- Densification of Copper Powders using High-pressure Torsion Process
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Dong-Jun Lee, Eun-Yoo Yoon, Soo-Young Kang, Jung-Hwan Lee, Hyoung-Seop Kim
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J Korean Powder Metall Inst. 2012;19(5):333-337.
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DOI: https://doi.org/10.4150/KPMI.2012.19.5.333
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- In this study, electrolytic copper powders were consolidated by high-pressure torsion process (HPT) which is the most effective process to produce bulk ultrafine grained and nanocrystalline metallic materials among various severe plastic deformation processes. The bulk samples were manufactured by the HPT process at 2.5 GPa and 1/2, 1 and 10 turns. After 10 turns, full densification was achieved by high pressure with shear deformation and ultrafine grained structure (average grain size of 677 nm) was observed by electron backscatter diffraction and a scanning transmission electron microscope.
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- Analyses of Densification and Consolidation of Copper Powders during High-Pressure Torsion Process Using Finite Element Method
Dong Jun Lee, Eun Yoo Yoon Journal of Korean Powder Metallurgy Institute.2015; 22(1): 6. CrossRef - Microstructure Evolution and Mechanical Properties of Al-1080 Processed by a Combination of Equal Channel Angular Pressing and High Pressure Torsion
Mohamed Ibrahim Abd El Aal, Eun Yoo Yoon, Hyoung Seop Kim Metallurgical and Materials Transactions A.2013; 44(6): 2581. CrossRef
- Ultrafine Grained Cu-diamond Composites using High Pressure Torsion
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Eun-Yoo Yoon, Dong-Jun Lee, Taek-Soo Kim, Hyoung-Seop Kim
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J Korean Powder Metall Inst. 2012;19(3):204-209.
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DOI: https://doi.org/10.4150/KPMI.2012.19.3.204
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- In this work, powder metallurgy and severe plastic deformation by high-pressure torsion (HPT) approaches were combined to achieve both full density and grain refinement at the same time. Pure Cu powders were mixed with 5 and 10 vol% diamonds and consolidated into disc-shaped samples at room temperature by HPT at 1.25 GPa and 1 turn, resulting in ultrafine grained metallic matrices embedded with diamonds. Neither heating nor additional sintering was required with the HPT process so that in situ consolidation was successfully achieved at ambient temperature. Significantly refined grain structures of Cu metallic matrices with increasing diamond volume fractions were observed by electron backscatter diffraction (EBSD), which enhanced the microhardness of the Cu-diamond composites.
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- Effect of a nano-sized TiC particle addition on the flow-assisted corrosion resistance of SA 106B carbon steel
Jin-Ju Park, Eun-Kwang Park, Gyoung-Ja Lee, Chang-Kyu Rhee, Min-Ku Lee Applied Surface Science.2017; 415: 143. CrossRef - Analyses of Densification and Consolidation of Copper Powders during High-Pressure Torsion Process Using Finite Element Method
Dong Jun Lee, Eun Yoo Yoon Journal of Korean Powder Metallurgy Institute.2015; 22(1): 6. CrossRef - Trend in Research of Powder Consolidation Using Severe Plastic Deformation
Eun Yoo Yoon, Dong Jun Lee, Dong-Hyun Ahn, Hyuk Jae Jeong, Hyoung Seop Kim Journal of Korean Powder Metallurgy Institute.2013; 20(2): 148. CrossRef - Microstructure Evolution and Mechanical Properties of Al-1080 Processed by a Combination of Equal Channel Angular Pressing and High Pressure Torsion
Mohamed Ibrahim Abd El Aal, Eun Yoo Yoon, Hyoung Seop Kim Metallurgical and Materials Transactions A.2013; 44(6): 2581. CrossRef - Grinding Behaviour of Aluminum Powder for Al/CNTs Nano Composites Fabrication by Dry Grinding Process Using a High Speed Planetary Ball Mill
Heekyu Choi, Jehyun Lee, Seongsoo Kim, Gyungpil Choi, Daehyung Bae, Sungbak Lee, Woong Lee Korean Journal of Materials Research.2013; 23(2): 89. CrossRef - Densification of Copper Powders using High-pressure Torsion Process
Dong-Jun Lee, Eun-Yoo Yoon, Soo-Young Kang, Jung-Hwan Lee, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2012; 19(5): 333. CrossRef
- Densification and Nanocrystallization of Water-Atomized Pure Iron Powder Using High Pressure Torsion
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Eun-Yoo Yoon, Dong-Jun Lee, Ha-Neul Kim, Hee-Soo Kang, Eon-Sik Lee, Hyoung-Seop Kim
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J Korean Powder Metall Inst. 2011;18(5):411-416.
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DOI: https://doi.org/10.4150/KPMI.2011.18.5.411
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172
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- In this study, powder metallurgy and severe plastic deformation by high-pressure torsion (HPT) approaches were combined to achieve both full density and grain refinement at the same time. Water-atomized pure iron powders were consolidated to disc-shaped samples at room temperature using HPT of 10 GPa up to 3 turns. The resulting microstructural size decreases with increasing strain and reaches a steady-state with nanocrystalline (down to ~250 nm in average grain size) structure. The water-atomized iron powders were deformed plastically as well as fully densified, as high as 99% of relative density by high pressure, resulting in effective grain size refinements and enhanced microhardness values.
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- Analyses of Densification and Consolidation of Copper Powders during High-Pressure Torsion Process Using Finite Element Method
Dong Jun Lee, Eun Yoo Yoon Journal of Korean Powder Metallurgy Institute.2015; 22(1): 6. CrossRef - Microstructure Evolution and Mechanical Properties of Al-1080 Processed by a Combination of Equal Channel Angular Pressing and High Pressure Torsion
Mohamed Ibrahim Abd El Aal, Eun Yoo Yoon, Hyoung Seop Kim Metallurgical and Materials Transactions A.2013; 44(6): 2581. CrossRef - Trend in Research of Powder Consolidation Using Severe Plastic Deformation
Eun Yoo Yoon, Dong Jun Lee, Dong-Hyun Ahn, Hyuk Jae Jeong, Hyoung Seop Kim Journal of Korean Powder Metallurgy Institute.2013; 20(2): 148. CrossRef - Ultrafine Grained Cu-diamond Composites using High Pressure Torsion
Eun-Yoo Yoon, Dong-Jun Lee, Taek-Soo Kim, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2012; 19(3): 204. CrossRef - Densification of Copper Powders using High-pressure Torsion Process
Dong-Jun Lee, Eun-Yoo Yoon, Soo-Young Kang, Jung-Hwan Lee, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2012; 19(5): 333. CrossRef
- Quantitative Analysis of Roughness of Powder Surface Using Three-Dimensional Laser Profiler and its Effect on Green Strength of Powder Compacts
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Dong-Jun Lee, Eun-Yoo Yoon, Ha-Neul Kim, Hee-Soo Kang, Eon-Sik Lee, Hyoung-Seop Kim
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J Korean Powder Metall Inst. 2011;18(5):406-410.
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DOI: https://doi.org/10.4150/KPMI.2011.18.5.406
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197
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- Green strength is an important property of powders since high green strength guarantees easy and safe handling before sintering. The green strength of a powder compact is related to mainly mechanical and surface characters, governed by interlocking of the particles. In this study, the effect of powder surface roughness on the green strength of iron powders was investigated using a transverse rupture test. Three-dimensional laser profiler was employed for quantitative analyses of the surface roughness. Two different surface conditions, i.e. surface roughness, of powders were compared. The powders having rough surfaces show higher green strength than the round surface powders since higher roughness leads increasing interlocked area between the contacting powders.
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- A Study on the Carbon Composite Briquette Iron Manufacturing Using Fe-containing Process Wastes
Jong Yeong Yu, Dae Young Yang, Hee Dong Shin, Il Sohn Journal of the Korean Institute of Resources Recycling.2015; 24(3): 34. CrossRef - Obtaining Mechanical Properties of Fe Powder Using a Combined Nanoindentation and the Finite Element Method
Hyeok Jae Jeong, Dong Jun Lee, Eun Yoo Yoon, Eon Sik Lee, Nack Joon Kim, Hyeong Seop Kim Journal of Korean Powder Metallurgy Institute.2013; 20(4): 280. CrossRef
- Effect of Particle Size on Compactibility of Water-atomized Pure Iron Powder
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Dong-Jun Lee, Eun-Yoo Yoon, Ha-Neul Kim, Hee-Soo Kang, Eon-Sik Lee, Hyoung-Seop Kim
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J Korean Powder Metall Inst. 2011;18(3):221-225.
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DOI: https://doi.org/10.4150/KPMI.2011.18.3.221
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187
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- In the current study, the effects of particle size on compaction behavior of water-atomized pure iron powders are investigated. The iron powders are assorted into three groups depending on the particle size; 20-45 µM, 75-106 µM, and 150-180 µM for the compaction experiments. The powder compaction procedures are processed with pressure of 200, 400, 600, and 800 MPa in a cylindrical die. After the compaction stage, the group having 150-180 µM of particle size distribution shows the best densification behavior and reaches the highest green density. The reason for these results can be explained by the largest average grain size in the largest particle group, due to the low plastic deformation resistance in large grain sized materials.
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- Preparation of high-purity reduced iron powder by Höganäs process from ultra-pure magnetite concentrate
Jin-tian Wu, Bin Xu, Zhong-lin Dong, Yu-juan Zhou, Liang-ping Xu, Guang-hui Li, Tao Jiang Journal of Central South University.2023; 30(9): 3006. CrossRef - Hydrogen Reduction Behavior of Oxide Scale in Water-atomized Iron Powder
Hea-Min Shin, Kyeong-Ho Baik Journal of Korean Powder Metallurgy Institute.2014; 21(6): 422. CrossRef - Quantitative Analysis of Roughness of Powder Surface Using Three-Dimensional Laser Profiler and its Effect on Green Strength of Powder Compacts
Dong-Jun Lee, Eun-Yoo Yoon, Ha-Neul Kim, Hee-Soo Kang, Eon-Sik Lee, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2011; 18(5): 406. CrossRef
- Consolidation and Mechanical Behavior of Gas Atomized MgZn4.3Y0.7 Alloy Powders using High Pressure Torsion
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Eun-Yoo Yoon, Hong-Jun Chae, Taek-Soo Kim, Chong-Soo Lee, Hyoung-Seop Kim
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J Korean Powder Metall Inst. 2010;17(3):190-196.
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DOI: https://doi.org/10.4150/KPMI.2010.17.3.190
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157
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- In this paper, rapid solidified Mg-4.3Zn-0.7Y (at.%) alloy powders were prepared using an inert gas atomizer, followed by a severe plastic deformation technique of high pressure torsion (HPT) for consolidation of the powders. The gas atomized powders were almost spherical in shape, and grain size was as fine as less than 5;µm due to rapid solidification. Plastic deformation responses during HPT were simulated using the finite element method, which shows in good agreement with the analytical solutions of a strain expression in torsion. Varying the HPT processing temperature from ambient to 473 K, the behavior of powder consolidation, matrix microstructural evolution and mechanical properties of the compacts was investigated. The gas atomized powders were deformed plastically as well as fully densified, resulting in effective grain size refinements and enhanced microhardness values.
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- Trend in Research of Powder Consolidation Using Severe Plastic Deformation
Eun Yoo Yoon, Dong Jun Lee, Dong-Hyun Ahn, Hyuk Jae Jeong, Hyoung Seop Kim Journal of Korean Powder Metallurgy Institute.2013; 20(2): 148. CrossRef - Densification of Copper Powders using High-pressure Torsion Process
Dong-Jun Lee, Eun-Yoo Yoon, Soo-Young Kang, Jung-Hwan Lee, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2012; 19(5): 333. CrossRef - Ultrafine Grained Cu-diamond Composites using High Pressure Torsion
Eun-Yoo Yoon, Dong-Jun Lee, Taek-Soo Kim, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2012; 19(3): 204. CrossRef - Densification and Nanocrystallization of Water-Atomized Pure Iron Powder Using High Pressure Torsion
Eun-Yoo Yoon, Dong-Jun Lee, Ha-Neul Kim, Hee-Soo Kang, Eon-Sik Lee, Hyoung-Seop Kim Journal of Korean Powder Metallurgy Institute.2011; 18(5): 411. CrossRef
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