(5): 414.     CrossRef
Article image
[Korean]
Size Control of Iron Oxide (Fe3O4) Nanoclusters according to Reaction Factors and Consequent Change in Their Magnetic Attraction
Sanghoon Lee, Arim Byun, Jin-sil Choi
J Powder Mater. 2023;30(4):297-304.   Published online August 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.4.297
  • 764 View
  • 13 Download
  • 1 Citations
AbstractAbstract PDF

Iron oxide (Fe2O3) nanoclusters exhibit significant potential in the biomedical and pharmaceutical fields due to their strong magnetic properties, stability in solutions, and compatibility with living systems. They excel in magnetic separation processes, displaying high responsiveness to external magnetic fields. In contrast to conventional Fe2O3 nanoparticles that can aggregate in aqueous solutions due to their ferrimagnetic properties, these nanoclusters, composed of multiple nanoparticles, maintain their magnetic traits even when scaled to hundreds of nanometers. In this study, we develop a simple method using solvothermal synthesis to precisely control the size of nanoclusters. By adjusting precursor materials and reducing agents, we successfully control the particle sizes within the range of 90 to 420 nm. Our study not only enhances the understanding of nanocluster creation but also offers ways to improve their properties for applications such as magnetic separation. This is supported by our experimental results highlighting their size-dependent magnetic response in water. This study has the potential to advance both the knowledge and practical utilization of Fe2O3 nanoclusters in various applications.

Citations

Citations to this article as recorded by  
  • Enzymatic properties of iron oxide nanoclusters and their application as a colorimetric glucose detection probe
    Dahyun Bae, Minhee Kim, Jin-sil Choi
    RSC Advances.2025; 15(6): 4573.     CrossRef
Article image
[Korean]
Exploration of Aluminum Alloy using Multi-feeder 3D Additive Manufacturing-based Combinatorial Experiment
Suwon Park, Yongwook Song, Jiyoon Yeo, Songyun Han, Hyunjoo Choi
J Powder Mater. 2023;30(3):255-261.   Published online June 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.3.255
  • 1,377 View
  • 8 Download
  • 3 Citations
AbstractAbstract PDF

Aluminum alloys are widely utilized in diverse industries, such as automobiles, aerospace, and architecture, owing to their high specific strength and resistance to oxidation. However, to meet the increasing demands of the industry, it is necessary to design new aluminum alloys with excellent properties. Thus, a new method is required to efficiently test additively manufactured aluminum alloys with various compositions within a short period during the alloy design process. In this study, a combinatory approach using a direct energy deposition system for metal 3D printing process with a dual feeder was employed. Two types of aluminum alloy powders, namely Al6061 and Al-12Cu, were utilized for the combinatory test conducted through 3D printing. Twelve types of Al-Si-Cu-Mg alloys were manufactured during this combinatory test, and the relationship between their microstructures and properties was investigated.

Citations

Citations to this article as recorded by  
  • Trends in Materials Modeling and Computation for Metal Additive Manufacturing
    Seoyeon Jeon, Hyunjoo Choi
    journal of Korean Powder Metallurgy Institute.2024; 31(3): 213.     CrossRef
  • Microstructural Effects on the Mechanical Properties of Ti-6Al-4V Fabricated by Direct Energy Deposition
    Juho Kim, Seoyeon Jeon, Hwajin Park, Taeyoel Kim, Hyunjoo Choi
    Journal of Powder Materials.2024; 31(4): 302.     CrossRef
  • Combinatorial Experiment for Al-6061 and Al-12Si alloy Based on Directed Energy Deposition (DED) Process
    Seoyeon Jeon, Suwon Park, Yongwook Song, Jiwon Park, Hyunyoung Park, Boram Lee, Hyunjoo Choi
    journal of Korean Powder Metallurgy Institute.2023; 30(6): 463.     CrossRef
Article image
[Korean]
Effect of WC Particle Size on the Microstructure, Mechanical and Electrical Properties of Ag/WC Sintered Electrical Contact Material
Soobin Kim, So-Yeon Park, Jong-Bin Lim, Soon Ho Kwon, Kee-Ahn Lee
J Powder Mater. 2023;30(3):242-248.   Published online June 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.3.242
  • 777 View
  • 3 Download
  • 1 Citations
AbstractAbstract PDF

The Ag/WC electrical contacts were prepared via powder metallurgy using 60 wt% Ag, 40 wt% WC, and small amounts of Co3O4 with varying WC particle sizes. After the fabrication of the contact materials, microstructure observations confirmed that WC-1 had an average grain size (AGS) of 0.27 μm, and WC-2 had an AGS of 0.35 μm. The Ag matrix in WC-1 formed fine grains, whereas a significantly larger and continuous growth of the Ag matrix was observed in WC-2. This indicates the different flow behaviors of liquid Ag during the sintering process owing to the different WC sizes. The electrical conductivities of WC-1 and WC-2 were 47.8% and 60.4%, respectively, and had a significant influence on the Ag matrix. In particular, WC-2 exhibited extremely high electrical conductivity owing to its large and continuous Ag-grain matrix. The yield strengths of WC-1 and WC-2 after compression tests were 349.9 MPa and 280.7 MPa, respectively. The high yield strength of WC-1 can be attributed to the Hall–Petch effect, whereas the low yield strength of WC-2 can be explained by the high fraction of high-angle boundaries (HAB) between the WC grains. Furthermore, the relationships between the microstructure, electrical/mechanical properties, and deformation mechanisms were evaluated.

Citations

Citations to this article as recorded by  
  • Enhanced Epoxy Composites Reinforced by 3D-Aligned Aluminum Borate Nanowhiskers
    Hyunseung Song, Kiho Song, Haejin Hwang, Changui Ahn
    Materials.2024; 17(19): 4727.     CrossRef
Article image
[Korean]
Analysis of the Effects of Process Variables and Alloy Composition on the Relative density and Mechanical Properties of 3D Printed Aluminum Alloys
Suwon Park, Jiyoon Yeo, Songyun Han, Hyunjoo Choi
J Powder Mater. 2023;30(3):223-232.   Published online June 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.3.223
  • 2,709 View
  • 14 Download
  • 1 Citations
AbstractAbstract PDF

Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.

Citations

Citations to this article as recorded by  
  • Effect of Heat Treatment on Microstructure and Mechanical Properties of Al–Zn–Mg–Cu–Si Sintered Alloys with and Without High-energy Ball Milling
    Junho Lee, Seonghyun Park, Sang-Hwa Lee, Seung Bae Son, Seok-Jae Lee, Jae-Gil Jung
    journal of Korean Powder Metallurgy Institute.2023; 30(6): 470.     CrossRef
Article image
[Korean]
Machine Learning-based Data Analysis for Designing High-strength Nb-based Superalloys
Eunho Ma, Suwon Park, Hyunjoo Choi, Byoungchul Hwang, Jongmin Byun
J Powder Mater. 2023;30(3):217-222.   Published online June 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.3.217
  • 728 View
  • 11 Download
AbstractAbstract PDF

Machine learning-based data analysis approaches have been employed to overcome the limitations in accurately analyzing data and to predict the results of the design of Nb-based superalloys. In this study, a database containing the composition of the alloying elements and their room-temperature tensile strengths was prepared based on a previous study. After computing the correlation between the tensile strength at room temperature and the composition, a material science analysis was conducted on the elements with high correlation coefficients. These alloying elements were found to have a significant effect on the variation in the tensile strength of Nb-based alloys at room temperature. Through this process, a model was derived to predict the properties using four machine learning algorithms. The Bayesian ridge regression algorithm proved to be the optimal model when Y, Sc, W, Cr, Mo, Sn, and Ti were used as input features. This study demonstrates the successful application of machine learning techniques to effectively analyze data and predict outcomes, thereby providing valuable insights into the design of Nb-based superalloys.

Article image
[Korean]
Enhancement of Thermoelectric Performance in Spark Plasma Sintered p-Type Bi0.5Sb1.5Te3.0 Compound via Hot Isostatic Pressing (HIP) Induced Reduction of Lattice Thermal Conductivity
Soo-Ho Jung, Ye Jin Woo, Kyung Tae Kim, Seungki Jo
J Powder Mater. 2023;30(2):123-129.   Published online April 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.2.123
  • 1,392 View
  • 8 Download
  • 4 Citations
AbstractAbstract PDF

High-temperature and high-pressure post-processing applied to sintered thermoelectric materials can create nanoscale defects, thereby enhancing their thermoelectric performance. Here, we investigate the effect of hot isostatic pressing (HIP) as a post-processing treatment on the thermoelectric properties of p-type Bi0.5Sb1.5Te3.0 compounds sintered via spark plasma sintering. The sample post-processed via HIP maintains its electronic transport properties despite the reduced microstructural texturing. Moreover, lattice thermal conductivity is significantly reduced owing to activated phonon scattering, which can be attributed to the nanoscale defects created during HIP, resulting in an ~18% increase in peak zT value, which reaches ~1.43 at 100°C. This study validates that HIP enhances the thermoelectric performance by controlling the thermal transport without having any detrimental effects on the electronic transport properties of thermoelectric materials.

Citations

Citations to this article as recorded by  
  • Enhanced Electrical Properties of 3D Printed Bi2Te3-Based Thermoelectric Materials via Hot Isostatic Pressing
    Seungki Jo
    Ceramist.2025; 28(1): 126.     CrossRef
  • Exploring Thermoelectric Transport Properties and Band Parameters of n-Type Bi2-xSbxTe3 Compounds Using the Single Parabolic Band Model
    Linh Ba Vu, Soo-ho Jung, Jinhee Bae, Jong Min Park, Kyung Tae Kim, Injoon Son, Seungki Jo
    journal of Korean Powder Metallurgy Institute.2024; 31(2): 119.     CrossRef
  • Investigation of the Thermal-to-Electrical Properties of Transition Metal-Sb Alloys Synthesized for Thermoelectric Applications
    Jong Min Park, Seungki Jo, Sooho Jung, Jinhee Bae, Linh Ba Vu, Kwi-Il Park, Kyung Tae Kim
    journal of Korean Powder Metallurgy Institute.2024; 31(3): 236.     CrossRef
  • Enhancing Electrical Properties of N-type Bismuth Telluride Alloys through Graphene Oxide Incorporation in Extrusion 3D Printing
    Jinhee Bae, Seungki Jo, Kyung Tae Kim
    journal of Korean Powder Metallurgy Institute.2023; 30(4): 318.     CrossRef
Article image
[Korean]
A Study on the Microstructures and Ionic Conductivity of Li1.3Al0.3Ti1.7(PO4)3 with Different Synthesis Routes
Seul Ki Choi, Jeawon Choi, MinHo Yang
J Powder Mater. 2023;30(2):107-115.   Published online April 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.2.107
  • 1,829 View
  • 39 Download
  • 1 Citations
AbstractAbstract PDF

Li1.3Al0.3Ti1.7(PO4)3(LATP) is considered a promising material for all-solid-state lithium batteries owing to its high moisture stability, wide potential window (~6 V), and relatively high ion conductivity (10-3–10-4 S/cm). Solid electrolytes based on LATP are manufactured via sintering, using LATP powder as the starting material. The properties of the starting materials depend on the synthesis conditions, which affect the microstructure and ionic conductivity of the solid electrolytes. In this study, we synthesize the LATP powder using sol-gel and co-precipitation methods and characterize the physical properties of powder, such as size, shape, and crystallinity. In addition, we have prepared a disc-shaped LATP solid electrolyte using LATP powder as the starting material. In addition, X-ray diffraction, scanning electron microscopy, and electrochemical impedance spectroscopic measurements are conducted to analyze the grain size, microstructures, and ion conduction properties. These results indicate that the synthesis conditions of the powder are a crucial factor in creating microstructures and affecting the conduction properties of lithium ions in solid electrolytes.

Citations

Citations to this article as recorded by  
  • Controlling the All-Solid Surface Reaction Between an Li1.3Al0.3Ti1.7(PO4)3 Electrolyte and Anode Through the Insertion of Ag and Al2O3 Nano-Interfacial Layers
    Gwanhee Song, Bojoong Kim, Inkook Hwang, Jiwon Kim, Jinmo Kim, Chang-Bun Yoon
    Materials.2025; 18(3): 609.     CrossRef
Article image
[English]
Study on Reaction Behavior of Mg-FeB Phase for Rare Earth Elements Recovery from End-of-life Magnet
Sangmin Park, Dae-Kyeom Kim, Rongyu Liu, Jaeyun Jeong, Taek-Soo Kim, Myungsuk Song
J Powder Mater. 2023;30(2):101-106.   Published online April 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.2.101
  • 855 View
  • 4 Download
AbstractAbstract PDF

Liquid metal extraction (LME), a pyrometallurgical recycling method, is popular owing to its negligible environmental impact. LME mainly targets rare-earth permanent magnets having several rare-earth elements. Mg is used as a solvent metal for LME because of its selective and eminent reactivity with rare-earth elements in magnets. Several studies concerning the formation of Dy-Fe intermetallic compounds and their effects on LME using Mg exist. However, methods for reducing these compounds are unavailable. Fe reacts more strongly with B than with Dy; B addition can be a reducing method for Dy-Fe intermetallic compounds owing to the formation of Fe2B, which takes Fe from Dy-Fe intermetallic compounds. The FeB alloy is an adequate additive for the decomposition of Fe2B. To accomplish the former process, Mg must convey B to a permanent magnet during the decomposition of the FeB alloy. Here, the effect of Mg on the transfer of B from FeB to permanent magnet is observed through microstructural and phase analyses. Through microstructural and phase analysis, it is confirmed that FeB is converted to Fe2B upon B transfer, owing to Mg. Finally, the transfer effect of Mg is confirmed, and the possibility of reducing Dy-Fe intermetallic compounds during LME is suggested.

Article image
[English]
Selective Laser Sintering of Co-Cr Alloy Powders and Sintered Products Properties
Dong-Wan Lee, Minh-Thuyet Nguyen, Jin-Chun Kim
J Powder Mater. 2023;30(1):7-12.   Published online February 1, 2023
DOI: https://doi.org/10.4150/KPMI.2023.30.1.7
  • 1,094 View
  • 19 Download
AbstractAbstract PDF

Metal-additive manufacturing techniques, such as selective laser sintering (SLS), are increasingly utilized for new biomaterials, such as cobalt-chrome (Co-Cr). In this study, Co-Cr gas-atomized powders are used as charge materials for the SLS process. The aim is to understand the consolidation of Co-Cr alloy powder and characterization of samples sintered using SLS under various conditions. The results clearly suggest that besides the matrix phase, the second phase, which is attributed to pores and oxidation particles, is observed in the sintered specimens. The as-built samples exhibit completely different microstructural features compared with the casting or wrought products reported in the literature. The microstructure reveals melt pools, which represent the characteristics of the scanning direction, in particular, or of the SLS conditions, in general. It also exposes extremely fine grain sizes inside the melt pools, resulting in an enhancement in the hardness of the as-built products. Thus, the hardness values of the samples prepared by SLS under all parameter conditions used in this study are evidently higher than those of the casting products.

Article image
[Korean]
Experimental Study on Improving Thermal Shock Resistance of Cement Composite Incorporating Hollow Glass Microspheres
Yomin Choi, Hyun‐Gyoo Shin
J Powder Mater. 2022;29(6):505-510.   Published online December 1, 2022
DOI: https://doi.org/10.4150/KPMI.2022.29.6.505
  • 605 View
  • 2 Download
AbstractAbstract PDF

The thermal shock resistance of cement composites with hollow glass microspheres (HGM) is investigated. Cement composites containing various concentrations of HGM are prepared and their properties studied. The density, thermal conductivity, and coefficient of thermal expansion of the composites decrease with increasing HGM concentration. A thermal shock test is performed by cycling between -60 and 50ºC. After the thermal shock test, the compressive strength of the cement composite without HGM decreases by 28.4%, whereas the compressive strength of the cement composite with 30 wt% HGM decreases by 5.7%. This confirms that the thermal shock resistance of cement is improved by the incorporation of HGM. This effect is attributed to the reduction of the thermal conductivity and coefficient of thermal expansion of the cement composite because of the incorporation of HGM, thereby reducing the occurrence of defects due to external temperature changes.

Article image
[Korean]
Comparison of Properties with Different Sintering Process of 3Y-TZP/WC Composites
Min-Soo Nam, Jae-Hyung Choi, Sahn Nahm, Seongwon Kim
J Powder Mater. 2022;29(5):424-431.   Published online October 1, 2022
DOI: https://doi.org/10.4150/KPMI.2022.29.5.424
  • 762 View
  • 3 Download
  • 1 Citations
AbstractAbstract PDF

3Y-TZP ceramics obtained by doping 3 mol.% of Y2O3 to ZrO2 to stabilize the phase transition are widely used in the engineering ceramic industry due to their excellent mechanical properties such as high strength, fracture toughness, and wear resistance. An additional increase in mechanical properties is possible by manufacturing a composite in which a high-hardness material such as oxide or carbide is added to the 3Y-TZP matrix. In this study, composite powder was prepared by dispersing a designated percentage of WC in the 3Y-TZP matrix, and the results were compared after manufacturing the composite using the different processes of spark plasma sintering and HP. The difference between the densification behavior and porosity with the process mechanism was investigated. The correlation between the process conditions and phase formation was examined based on the crystalline phase formation behavior. Changes to the microstructure according to the process conditions were compared using field-emission scanning electron microscopy. The toughness-strengthening mechanism of the composite with densification and phase formation was also investigated.

Citations

Citations to this article as recorded by  
  • Phase Formation and Mechanical Property of YSZ‒30 vol.% WC Composite Ceramics Fabricated by Hot Pressing
    Jin-Kwon Kim, Jae-Hyeong Choi, Nahm Sahn, Sung-Soo Ryu, Seongwon Kim
    journal of Korean Powder Metallurgy Institute.2023; 30(5): 409.     CrossRef
Article image
[Korean]
Fabrication and Characterization of NiCo2O4/Ni Foam Electrode for Oxygen Evolution Reaction in Alkaline Water Splitting
Minsol Kwon, Jaeseong Go, Yesol Lee, Sungmin Lee, Jisu Yu, Hyowon Lee, Sung Ho Song, Dongju Lee
J Powder Mater. 2022;29(5):411-417.   Published online October 1, 2022
DOI: https://doi.org/10.4150/KPMI.2022.29.5.411
  • 880 View
  • 9 Download
AbstractAbstract PDF

Environmental issues such as global warming due to fossil fuel use are now major worldwide concerns, and interest in renewable and clean energy is growing. Of the various types of renewable energy, green hydrogen energy has recently attracted attention because of its eco-friendly and high-energy density. Electrochemical water splitting is considered a pollution-free means of producing clean hydrogen and oxygen and in large quantities. The development of non-noble electrocatalysts with low cost and high performance in water splitting has also attracted considerable attention. In this study, we successfully synthesized a NiCo2O4/NF electrode for an oxygen evolution reaction in alkaline water splitting using a hydrothermal method, which was followed by post-heat treatment. The effects of heat treatment on the electrochemical performance of the electrodes were evaluated under different heat-treatment conditions. The optimized NCO/NF-300 electrode showed an overpotential of 416 mV at a high current density of 50 mA/cm2 and a low Tafel slope (49.06 mV dec-1). It also showed excellent stability (due to the large surface area) and the lowest charge transfer resistance (12.59 Ω). The results suggested that our noble-metal free electrodes have great potential for use in developing alkaline electrolysis systems.

Article image
[Korean]
Effect of Iron Content on Microstructure and Mechanical Properties of Ti-Mo-Fe P/M Alloys
HyoWoon Hwang, YongJae Lee, JiHwan Park, Dong-Geun Lee
J Powder Mater. 2022;29(4):325-331.   Published online August 1, 2022
DOI: https://doi.org/10.4150/KPMI.2022.29.4.325
  • 987 View
  • 6 Download
  • 2 Citations
AbstractAbstract PDF

Beta-titanium alloys are used in many industries due to their increased elongation resulting from their BCC structure and low modulus of elasticity. However, there are many limitations to their use due to the high cost of betastabilizer elements. In this study, biocompatible Ti-Mo-Fe beta titanium alloys are designed by replacing costly betastabilizer elements (e.g., Nb, Zr, or Ta) with inexpensive Mo and Fe elements. Additionally, Ti-Mo-Fe alloys designed with different Fe contents are fabricated using powder metallurgy. Fe is a strong, biocompatible beta-stabilizer element and a low-cost alloying element. The mechanical properties of the Ti-Mo-Fe metastable beta titanium alloys are analyzed in relation to the microstructural changes. When the Fe content increases, the tensile strength and elongation decrease due to brittle fracture despite a decreasing pore fraction. It is confirmed that the hardness and tensile strength of Ti-5Mo-2Fe P/M improve to more than 360 Hv and 900 MPa, respectively.

Citations

Citations to this article as recorded by  
  • Fabrication of Ti-Mo Core-shell Powder and Sintering Properties for Application as a Sputtering Target
    Won Hee Lee, Chun Woong Park, Heeyeon Kim, Yuncheol Ha, Jongmin Byun, Young Do Kim
    journal of Korean Powder Metallurgy Institute.2024; 31(1): 43.     CrossRef
  • Effect of Strain Rate on Deformation Behaviors of Ti-12.1Mo -1Fe Metastable Beta Alloy
    In Kyeong Jin, Dong-Geun Lee
    Korean Journal of Metals and Materials.2023; 61(10): 741.     CrossRef

Journal of Powder Materials : Journal of Powder Materials
TOP