Journal of Powder Materials

Volume 20(3); June 2013

[English]
Sintering of Nd-Fe-B Magnets from Dy Coated Powder: Jin Woo Kim, Young Do Kim; J Korean Powder Metall Inst. 2013;20(3):169-173.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.169

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High-coercive (Nd,Dy)-Fe-B magnets were fabricated via dysprosium coating on Nd-Fe-B powder. The sputtering coating process of Nd-Fe-B powder yielded samples with densities greater than 98%. (Nd,Dy)_2Fe_14B phases may have effectively penetrated into the boundaries between neighboring Nd_2Fe_14B grains during the sputtering coating process, thereby forming a (Nd,Dy)_2Fe_14B phase at the grain boundary. The maximum thickness of the Dy shell was approximately 70 nm. The maximum coercivity of the Dy sputter coated samples(sintered samples) increased from 1162.42 to 2020.70 kA/m. The microstructures of the (Nd,Dy)_2Fe_14B phases were effectively controlled, resulting in improved magnetic properties. The increase in coercivity of the Nd-Fe-B sintered magnet is discussed from a microstructural point of view.

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Recovery of Valuable Metals from Acoustic Magnet Swarf Slurry
Wei-Sheng Chen, Li-Pang Wang, Chen-Yao Hung, C.-H. Weng, R. Weerasinghe
E3S Web of Conferences.2018; 53: 04015. CrossRef

[Korean]
Study on the Reduction of Forging Oxide Scale using Hydrogen: Dong-Won Lee, Jung-Yeul Yun, Shun-Myung Shin, In-Soo Kim, Jei-Pil Wang; J Korean Powder Metall Inst. 2013;20(3):174-179.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.174

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The study on the fabrication of iron powder from forging scales using hydrogen gas has been conducted on the effect of hydrogen partial pressure, temperature, and reactive time. The mechanism for the reduction of iron oxides was proposed with various steps, and it was found that reduction pattern might be different depending on temperature. The iron content in the scale and reduction ratio of oxygen were both increased with increasing reactive time at 0.1atm of hydrogen partial pressure. On the other hand, for over 30 minutes at 0.5 atm of hydrogen partial pressure, the values were found to be almost same. In the long run, iron metallic powder was obtained with over 90% of iron content and an average size of its powder was observed to be about 100µm.

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Effects of expanded graphite content on the performance of MgO‐C refractories
Junseong Kim, Seunghwa Jeong, Minsuk Lee, Dong Jae Kang, Hong‐woo Park, Hwa‐In Lee, Dong‐Yeol Yang, Eun Hee Kim, Soonil Lee, Seung‐Cheol Yang, Sang‐Chae Jeon
International Journal of Applied Ceramic Technology.2023; 20(6): 3803. CrossRef
Smithing Processes Based on Hammer Scale Excavated from the Third- to Fourth-Century Ancient Iron-Making Sites of the Korean Peninsula
Dayeon Jung, Heehong Kwon, Namchul Cho
Materials.2022; 15(12): 4188. CrossRef

[English]
Synthesis, Characterization and Functionalization of the Coated Iron Oxide Nanostructures: Oybek Tursunkulov, Bunyod Allabergenov, Amir Abidov, Soon-Wook Jeong, Sungjin Kim; J Korean Powder Metall Inst. 2013;20(3):180-185.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.180

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The iron oxides nanoparticles and iron oxide with other compounds are of importance in fields including biomedicine, clinical and bio-sensing applications, corrosion resistance, and magnetic properties of materials, catalyst, and geochemical processes etc. In this work we describe the preparation and investigation of the properties of coated magnetic nanoparticles consisting of the iron oxide core and organic modification of the residue. These fine iron oxide nanoparticles were prepared in air environment by the co-precipitation method using of Fe2+: Fe3+ where chemical precipitation was achieved by adding ammonia aqueous solution with vigorous stirring. During the synthesis of nanoparticles with a narrow size distribution, the techniques of separation and powdering of nanoparticles into rather monodisperse fractions are observed. This is done using controlled precipitation of particles from surfactant stabilized solutions in the form organic components. It is desirable to maintain the particle size within pH range, temperature, solution ratio wherein the particle growth is held at a minimum. The iron oxide nanoparticles can be well dispersed in an aqueous solution were prepared by the mentioned co-precipitation method. Besides the iron oxide nanowires were prepared by using similar method. These iron oxide nanoparticles and nanowires have controlled average size and the obtained products were investigated by X-ray diffraction, FESEM and other methods.

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Diacerein-loaded surface modified iron oxide microparticles (SMIOMPs): an emerging magnetic system for management of osteoarthritis via intra-articular injection
Nouran Abdelmageed Ali, Nadia M. Morsi, Shaimaa M. Badr-Eldin, Rehab N. Shamma
Frontiers in Bioengineering and Biotechnology.2024;[Epub] CrossRef
Facile Fabrication of Flexible Electrodes and Immobilization of Silver Nanoparticles on Nanoscale Silicate Platelets to Form Highly Conductive Nanohybrid Films for Wearable Electronic Devices
Peng-Yang Huang, Chih-Wei Chiu, Chen-Yang Huang, Sheng-Yen Shen, Yen-Chen Lee, Chih-Chia Cheng, Ru-Jong Jeng, Jiang-Jen Lin
Nanomaterials.2019; 10(1): 65. CrossRef

[Korean]
Electrochemical Properties for the Corrosion of Zinc Anode with Different Particle Size and Shape in Zinc/air Batteries: Won-Geun Yang, Jung-Eui Hong, Rye-Gyeong Oh, Ji-Woo Oh, Young-Min Kong, Kwang-Sun Ryu; J Korean Powder Metall Inst. 2013;20(3):186-190.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.186

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The electrochemical performance for the corrosion of zinc anodes according to particle size and shape as anode in Zn/air batteries was study. We prepared five samples of Zn powder with different particle size and morphology. For analysis the particle size of theme, we measured particle size analysis (PSA). As the result, sample (e) had smaller particle size with 10.334µm than others. For measuring the electrochemical performance of them, we measured the cyclic voltammetry and linear polarization in three electrode system (half-cell). For measuring the morphology change of them before and after cyclic voltammetry, we measured Field Emission Scanning Electron Microscope (FE-SEM). From the cyclic voltammetry, as the zinc powder had small size, we knew that it had large diffusion coefficient. From the linear polarization, as the zinc powder had small size, it was a good state with high polarization resistance as anode in Zn/air batteries. From the SEM images, the particle size had increased due to the dendrite formation after cyclic voltammetry. Therefore, the sample (e) with small size would have the best electrochemical performance between these samples.

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Spheroidization of Pure-vanadium Powder using Radio Frequency Thermal Plasma Process
Nana Kwabena Adomako, Seungmin Yang, Min Gyu Lee, N. S. Reddy, Jeoung-Han Kim
Journal of Korean Powder Metallurgy Institute.2019; 26(4): 305. CrossRef
Effects of Powder Shape and Densification Mechanism on the Microstructures and Mechanical Properties of Ti-6Al-4V Components
Youngmoo Kim, Young-Sam Kwon, Young-Beom Song, Sung Ho Lee
Journal of Korean Powder Metallurgy Institute.2019; 26(4): 311. CrossRef

[Korean]
Optimization of Wet Reduction Processing for Nanosized Cobalt Powder: Hyun-Seon Hong, Hang-Chul Jung, Geon-Hong Kim, Lee-Seung Kang, Han-Gil Suk; J Korean Powder Metall Inst. 2013;20(3):191-196.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.191

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Nano-sized cobalt powder was fabricated by wet chemical reduction method at room temperature. The effects of various experimental variables on the overall properties of fabricated nano-sized cobalt powders have been investigated in detail, and amount of NaOH and reducing agent and dropping speed of reducing agent have been properly selected as experimental variables in the present research. Minitab program which could find optimized conditions was adopted as a statistic analysis. 3D Scatter-Plot and DOE (Design of Experiments) conditions for synthesis of nano-sized cobalt powder were well developed using Box-Behnken DOE method. Based on the results of the DOE process, reproducibility test were performed for nano-sized cobalt powder. Spherical nano-sized cobalt powders with an average size of 70-100 nm were successfully developed and crystalline peaks for the HCP and FCC structure were observed without second phase such as Co(OH)_2.

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Preparation of Spherical Cobalt Fine Powders by New Liquid Reduction Method
Dae Weon Kim, Ji-Hoon Kim, Yo-Han Choi, Hee Lack Choi, Jin-Ho Yoon
journal of Korean Powder Metallurgy Institute.1970; 22(4): 260. CrossRef

[Korean]
Preparation of Highly Efficient Nd-Fe-B Magnetic Powders by Reduction/Diffusion Process: Dongsoo Kim, Chunqiang Chen, Younkyoung Baek, Chuljin Choi; J Korean Powder Metall Inst. 2013;20(3):197-202.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.197

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Abstract PDF: A novel route to prepare Nd-Fe-B magnetic particles by utilizing both spray drying and reduction/diffusion processes was investigated in this study. Precursors were prepared by spray drying method using the aqueous solutions containing Nd salt, Fe salt and boric acid with stoichiometric ratios. Precursor particles could be obtained with various sizes from 2 to 10µm by controlling concentrations of the solutions and the average size of 2µm of precursors were selected for further steps. After heat treatment of precursors in air, Nd and Fe oxides were formed through desalting procedure, followed by reduction processes in Hydrogen (H_2) atmosphere and with Calcium (Ca) granules in Argon (Ar) successively. Moreover, diffusion between Nd and Fe occurred during Ca reduction and Nd_2Fe_14B particles were formed. With Ca amount added to particles after H_2 reduction, intrinsic coercivity was changed from 1 to 10 kOe. In order to remove and leach CaO and residual Ca, de-ionized water and dilute acid were used. Acidic solutions were more effective to eliminate impurities, but Fe and Nd were dissolved out from the particles. Finally, Nd_2Fe_14B magnetic particles were synthesized after washing in de-ionized water with a mean size of 2µm and their maximum energy product showed 9.23 MGOe.

[Korean]
The Effect of the Additive Elements Alloying Method on the Corrosion Resistance of Sintered STS 316L: Hye Seong Kim, Yoo Young Kim, Dong Kyu Park, In Shup Ahn; J Korean Powder Metall Inst. 2013;20(3):203-209.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.203

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Abstract PDF: In this study, STS 316L powders with 3 wt.% Cu and 1 wt.% Sn known as corrosion-resistance reinforcement elements, are prepared to make different kinds of specimens, in which, 3 wt.% Cu and 1 wt.% Sn are added in different forms by mixing, alloying and fully alloying. After sintering in the same condition, the corrosion resistance, wear resistance and their mechanical properties of specimens are tested respectively. According to the comparison, STS 316L specimen sintered at 1270°C showed the most excellent mechanical property: HRB 78 (hardness), 1130.7 MPa (RCS), 26.6% (Fraction Wear), It was similar with the specimen made of STS316L and fully alloyed Cu and Sn powders, meanwhile, the latter one appears the best corrosion resistance, 75hrs-salt immersion test results. In addition, the specimens with Cu and Sn powders additive showed relatively worse wear resistance in compared with STS316L specimen.

[Korean]
Color Evolution and Phase Transformation of α-FeOOH@SiO₂ and β-FeOOH@SiO₂ pigments: Ri Yu, Kyoon Choi, Jae-Hwan Pee, YooJin Kim; J Korean Powder Metall Inst. 2013;20(3):210-214.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.210

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This manuscript reports on compared color evolution about phase transformation of alpha-FeOOH@SiO_2 and beta-FeOOH@SiO_2 pigments. Prepared alpha-FeOOH and beta-FeOOH were coated with silica for enhancing thermal properties and coloration of both samples. To study phase and color of alpha-FeOOH and beta-FeOOH, we prepared nano sized iron oxide hydroxide pigments which were coated with SiO_2 using tetraethylorthosilicate and cetyltrimethyl-ammonium bromide as a surface modifier. The silica-coated both samples were calcined at high temperatures (300, 700 and 1000°C) and characterized by scanning electron microscopy, CIE L*a*b* color parameter measurements, transmission electron microscopy and UV-vis spectroscopy. The yellow alpha-FeOOH and beta-FeOOH was transformed to alpha-Fe_2O_3 with red, brown at 300, 700°C, respectively.

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Coloration and Chemical Stability of SiO2and SnO2Coated Blue CoAl2O4Pigment
JiYeon Yun, Ri Yu, Jae-Hwan Pee, YooJin Kim
Journal of Korean Powder Metallurgy Institute.2014; 21(5): 377. CrossRef

[Korean]
Effect of B₄C Content on the Sintering Characteristics of 6061Al-B₄C Composite Powder: Jin-Ju Park, Sung-Mo Hong, Kyoung-Yeol Kim, Min-Ku Lee, Chang-Kyu Rhee, Won-Hyuk Rhee, Yang Kyu Lee; J Korean Powder Metall Inst. 2013;20(3):215-220.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.215

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Abstract PDF: In the present work, 6061 Al-B_4C sintered composites containing different B_4C contents were fabricated and their characteristic were investigated as a function of sintering temperature. For this, composite powders and their compacts with B_4C various contents from 0 to 40 wt.% were fabricated using a planetary ball milling equipment and cold isostatic pressing, respectively, and then they were sintered in the temperature ranges of 580 to 660°C. Above sintering temperature of 640°C, real density was decreased due to the occurrence of sweat phenomena. In addition, it was realized that sinterability of 6061Al-B_4C composite material was lowered with increasing B_4C content, resulting in the decrease in its real density and at the same time in the increment of porosity.

[English]
Fabrication of Fe-TiB₂ Composite Powder by High-Energy Milling and Subsequent Reaction Synthesis: H.X. Khoa, N.Q. Tuan, Y.H. Lee, B.H. Lee, N.H. Viet, J.S. Kim; J Korean Powder Metall Inst. 2013;20(3):221-227.; DOI: https://doi.org/10.4150/KPMI.2013.20.3.221

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TiB_2-reinforced iron matrix composite (Fe-TiB_2) powder was in-situ fabricated from titanium hydride (TiH_2) and iron boride (FeB) powders by the mechanical activation and a subsequent reaction. Phase formation of the composite powder was identified by X-ray diffraction (XRD). The morphology and phase composition were observed and measured by field emission-scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. The results showed that TiB_2 particles formed in nanoscale were uniformly distributed in Fe matrix. Fe_2B phase existed due to an incomplete reaction of Ti and FeB. Effect of milling process and synthesis temperature on the formation of composite were discussed.

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Xueyin Liu, Quanli Jia, Shaowei Zhang, William E. Lee
International Materials Reviews.2024; 69(2): 107. CrossRef
TiB2-Fe hard alloys obtained using SHS powders of the Ti-B-Fe system
O.K. Lepakova, O.A. Shkoda
International Journal of Refractory Metals and Hard Materials.2024; 125: 106915. CrossRef
In Situ Spark Plasma Sintering, Microstructure and Mechanical Properties of Fe-15Cr-2Mn-1.5Al Matrix Composites Reinforced with TiB2 and CrFeB
Jian Liu, Min Wu, Bin Wang, Wei Xu, Weiping Chen, Fangfang Liu
JOM.2023; 75(3): 886. CrossRef
Glass-Forming Ability and Magnetic Properties of Al82Fe16Ce2 and Al82Fe14Mn2Ce2 Alloys Prepared by Mechanical Alloying
Nguyen Hong Hai, Nguyen Hoang Viet, Nguyen Thi Hoang Oanh
Applied Sciences.2023; 14(1): 152. CrossRef
Powder metallurgy processed TiB2-reinforced steel matrix composites: a review
Silani Sahoo, Bharat Bhushan Jha, Animesh Mandal
Materials Science and Technology.2021; 37(14): 1153. CrossRef
Synthesis of Cu-based TiCx composites via in-situ reaction between CuxTi melt and dissolvable solid carbon
Lei Guo, Yang Yang, Xiaochun Wen, Han Gao, Zhe Wang, Zhancheng Guo
Powder Technology.2020; 362: 375. CrossRef
Microstructure and Electrical Property of Ex-Situ and In-Situ Copper Titanium Carbide Nanocomposites
Nguyen Hoang Viet, Nguyen Thi Hoang Oanh
Metals.2020; 10(6): 735. CrossRef
Mechanical and Wear Behaviour of Hot-Pressed 304 stainless Steel Matrix Composites Containing TiB2 Particles
Silani Sahoo, Bharat B. Jha, Tarasankar Mahata, Jyothi Sharma, Tammana S. R. Ch. Murthy, Animesh Mandal
Transactions of the Indian Institute of Metals.2019; 72(5): 1153. CrossRef
Effect of volume fraction of reinforcement phase on mechanical behavior of ultra-high-temperature composite consisting of iron matrix and TiB2 particulates
Babak Jahani, Mehdi Salimi Jazi, Fardad Azarmi, Andrew Croll
Journal of Composite Materials.2018; 52(5): 609. CrossRef
Impression creep behaviour of TiB2 particles reinforced steel matrix composites
S. Sahoo, B. B. Jha, T.S. Mahata, J. Sharma, T. S. R. Ch. Murthy, A. Mandal
Materials Science and Technology.2018; 34(16): 1965. CrossRef

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