Journal of Powder Materials

[Korean]
The Manufacturing Process of Clean Ni-Cr-Co-Based Superalloy Powder Using a Plasma Rotating Electrode: Kyu-Sik Kim, Dae Woong Kim, Yeontae Kim, Jung Hyo Park; J Powder Mater. 2025;32(3):222-231. Published online June 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00171

77 View
5 Download

Abstract PDF: Ni-based superalloys are widely used for critical components in aerospace, defense, industrial power generation systems, and other applications. Clean superalloy powders and manufacturing processes, such as compaction and hot isostatic pressing, are essential for producing superalloy discs used in turbine engines, which operate under cyclic rotating loads and high-temperature conditions. In this study, the plasma rotating electrode process (PREP), one of the most promising methods for producing clean metallic powders, is employed to fabricate Ni-based superalloy powders. PREP leads to a larger powder size and narrower distribution compared to powders produced by vacuum induction melt gas atomization. An important finding is that highly spheroidized powders almost free of satellites, fractured, and deformed particles can be obtained by PREP, with significantly low oxygen content (approximately 50 ppm). Additionally, large grain size and surface inclusions should be further controlled during the PREP process to produce high-quality powder metallurgy parts.

[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

79 View
8 Download

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

74 View
7 Download

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]
Thermodynamic and Electronic Descriptor-Driven Machine Learning for Phase Prediction in High-Entropy Alloys: Experimental Validation: Nguyen Lam Khoa, Nguyen Duy Khanh, Hoang Thi Ngoc Quyen, Nguyen Thi Hoang Oanh, , Le Hong Thang, Nguyen Hoa Khiem, Nguyen Hoang Viet; J Powder Mater. 2025;32(3):191-201. Published online June 30, 2025; DOI: https://doi.org/10.4150/jpm.2025.00143

133 View
7 Download

Abstract PDF: High-entropy alloys (HEAs) exhibit complex phase formation behavior, challenging conventional predictive methods. This study presents a machine learning (ML) framework for phase prediction in HEAs, using a curated dataset of 648 experimentally characterized compositions and features derived from thermodynamic and electronic descriptors. Three classifiers—random forest, gradient boosting, and CatBoost—were trained and validated through cross-validation and testing. Gradient boosting achieved the highest accuracy, and valence electron concentration (VEC), atomic size mismatch (δ), and enthalpy of mixing (ΔHmix) were identified as the most influential features. The model predictions were experimentally verified using a non-equiatomic Al₃₀Cu₁₇.₅Fe₁₇.₅Cr₁₇.₅Mn₁₇.₅ alloy and the equiatomic Cantor alloy (CoCrFeMnNi), both of which showed strong agreement with predicted phase structures. The results demonstrate that combining physically informed feature engineering with ML enables accurate and generalizable phase prediction, supporting accelerated HEA design.

[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

278 View
6 Download

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.

[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

192 View
2 Download

Abstract 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.

[English]
A Review of Recent Developments in CoCrFeMnNi High-Entropy Alloys Processed by Powder Metallurgy: Cheenepalli Nagarjuna, Sheetal Kumar Dewangan, Hansung Lee, Eunhyo Song, K. Raja Rao, Byungmin Ahn; J Powder Mater. 2025;32(2):145-164. Published online April 30, 2025; DOI: https://doi.org/10.4150/jpm.2024.00430

508 View
32 Download
1 Citations

Abstract PDF

In recent years, high-entropy alloys (HEAs) have attracted considerable attention in materials engineering due to their unique phase stability and mechanical properties compared to conventional alloys. Since the inception of HEAs, CoCrFeMnNi alloys have been widely investigated due to their outstanding strength and fracture toughness at cryogenic temperatures. However, their lower yield strength at room temperature limits their structural applications. The mechanical properties of HEAs are greatly influenced by their processing methods and microstructural features. Unlike traditional melting techniques, powder metallurgy (PM) provides a unique opportunity to produce HEAs with nanocrystalline structures and uniform compositions. The current review explores recent advances in optimizing the microstructural characteristics in CoCrFeMnNi HEAs by using PM techniques to improve mechanical performance. The most promising strategies include grain refinement, dispersion strengthening, and the development of heterogeneous microstructures (e.g., harmonic, bimodal, and multi-metal lamellar structures). Thermomechanical treatments along with additive manufacturing techniques are also summarized. Additionally, the review addresses current challenges and suggests future research directions for designing advanced HEAs through PM techniques.

Citations

Citations to this article as recorded by

Thermodynamic and Electronic Descriptor-Driven Machine Learning for Phase Prediction in High-Entropy Alloys: Experimental Validation
Nguyen Lam Khoa, Nguyen Duy Khanh, Hoang Thi Ngoc Quyen, Nguyen Thi Hoang, Oanh, Le Hong Thang, Nguyen Hoa Khiem, Nguyen Hoang Viet
Journal of Powder Materials.2025; 32(3): 191. CrossRef

[Korean]
Effect of Hatch Spacing on the Microstructure and Mechanical Properties of SA508 Gr.3 Steel Fabricated by Laser Powder Bed Fusion: Yuanjiu Huang, Ho Jin Ryu, Kee-Ahn Lee; J Powder Mater. 2025;32(1):50-58. Published online February 28, 2025; DOI: https://doi.org/10.4150/jpm.2024.00479

361 View
12 Download
1 Citations

Abstract PDF

This study investigated the effect of the hatch spacing parameter on the microstructure and mechanical properties of SA508 Gr.3 steel manufactured by laser powder bed fusion (L-PBF) for a nuclear pressure vessel. Materials were prepared with varying hatch spacing (0.04 mm [H4] and 0.06 mm [H6]). The H4 exhibited finer and more uniformly distributed grains, while the H6 showed less porosity and a lower defect fraction. The yield strength of the H4 material was higher than that of the H6 material, but there was a smaller difference between the materials in tensile strength. The measured elongation was 5.65% for the H4 material and 10.41% for the H6 material, showing a significantly higher value for H6. An explanation for this is that although the H4 material had a microstructure of small and uniform grains, it contained larger and more numerous pore defects than the H6 material, facilitating stress concentration and the initiation of microcracks.

Citations

Citations to this article as recorded by

Extremely low temperature mechanical behavior of in-situ oxide containing 304L stainless steel fabricated by laser powder bed fusion
Kwangtae Son, Seung-Min Jeon, Brian K. Paul, Young-Sang Na, Kijoon Lee, Young-Kyun Kim
Journal of Materials Science & Technology.2025; 234: 319. CrossRef

[English]
Effect of the Cross-rolling Process on the Microstructures and Mechanical Properties of 9Cr-1W ODS Steel: Bu-An Kim, Sanghoon Noh; J Powder Mater. 2025;32(1):37-42. Published online February 28, 2025; DOI: https://doi.org/10.4150/jpm.2024.00332

329 View
13 Download

Abstract PDF: This study employed a cross-rolling process to fabricate oxide dispersion strengthened (ODS) steel plates and investigated their microstructures and mechanical properties. The 9Cr-1W ODS ferritic steel was fabricated using mechanical alloying and hot isostatic pressing. The hot cross-rolling process produced thick ODS ferritic steel plates with a well-extended rectangular shape. The working direction greatly affected the grain structure and crystal texture of the ODS ferritic steel. Cross-rolled plates showed fine micro-grains with random crystal orientation, while unidirectionally rolled plates exhibited a strong orientation with larger, elongated grains. Transmission electron microscopy revealed a uniform distribution of nano-oxide particles in both rolling methods, with no major differences. Tensile tests of the ODS ferritic steel plates showed that the unidirectional rolled plates had anisotropic elongation, while cross-rolled plates exhibited isotropic behavior with uniform elongation. Cross-rolling produced finer, more uniform grains, reducing anisotropy and improving mechanical properties, making it ideal for manufacturing wide ODS steel components.

[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

700 View
27 Download

Abstract 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.

[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

346 View
9 Download

Abstract 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.

[Korean]
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; J Powder Mater. 2024;31(5):414-421. Published online October 31, 2024; DOI: https://doi.org/10.4150/jpm.2024.00311

417 View
14 Download

Abstract PDF: Friction welding, which uses heat and plastic flow to join metals, is expanding across industries due to its ability to weld heterogeneous alloys and simple process. However, process research is essential for materials with complex geometries, and limited research has been conducted on friction welding between cast and sintered metals. This study analyzed the mechanical properties and microstructural evolution of the joint by controlling the rotational speed and friction pressure, which affect the removal of the heat-affected zone in friction welding of casted SCM440 and sintered F-05-140. Hardness mapping and microstructure observations with material transition were performed to investigate the correlation between phase behavior and welding conditions. These results are anticipated to reduce costs and improve the mechanical properties of key mobility components.

[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

474 View
16 Download

Abstract 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.

[English]
Comparative Review of the Microstructural and Mechanical Properties of Ti-6Al-4V Fabricated via Wrought and Powder Metallurgy Processes: Raj Narayan Hajra, Gargi Roy, An Seong Min, Hyunseok Lee, Jeoung Han Kim; J Powder Mater. 2024;31(5):365-373. Published online October 31, 2024; DOI: https://doi.org/10.4150/jpm.2024.00213

723 View
35 Download
2 Citations

Abstract PDF

This review examines the microstructural and mechanical properties of a Ti-6Al-4V alloy produced by wrought processing and powder metallurgy (PM), specifically laser powder bed fusion (LPBF) and hot isostatic pressing. Wrought methods, such as forging and rolling, create equiaxed alpha (α) and beta (β) grain structures with balanced properties, which are ideal for fatigue resistance. In contrast, PM methods, particularly LPBF, often yield a martensitic α′ structure with high microhardness, enabling complex geometries but requiring post-processing to improve its properties and reduce stress. The study evaluated the effects of processing parameters on grain size, phase distribution, and material characteristics, guiding the choice of fabrication techniques for optimizing Ti-6Al-4V performance in aerospace, biomedical, and automotive applications. The analysis emphasizes tailored processing to meet advanced engineering demands.

Citations

Citations to this article as recorded by

Removal of Organic and Inorganic Contaminants from Titanium Turning Scrap via Alkali and Acid Two-Step Cleaning
Seong Min An, Raj Narayan Hajra, Chan Hee Park, Jin-Ho Yoon, Jinsung Rho, Chang-Min Yoon, Jeoung Han Kim
MATERIALS TRANSACTIONS.2025; 66(7): 855. CrossRef
Effect of oxygen content in feedstock powders on microstructure and mechanical properties of ELI Ti-6Al-4V fabricated via laser powder bed fusion
Woo Hyeok Kim, Sang Woo Kim, Raj Narayan Hajra, Gargi Roy, Jeoung Han Kim
Powder Metallurgy.2025;[Epub] CrossRef

[English]
Recovery of Barium, Nickel, and Titanium Powders from Waste MLCC: Haein Shin, Kun-Jae Lee; J Powder Mater. 2024;31(5):374-381. Published online October 31, 2024; DOI: https://doi.org/10.4150/jpm.2024.00192

732 View
27 Download

Abstract PDF: The development of the electronics industry has led to an increased demand for the manufacture of MLCC (Multilayer Ceramic Capacitors), which in turn is expected to result in a rise in MLCC waste. The MLCC contains various metals, notably barium, titanium, and nickel, whose disposal is anticipated to increase correspondingly. Recently, recycling technologies for electronic waste have garnered attention as they address waste management and raw material supply challenges. This paper investigates the recovery of barium, nickel, and titanium from the MLCC by a hydrometallurgical process. Using citric acid, which is an organic acid, the metal inside the MLCC was leached. Additionally, metal materials were recovered through precipitation and complexing processes. As a result, barium and titanium were recovered from the leachate of the waste MLCC, and 93% of the nickel-based powder was recovered. Furthermore, the optimal recovery process conditions for recycling these metal elements were investigated.

Search