Journal of Powder Materials

Seong-Won Kim

8 Articles

Effect of the Size and Amount of SiC on the Microstructures and Thermal Conductivities of ZrB₂-SiC Composite Ceramics: Seong-Won Kim, Chang-Sup Kwon, Yoon-Suk Oh, Sung-Min Lee, Hyung-Tae Kim; J Korean Powder Metall Inst. 2012;19(5):379-384.; DOI: https://doi.org/10.4150/KPMI.2012.19.5.379

21 View
0 Download
3 Citations

This paper reports the microstructures and thermal conductivities of ZrB_2-SiC composite ceramics with size and amount of SiC. We fabricated sintered bodies of ZrB_2-x vol.% SiC (x=10, 20, 30) with submicron and nanosized SiC densified by spark plasma sintering. Microstructure retained the initial powder size of especially SiC, except the agglomeration of nanosized SiC. For sintered bodies, thermal conductivities were examined. The observed thermal conductivity values are 40~60 W/mK, which is slightly lower than the reported values. The relation between microstructural parameter and thermal conductivity was also discussed.

Citations

Citations to this article as recorded by

Analysis of Polymer Hybrid-coated Anodic Aluminum Oxide
Mira Kim, Yeongwoo Kim, Hakyoung Lee, Chan-Young Park, Won-Ki Lee, Taeho Kang, Kwon Taek Lim
Molecular Crystals and Liquid Crystals.2015; 622(1): 120. CrossRef
Thermal Properties of Diamond Aligned Electroless Ni Plating Layer/Oxygen Free Cu Substrates
Da-Woon Jeong, Song-Yi Kim, Kyoung-Tae Park, Seok-Jun Seo, Taek Soo Kim, Bum Sung Kim
Journal of Korean Powder Metallurgy Institute.2015; 22(2): 134. CrossRef
Effect of the SiC Size on the Thermal and Mechanical Properties of Reaction-bonded Silicon Carbide Ceramics
Chang-Sup Kwon, Yoon-Suk Oh, Sung-Min Lee, Yoonsoo Han, Hyun-Ick Shin, Youngseok Kim, Seongwon Kim
Journal of Korean Powder Metallurgy Institute.2014; 21(6): 467. CrossRef

The Effect of Sintering Processes and Additives on the Microstructures and Mechanical Properties of ZrB₂-SiC Composite Ceramics: Chang-Sup Kwon, Jung-Min Chae, Hyung-Tae Kim, Kyung-Ja Kim, Seong-Won Kim; J Korean Powder Metall Inst. 2011;18(6):562-567.; DOI: https://doi.org/10.4150/KPMI.2011.18.6.562

24 View
0 Download
1 Citations

Abstract PDF

This paper reports the effect of sintering processes and additives on the microstructures and mechanical properties of ZrB_2-SiC composite ceramics. We fabricated sintered bodies of ZrB_2-20 vol.% SiC with or without sintering additive, such as C or B_4C, densified by spark plasma sintering as well as hot pressing. While almost full densification was achieved regardless of sintering processes or sintering additives, significant grain growth was observed in the case of spark plasma sintering, especially with B_4C. With sintered bodies, mechanical properties, such as flexural strength and Vickers hardness, were also examined.

Citations

Citations to this article as recorded by

Effect of the Size and Amount of SiC on the Microstructures and Thermal Conductivities of ZrB2-SiC Composite Ceramics
Seong-Won Kim, Chang-Sup Kwon, Yoon-Suk Oh, Sung-Min Lee, Hyung-Tae Kim
Journal of Korean Powder Metallurgy Institute.2012; 19(5): 379. CrossRef

Phase Evolution and Thermo-physical Properties of La₂(Zr_1-xHf_x)₂O₇ Oxides for Thermal Barrier Coatings: Seong-Won Kim, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang; J Korean Powder Metall Inst. 2011;18(6):568-574.; DOI: https://doi.org/10.4150/KPMI.2011.18.6.568

19 View
0 Download
2 Citations

Abstract PDF

As operating temperatures of engines or turbines continually increase for higher efficiency, significant amounts of researches have been focused on finding new materials, which would be alternatives to conventional yttria-stabilized zirconia (YSZ) for thermal barrier coatings (TBCs). In this study, phase evolution and thermo-physical properties of La_2(Zr_1-xHf_x)_2O_7 pyrochlore systems are investigated for TBC applications. La_2(Zr_1-xHf_x)_2O_7 systems are comprised by selecting La3+ as A-site ions and Zr4+/Hf4+ as B-site ions in A_2B_2O_7 pyrochlore structures. For the developed phases in La_2(Zr_1-xHf_x)_2O_7 compositions, thermo-physical properties such as thermal conductivity, thermal expansion coefficient are examined. The potential of these La_2(Zr_1-xHf_x)_2O_7 compositions for TBC application is also discussed.

Citations

Citations to this article as recorded by

Preparation of Suspension in La2O3-Gd2O3-ZrO2System via Planetary Mill and Characteristics of (La1-xGdx)2Zr2O7Coatings Fabricated via Suspension Plasma Spray
Chang-Sup Kwon, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang, Seongwon Kim
Journal of Korean Powder Metallurgy Institute.2013; 20(6): 453. CrossRef
Phase Evolution and Thermal Conductivities of (La1-xGdx)2Zr2O7Oxides for Thermal Barrier Coatings
Chang-Sup Kwon, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang, Seong Won Kim
Journal of Korean Powder Metallurgy Institute.2012; 19(6): 429. CrossRef

Phase Evolution and Thermo-physical Properties of Rare-earth Oxides for Thermal Barrier Systems: Byung-Chul Shim, Kil-Ho Kwak, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang, Seong-Won Kim; J Korean Powder Metall Inst. 2010;17(2):148-153.; DOI: https://doi.org/10.4150/KPMI.2010.17.2.148

18 View
0 Download
2 Citations

Abstract PDF

Thermal barrier systems have been widely investigated over the past decades, in order to enhance reliability and efficiency of gas turbines at higher temperatures. Yttria-stabilized zirconia (YSZ) is one of the most leading materials as the thermal barriers due to its low thermal conductivity, thermodynamic stability, and thermal compatibility with metal substrates. In this work, rare-earth oxides with pyrochlore phases for thermal barrier systems were investigated. Pyrochlore phases were successfully formed via solid-state reactions started from rare-earth oxide powders. For the heat-treated samples, thermo-physical properties were examined. These rare-oxide oxides showed thermal expansion of 9sim12times10-6/K and thermal conductivity of 1.2~2.4 W/mK, which is comparable with the thermal properties of YSZ.

Citations

Citations to this article as recorded by

Phase Evolution and Thermal Conductivities of (La1-xGdx)2Zr2O7Oxides for Thermal Barrier Coatings
Chang-Sup Kwon, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang, Seong Won Kim
Journal of Korean Powder Metallurgy Institute.2012; 19(6): 429. CrossRef
Phase Evolution and Thermo-physical Properties of La2(Zr1-xHfx)2O7Oxides for Thermal Barrier Coatings
Seong-Won Kim, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Byung-Koog Jang
Journal of Korean Powder Metallurgy Institute.2011; 18(6): 568. CrossRef

Fabrication of ZrB₂-based Composites for Ultra-high Temperature Materials: Seong-Won Kim, Jung-Min Chae, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim, Sahn Nahm; J Korean Powder Metall Inst. 2009;16(6):442-448.; DOI: https://doi.org/10.4150/KPMI.2009.16.6.442

17 View
0 Download
1 Citations

Abstract PDF

ZrB_2-based composites are candidate materials for ultra-high temperature materials (UHTMs). ZrB_2 has become an indispensable ingredient in UHTMs, due to its high melting temperature, relatively low density, and excellent resistance to thermal shock or oxidation. ZrB_2 powders are usually synthesized by solid state reactions such as carbothermal, borothermal, or combined carbothermal reaction. SiC is added to this system in order to enhance the oxidation resistance of ZrB_2. In this study, ZrB_2?based composites were successfully synthesized and densified through two different processing paths. ZrB_2 or ZrB_2 25 vol.%SiC was fully synthesized from oxide starting materials with reducing agents after heat treatment at 1400°C. Besides, ZrB_2?20 vol.%SiC was fully densified with B_4C as a sintering additive after hot pressing at 1900°C. The synthesis mechanism and the effect of sintering additives on densification of ZrB_2 ?SiC composites were also discussed.

Citations

Citations to this article as recorded by

The Effect of Sintering Processes and Additives on the Microstructures and Mechanical Properties of ZrB2-SiC Composite Ceramics
Chang-Sup Kwon, Jung-Min Chae, Hyung-Tae Kim, Kyung-Ja Kim, Seong-Won Kim
Journal of Korean Powder Metallurgy Institute.2011; 18(6): 562. CrossRef

Feasibility Test for Mechanical Property Characterization of BaTiO₃ Ceramics for MLCC Application Using Nanoindentation: Sung-Soo Ryu, Seong-Won Kim, Hyeong-Jun Kim, Hyung-Tae Kim; J Korean Powder Metall Inst. 2009;16(1):37-42.; DOI: https://doi.org/10.4150/KPMI.2009.16.1.037

15 View
0 Download

Abstract PDF: In this study, the feasible test for the mechanical property characterization of BaTiO_3 ceramics and multi-layer ceramic capacitor(MLCC) was performed with nanoindentation technique. In case of BaTiO_3 ceramics, hardness and elastic modulus are dependent on the densification of specimen showing the highest hardness and elastic modulus values of 12.3 GPa and 155 GPa, respectively at 1260°C. In case of MLCC chip, hardness of dielectric layer was lower than that of margin region. The nanoindentation method could be useful tool for the measurement of mechanical property within BaTiO_3 dielectric layer of very thin thickness in high capacitance MLCC.

Characterization of Ti(C,N) Solid Solutions in Densified Ti(C,N) and TiC-TiN-Ni Cermet: Seong-Won Kim, Jung-Min Chae, Shin-Hoo Kang, Sung-Soo Ryu, Hyung-Tae Kim; J Korean Powder Metall Inst. 2008;15(6):503-508.; DOI: https://doi.org/10.4150/KPMI.2008.15.6.503

14 View
0 Download

Abstract PDF: Ti(C,N) solid solutions in hot-pressed Ti(C_xN_1-x) (x=0.0, 0.3, 0.5, 0.7, 1.0) and 40TiC-40TiN-20Ni (in wt.%) cermet were characterized in this study. For hot-pressed Ti(C,N)s, the lattice parameters and hardness values of Ti(C,N) were determined by using XRD (X-Ray Diffraction) and nanoindentation. The properties of hot-pressed Ti(C,N) samples changed linearly with their carbon or nitrogen contents. For the TiC-TiN-Ni cermet, the hardness of the hard phase and binder phase were determined by nanoindentation in conjunction with microstructural observation. The measured hardness values were sim8.7 GPa for the binder phase and sim28.7 GPa for the hard phase, which was close to the hardness of hot-pressed Ti(C_0.7N_0.3).

Measurement of Hardness of Constituent Phases in Ti(C_0.7N_0.3)-NbC-Ni Cermets Using Nanoindentation: Seong-Won Kim, Dae-Min Kim, Shin-Hoo Kang, Sung-Soo Ryu, Hyung-Tae Kim; J Korean Powder Metall Inst. 2008;15(6):482-488.; DOI: https://doi.org/10.4150/KPMI.2008.15.6.482

14 View
0 Download

Abstract PDF: The indentation technique has been one of the most commonly used techniques for the measurement of the mechanical properties of materials due to its experimental ease and speed. Recently, the scope of indentation has been enlarged down to the nanometer range through the development of instrumentations capable of continuously measuring load and displacement. In addition to testing hardness, the elastic modulus of submicron area could be measured from an indentation load-displacement (P-h) curve. In this study, the hardness values of the constituent phases in Ti(C_0.7N_0.3)-NbC-Ni cermets were evaluated by nanoindentation. SEM observation of the indented surface was indispensable in order to separate the hardness of each constituent phase since the Ti(C_0.7N_0.3)-based cermets have relatively inhomogeneous microstructure. The measured values of hardness using nanoindentation were sim20 GPa for hard phase and sim10 GPa for binder phase. The effect of NbC addition on hardness was not obvious in this work.

Author index