[1] H.D. Vu, M. Nanko, Crack-healing performance and oxidation behavior of SiC dispersed
yttrium silicate composites, J. Asian Ceram. Soc. 8 (2020) 298–308.
[2] J. Roy, S. Chandra, S. Das, S. Maitra, Oxidation behaviour of silicon carbide-a review, Rev.
Adv. Mater. Sci. 38 (2014) 29–39.
[3] S.T. Nguyen, T. Nakayama, H. Suematsu, T. Suzuki, L. He, H.B. Cho, K. Niihara, Strength
improvement and purification of Yb2Si2O7-SiC nanocomposites by surface oxidation
treatment, J. Am. Ceram. Soc. 100 (2017) 3122–3131.
[4] T. Osada, T. Hara, M. Mitome, S. Ozaki, T. Abe, K. Kamoda, T. Ohmura, Self-healing by
design: universal kinetic model of strength recovery in self-healing ceramics, Sci. Technol.
Adv. Mater. 21 (2020) 593–608.
[5] T. Osada, K. Kamoda, M. Mitome, T. Hara, T. Abe, Y. Tamagawa, W. Nakao, T. Ohmura,
A Novel Design Approach for Self-Crack-Healing Structural Ceramics with 3D Networks
of Healing Activator, Sci. Rep. 7 (2017) 17853.
[6] X. Chen, Y. Li, W. Zhou, P. Xiao, P. Chen, Y. Tong, M. Chen, Interaction of Yb2Si2O7
environmental barrier coating material with Calcium-Ferrum-Alumina-Silicate (CFAS) at
high temperature, Ceram. Int. 47 (2021) 31625–31637.
[7] E. Bakan, D. Marcano, D. Zhou, Y. J. Sohn, G. Mauer, R. Vaßen, Yb2Si2O7 Environmental
Barrier Coatings Deposited by Various Thermal Spray Techniques: A Preliminary
Comparative Study, J. Therm. Spray Technol. 26 (2017) 1011–1024.
[8] S.T. Nguyen, T. Nakayama, H. Suematsu, H, Iwasawa, T. Suzuki, Y. Otsuka, L. He, T.
Takahashi, K. Niihara, Self-healing behavior and strength recovery of ytterbium disilicate
ceramic reinforced with silicon carbide nanofillers, J. Eur. Ceram. Soc. 39 (2019) 3139–
3152.
182
[9] W. Kunz, H. Klemm, A. Michaelis, Crack-healing in ytterbium silicate filled with silicon
carbide particles, J. Eur. Ceram. Soc. 40 (2020) 5740–5748.
[10] L.R. Turcer, A.R. Krause, H.F. Garces, L. Zhang, N.P. Padture, Environmental-barrier
coating ceramics for resistance against attack by molten calcia-magnesia-aluminosilicate
(CMAS) glass: Part II, β-Yb2Si2O7 and β-Sc2Si2O7, J. Eur. Ceram. Soc. 38 (2018) 3914–
3924.
[11] J. Liu, L. Zhang, Q. Liu, L. Cheng, Y. Wang, Structure design and fabrication of
environmental barrier coatings for crack resistance, J. Eur. Ceram. Soc. 34 (2014) 2005–
2012.
[12] Y. Suzuki, P.E.D. Morgan, K. Niihara, Improvement in mechanical properties of powderprocessed MoSi2 by the addition of Sc2O3 and Y2O3, J. Am. Ceram. Soc. 81 (1998) 3141–
3149.
[13] A.J. Fernandez-Carrion, M. Allix, A.I. Becerro, Thermal expansion of rare-earth
pyrosilicates, J. Am. Ceram. Soc. 96 (2013) 2298–2305.
[14] Z. Li, R. C. Bradt, Thermal expansion of the cubic (3C) polytype of SiC, J. Mater. Sci. 21
(1986) 4366–4368.
[15] K. Niihara, A. Nakahira, T. Hirai, The effect of stoichiometry on mechanical properties of
boron carbide, J. Am. Ceram. Soc. 67 (1984) C-13.
[16] L.F. He, J. Shirahata, T. Nakayama, T. Suzuki, H. Suematsu, I. Ihara, Y.W. Bao, T.
Komatsu, K. Niihara, Mechanical properties of Y2Ti2O7, Scr. Mater. 64 (2011) 548–551.
[17] A. Okawa, S.T. Nguyen, J.P. Wiff, H.-W. Son, T. Nakayama, H. Hashimoto, T. Sekino,
T.M.D. Do, H. Suematsu, T. Suzuki, T. Goto, K. Niihara, Self-healing ability, strength
enhancement, and high-temperature oxidation behavior of silicon carbide-dispersed
ytterbium disilicate composite for environmental barrier coatings under isothermal heat
treatment, J. Eur. Ceram. Soc 42 (2022) 6170–6181.
183
[18] B.K. Jang, H. Matsubara, Influence of porosity on hardness and Young’s modulus of
nanoporous EB-PVD TBCs by nanoindentation, Mater. Lett. 59 (2005) 3462–3466.
[19] B.K. Jang, S.H. Kim, C.A.J. Fisher, H.T. Kim, Effect of isothermal heat treatment on
nanoindentation hardness and Young’s modulus of 4 mol% Y2O3-ZrO2 EB-PVD TBCs,
Mater. Today Commun. 31 (2022) 103330.
[20] W.C. Oliver, G.M. Pharr, Measurement of hardness and elastic modulus by instrumented
indentation: Advances in understanding and refinements to methodology, J. Mater. Res. 19
(2004) 3–20.
[21] M. Ojovan, Glass formation in amorphous SiO2 as a percolation phase transition in a
system of network defects, J. Exp. Theor. Phys. Lett. 79 (2004) 632–634.
[22] D. Maruoka, M. Nanko, Improved crack healing and high‐temperature oxidation
resistance of Ni/Al2O3 by Y or Si doping, J. Am. Ceram. Soc. 99 (2016) 2451–2457.
[23] M. Yuan, L. Liu, J. Wang, Q. Hu, H. Zhang, S. Zhang, X. Zhou, Crack-healing behaviour
of MoSi2 dispersed Yb2Si2O7 environmental barrier coatings, Ceram. Int. 48 (2022)
29919–29928.
[24] A. Okawa, S.T. Nguyen, J.P. Wiff, H.-W. Son, T. Nakayama, T.M.D. Do, H. Suematsu,
T. Suzuki, T. Goto, K. Niihara, Autonomous crack healing ability of SiC dispersed
Yb2Si2O7 by oxidations in air and water vapor, Ceram. Int. 47 (2021) 34802–34809.
[25] B. Chayasombat, T. Kato, T. Hirayama, T. Tokunaga, K. Sasaki, K. Kuroda, Oxidation
kinetics of single crystal silicon carbide using electron microscopy, J. Ceram. Soc. Jpn.
120 (2012) 181–185.
[26] C. Varadachari, R. Bhowmick, K. Ghosh, Thermodynamics and oxidation behaviour of
crystalline silicon carbide (3C) with atomic oxygen and ozone, ISRN Thermodyn. 2012
(2012) 1–8.
184
[27] S. Kitaoka, T. Matsudaira, M. Wada, T. Saito, M. Tanaka, Y. Kagawa, Control of oxygen
permeability in alumina under oxygen potential gradients at high temperature by dopant
configurations, J. Am. Ceram. Soc., 97 (2014) 2314–2322.
[28] S. Kitaoka, T. Matsudaira, M. Wada, T. Saito, M. Tanaka, Y. Kagawa, Effect of dopants
on the distribution of aluminum and oxygen fluxes in polycrystalline alumina under
oxygen potential gradients at high temperatures, J. Am. Ceram. Soc., 96 (2013) 3243–
3251.
[29] S. Kitaoka, T. Matsudaira, D. Yokoe, T. Kato, M. Takata, Oxygen permeation mechanism
in polycrystalline mullite at high temperatures, J. Am. Ceram. Soc., 100 (2017) 3217–3226.
[30] T. Matsudaira, B.K. Jang, S.D. Kim, S.K. Woo, Effect of water vapor on static fatigue
behavior of a nickel/yttria-stabilized zirconia composite, J. Ceram. Soc. Jpn., 125 (2017)
416–418.
[31] M. Wada, T. Matsudaira, N. Kawashima, M. Takeuchi, D. Yokoe, T. Ogawa, T. Kato, M.
Takata, S. Kitaoka, Effect of water vapor on mass transfer in polycrystalline Yb2Si2O7
under oxygen potential gradients at high temperatures, Acta Mater. 201 (2020) 373–385.
[32] M. Tanaka, T. Matsudaira, E. Kawai, N. Kawashima, U. Matsumoto, T. Ogawa, M.
Takeuchi, S. Kitaoka, Effect of chemical composition on mass transfer in Y2Ti2O7 under
oxygen potential gradient at high temperatures, J. Ceram. Soc. Jpn. 129 (2021) 22–31.
[33] T. Matsudaira, M. Wada, N. Kawashima, M. Takeuchi, D. Yokoe, T. Kato, M. Takata, S.
Kitaoka, Mass transfer in polycrystalline ytterbium monosilicate under oxygen potential
gradients at high temperatures, J. Eur. Ceram. Soc. 41 (2021) 3150–3160.
185
[34] M. Wada, T. Matsudaira, N. Kawashima, S. Kitaoka, M. Takata, Mass transfer in
polycrystalline ytterbium disilicate under oxygen potential gradients at high temperatures,
Acta Mater. 201 (2017) 372–381.
186
Chapter 8. Conclusions
This thesis addressed a successful conclusion on the chemical and physical factors
affecting the durability of EBCs. For the success of this study, a complete understanding of
RE-silicate and optimization of parameters affecting high-temperature corrosion behavior and
self-healing properties are required. RE-silicates exhibit many attractive properties such as high
temperature resistance, low coefficient of thermal expansion (CTE), good chemical stability
and good adhesion to SiC. In this study, according to the variables of CaO:SiO2 (volcanic ash
and CMAS), disilicate (RE2Si2O7) and monosilicate (RE2SiO5), ionic radius, time, and dual
disilicate which are major factors affecting the high-temperature corrosion behavior of REsilicate applied to EBCs, was evaluated. In addition, it was evaluated according to the variables
of time, temperature, and SiC vol%, which are major factors affecting the self-healing
characteristics. The main challenge was to improve the high-temperature corrosion and selfhealing properties of RE-silicates applied to EBCs. The following is a successful summary
conclusion of each chapter.
Chapter 2. High-Temperature Corrosion of Gd2SiO5 with Volcanic Ash for EBCs
The high-temperature corrosion behavior of sintered Gd2SiO5 produced by the SPS process
on volcanic ash was evaluated at 1400°C for 2, 12, and 48 h. As a result of this confirmed
through HT-XRD, it was confirmed that the volcanic ash was melted at 1300°C and reacted
with Gd2SiO5 to form a reaction layer. The elongated shape of Ca2Gd8(SiO4)6O2 particles
observed in the reaction layer became thicker as the heat treatment time increased as the
volcanic ash was dissolved. The reaction layer after heat treat times for 48 h was measured to
45 μm. A suitable reaction layer (Ca2Gd8(SiO4)6O2) formed by the reaction of Gd2SiO5 with
the volcanic ash acts as a protective layer against further attack by the molten volcanic ash.
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Chapter 3. High-Temperature Corrosion of Gd2SiO5 with CMAS for EBCs
In this study, the high-temperature corrosion behavior of CMAS on sintered Gd2SiO5 was
performed at 1400°C for 2, 12, and 48 h. Attack of dissolved CMAS reacted with sintered
Gd2SiO5 to form a reaction layer. The vertically elongated needle shape of the
Ca2Gd8(SiO4)6O2 particles analyzed in the reaction layer became thicker as the heat treatment
time increased as the CMAS dissolved. As a result of HT-XRD analysis, it can be confirmed
that CMAS is dissolved at 1300°C and reacts with Gd2SiO5. Ca, a major corrosion factor in
CMAS, reacted with Gd2SiO5 to form Ca2Gd8(SiO4)6O2 phase. After reaction times of 48 h,
reaction layer was measured to 120 μm. Due to the higher CaO:SiO2 ratio (0.73) of CMAS
than that of volcanic ash (0.11) in chapter 2, a thicker reaction layer was formed than that of
volcanic ash.
Chapter 4. High-Temperature Corrosion of Gd2Si2O7 with CMAS for EBCs
In this study, high-temperature corrosion behavior of CMAS coated sintered Gd2Si2O7 was
investigated at 1400°C for 100 h to evaluate their suitability as EBC materials. The
Ca2Gd8(SiO4)6O2 (apatite) phase formed in the reaction between molten CMAS and Gd2Si2O7,
was analyzed using HT-XRD at 1300°C. As the heat-treatment time increased, the thickness
of the reaction layer increased because of the reaction between CMAS and sintered Gd2Si2O7,
and the reaction layer grew vertically at the Gd2Si2O7 interface. With the extension of the
reaction time from 0.5 to 100 h, the thickness of the reaction layer increased from
approximately 98 to 315 μm. The thickness of the reaction layer was found to increase in the
form of a parabola. The width of the apatite increased from 2.6 to 14.6 μm with increasing time
from 0.5 to 100 h, respectively. RE2Si2O7 reacts with CaO in the melt to form the apatite phase,
releasing SiO2, whereas RE2SiO5 reacts with both CaO and SiO2, with only the apatite phase
being produced. Therefore, Ca2+ is depleted more quickly and the amount of apatite formed
188
from the RE2SiO5 in chapter 3 is reduced, it was confirmed that the reaction layer was thicker
in RE2Si2O7 than in RE2SiO5.
Chapter 5. High-Temperature Corrosion of Er2Si2O7 with CMAS for EBCs
To evaluate their suitability as EBC materials, the high-temperature corrosion behavior of
Er2Si2O7 sintered with CMAS was investigated. The sintered Er2Si2O7 was exposed at 1400°C
for 48 h with CMAS. As a result of DSC analysis, the melting temperature of the mixed CMAS/
Er2Si2O7 powder mixture was 1258°C, confirming that the reaction between the two materials
occurred at a high temperature. The reaction between CMAS and Er2Si2O7 was also confirmed
by the results of HT-XRD, and the Ca2Er8(SiO4)6O2 apatite phase was observed above 1300℃
as a result of the reaction between molten CMAS and Er2Si2O7. Ca2Er8(SiO4)6O2 grew
vertically on the Er2Si2O7 surface as the heat treatment time increased. Compared to the
reaction layer of Gd2Si2O7 in chapter 4, Er (1.004 Å) has a small ionic radius and has a weak
affinity for Ca among CMAS components, forming a reaction layer thinner than Gd (1.107 Å).
Chapter 6. High-Temperature Corrosion of Gd2Si2O7/Sc2Si2O7 with CMAS for EBCs
In this study, the high-temperature corrosion behavior by CMAS of sintered composite
Gd2Si2O7(70%)+Sc2Si2O7(30%) as EBC material was investigated at 1400°C for 48 h. The
reaction layer produced at high temperature was classified into two layers. In the top region,
Ca2Gd8(SiO4)6O2 (apatite) grown in the form of elongated needles by reaction of a single
Gd2Si2O7 with CMAS was analyzed. In the lower region where Gd2Si2O7(70%)+Sc2Si2O7(30%)
components are mixed, Ca2Gd8(SiO4)6O2 was also analyzed. Gd2Si2O7 has a large ionic radius,
Gd (1.107 Å) showed a great affinity for Ca among CMAS components. However, Sc (0.870Å)
with small ionic radius does not form apatite and is controlled by the penetration of molten
CMAS along grain boundaries. Comparing the reaction layer for single Gd2Si2O7 in chapter 5
189
and CMAS, the thickness of the reaction layer of Gd2Si2O7 (70%)+Sc2Si2O7 (30%) was 20%
(306 → 238 μm) decreased.
Chapter 7. Self-Healing Behavior of RE2Si2O7/SiC Composites for EBCs
We investigated the self-healing behavior of Sc2Si2O7/10 vol.% SiC and Yb2Si2O7/20 vol.%
SiC composites as a function of temperature and time in an oxidizing environment to evaluate
their suitability for use as EBC materials. After artificially induced cracks, the specimens were
exposed to air at 1100 or 1300°C for 0.5, 2, 5 or 10 h. The cracks did not fully recover after 10
h at 1100°C, but fully recovered after 5 h at 1300°C in Sc2Si2O7/10 vol.% SiC. Crack recovery
after 2 h at 1100°C was about 10% , but at 1300°C a recovery of more than 90% was achieved
from 0.5 h in Yb2Si2O7/20 vol.% SiC. Exposure to air was found to create oxidized regions
within the composite at the exposed surfaces, with deeper oxidized regions formed at 1300°C
than at 1100°C after the same time. The growth of the oxidized region followed a parabolic
rate law with rate constants of 1.9×10-12 m2/s at 1100ºC and 6.2×10-11 m2/s at 1300ºC. We found
that self-healing causes surface cracks to close by increasing volume when SiC is oxidized to
SiO2.
The main result of this thesis is that the higher the CaO:SiO2 ratios (CMAS: 0.73, volcanic
ash: 0.11), the thicker the high-temperature corrosion reaction layer was formed in RE2Si2O7
(Gd2Si2O7) than in RE2SiO5 (Gd2SiO5). The larger the ionic radius (Gd: 1.107 Å, Er: 1.004 Å)
and the longer the reaction time, the thicker the reaction layer was formed. In addition, it is
possible to control the thickness of the reaction layer by double RE silicate, so the durability
of EBCs is expected to improve. As time (0.5 → 10 h), temperature (1100 → 1300°C), and
SiC vol% (10 → 20 vol.%) increased, the crack healing rate of RE-silicate improved,
demonstrating excellent results.
In the future, this study has academic value as it will contribute to the main parts of aircraft
190
engines and gas turbines for power generation and the field of defense by improving hightemperature corrosion behavior and self-healing due to the development of valuable EBCs
technology.
191
Research Achievements
1. List of published papers
[1] S.H. Kim, T. Osada, Y. Matsushita, T. Hiroto, Craig A.J. Fisher, B.K. Jang, “Corrosion
behavior
of
Gd2Si2O7/Sc2Si2O7
with
calcia-magnesia-alumina-silica
melts
for
environmental barrier coatings”, J. Eur. Ceram. Soc., (2023) in submission.
[2] S.H. Kim, Craig A.J. Fisher, N. Nagashima, Y. Matsushita, B.K. Jang, “Self-healing
behavior of Sc2Si2O7/SiC composites for environmental barrier coatings”, Ceram. Int.,
(2023) in press.
[3] S.H. Kim, N. Nagashima, Y. Matsushita, and B.K. Jang, “Interaction of Gd2Si2O7 with
CMAS melts for environmental barrier coatings”, J. Eur. Ceram. Soc., 43 (2023) 593–599.
[4] S.H. Kim, Craig A.J. Fisher, N. Nagashima, Y. Matsushita, B.K. Jang, “Reaction between
environmental barrier coatings material Er2Si2O7 and a calcia-magnesia-alumina-silica
melt”, Ceram. Int., 48 (2022) 17369–17375.
[5] S.H. Kim, N. Nagashima, Y. Matsushita, B.N. Kim, B.K. Jang, “Corrosion behavior of
calcium-magnesium-aluminosilicate (CMAS) on sintered Gd2SiO5 for environmental
barrier coatings”, J. Am. Ceram. Soc., 104 (2021) 3119–3129.
[6] S.H. Kim, B.N. Kim, N. Nagashima, Y. Matsushita, B.K. Jang, “High temperature
corrosion of spark plasma sintered Gd2SiO5 with volcanic ash for environmental barrier
coatings”, Eur. Ceram. Soc., 41 (2021) 3161–3166.
[7] B.K. Jang, S.H. Kim, Craig A.J. Fisher, H.T. Kim, “Effect of isothermal heat treatment on
nanoindentation hardness and Young’s modulus of 4 mol% Y2O3–ZrO2 EB-PVD TBCs”,
Mater. Today Commun., 31 (2022) 103330.
[8] S.H. Kim, E.R. Baek, B.K. Jang, “The effect of vanadium addition on the fracture and
wear resistance of indefinite chilled cast iron”, Mater. Today Commun., 26 (2021) 101819.
[9] S.H. Kim, Y. Matsushita, B.K. Jang, “Corrosion behavior of sintered YSZ with volcanic
ash for thermal barrier coatings”, Mater. Sci. Tech. Jpn, 57 (2020) 228–234.
- 解説
[1] 金 昇炫、松平
恒昭、張 炳國、“耐環境コーティング用自己亀裂治癒セラミック
スの研究開発動向”、材料の科学と工学、59 (2022) 158–161.
192
2. List of international academic conferences
[1] S.H. Kim, and B.K. Jang, “Self-healing behavior of Sc2Si2O7-SiC by surface oxidation
treatment”, KJMST 2022 (Korea-Japan International Symposium on Materials Science
and Technology 2022), Jeju, Republic of Korea, Poster Presentation, 11/09-11 (2022).
[Best Presentation Awards (Poster)]
[2] S.H. Kim, N. Nagashima, Y. Matsushita, and B.K. Jang, “Self-healing behavior of
Sc2Si2O7 with silicon carbide for environmental barrier coatings”, ICACC 2022 (46th
International Conference and Expo on Advanced Ceramics and Composites), Online
Conference, Oral Presentation, 01/23-28 (2022).
[3] S.H. Kim, and B.K. Jang, Reaction between environmental barrier coatings material
Er2Si2O7 and CMAS, 23rd CSS-EEST (23rd Cross Straits Symposium on Energy and
Environmental Science and Technology), Online Conference, Oral Presentation, 12/02-03
(2021).
[4] S.H. Kim, N. Nagashima, Y. Matsushita, C.A.J. Fisher, and B.K. Jang, “High-temperature
corrosion behavior of calcia-magnesia-alumina-silica on Er2Si2O7 for environmental
barrier coatings”, IEICES-2021 (International Exchange and Innovation Conference on
Engineering & Science), Online Conference, Oral Presentation, 10/21-22 (2021).
[5] S.H. Kim, N. Nagashima, Y. Matsushita, and B.K. Jang, “High-temperature corrosion of
sintered Er2Si2O7 with CMAS for environmental barrier coatings”, ICMCTF 2021 (47th
The International Conference on Metallurgical Coatings and Thin Films), Online
Conference, Oral Presentation, 04/26-30 (2021).
[6] S.H. Kim, B.N. Kim, B.K. Jang, “High temperature corrosion of spark plasma sintered
Gd2SiO5 with calcium-magnesium-aluminosilicate (CMAS) and volcanic ash”, ICC8 (8th
International Congress on Ceramics), Online Conference, Oral Presentation, 04/25-30
(2021).
[7] S.H. Kim, N. Nagashima, Y. Matsushita, and B.K. Jang, “Corrosion behavior of Gd2SiO5
by CMAS under isothermal heat treatment for environmental barrier coatings”, ICACC
2021 (45th International Conference and Expo on Advanced Ceramics and Composites),
Online Conference, Oral Presentation, 02/08-11 (2021).
[8] S.H. Kim, N. Nagashima, Y. Matsushita, and B.K. Jang, “High-temperature corrosion of
sintered Gd2SiO5 with CMAS for environmental barrier coatings”, 22nd CSS-EEST (22nd
Cross Straits Symposium on Energy and Environmental Science and Technology), Online
Conference, Oral Presentation, 12/02-03 (2020).
193
3. List of domestic academic conferences
[1]
金 昇炫、長島 伸夫、松下 能孝、張 炳國、“カルシア-マグネシア-アルミナ-シリ
カ(CMAS)に対するガドリニウムモノ及びデシリケ-トの抵抗性”、日本セラミ
ックス協会 第 35 回秋季シンポジウム、徳島大学 常三島キャンパス、09/14-16
(2022)。
[2]
金 昇 炫 、 長 島 伸 夫 、 松 下 能 孝 、 張 炳 國 、“High-Temperature Corrosion of
Gd2Si2O7 with CMAS for Environmental Barrier Coatings”、日本材料科学会、2022
年度学術講演大会、オンライン開催、05/18-19 (2022)。
[3]
金 昇炫、長島 伸夫、松下 能孝、張 炳國、“Interaction of gadolinium disilicate
environmental barrier coatings with calcium-magnesium-aluminosilicate melts”、日本
セラミックス協会 2022 年年会、オンライン開催、03/10-12 (2022)。
[4]
金 昇炫、長島 伸夫、松下 能孝、張 炳國、“表面酸化処理による Sc2Si2O7-SiC の
自己治癒挙動”、日本セラミックス協会 第 34 回秋季シンポジウム、オンライン
開催、09/01-03 (2021)。
[5]
金 昇炫、長島 伸夫、松下 能孝、張 炳國、“High Temperature Corrosion Behavior
of CMAS on Er2Si2O7 for Environmental Barrier Coatings”、日本材料科学会、2021
年度学術講演大会、オンライン開催、05/20-21 (2021)。
[6]
金 昇炫、長島 伸夫、松下 能孝、張 炳國、“High-temperature corrosion behavior of
calcium-magnesium-aluminosilicate (CMAS) on sintered Er2Si2O7 for environmental
barrier coatings”、日本セラミックス協会 2021 年年会、オンライン開催、03/2325 (2021)。
[7]
金 昇炫、長島 伸夫、松下 能孝、張 炳國、“CMAS に曝された環境バリアコーテ
ィング用の Gd2SiO5 焼結体の劣化メカニズム”、日本セラミックス協会九州支部
2020 年度秋季研究発表会、オンライン開催、11/14 (2020)。
[8]
金 昇 炫 、 金 炳 男 、 張 炳 國 、“High temperature corrosion behavior of sintered
Gd2SiO5 and YSZ”、日本セラミック協会 第 33 回秋季シンポジウム、オンライン
開催、09/02-04 (2020)。
[9]
金 昇 炫 、 金 炳 男 、 張 炳 國 、“Effect of high temperature corrosion of sintered
Gd2SiO5 with CMAS and volcanic ash”、日本材料科学会、2020 年度学術講演大会、
オンライン開催、07/16-17 (2020)。[The MSSJ Prize for the Presentation of an
194
Excellent Paper (Oral)]
[10] 金 昇炫、金 炳男、張 炳國、“High Temperature Corrosion of Sintered Gd2SiO5 with
CMAS and Volcanic Ash”、日本セラミック協会 2020 年年会、オンライン開催、
03/18-20 (2020)。
195
Acknowledgements
Above all, I would like to express my sincere gratitude to Prof. Byung-Koog Jang as
supervisor in Kyushu University. During my doctoral course, I was able to obtain valuable
results from Prof. Jang passionate guidance from the stage of actively and effectively planning
an experiment to writing a thesis. In addition, Prof. Jang gave me the opportunity to see and
learn from the research of many researchers around the world through participation in domestic
and international conferences. Prof. Jang was always busy, but when he was guiding the thesis,
he gave passionate guidance until late at night. I would like to thank Prof. Jang for guiding the
latest technology direction, experimental conditions, and originality for the high-temperature
corrosion behavior of EBCs, and for helping me to select additives for self-healing of EBCs
and to derive successful research results. Also, whenever there was a slump during the doctoral
course, Prof. Jang gave me a clear direction for the future and helped me reach my goal as a
doctoral student through character education. As a result, I was able to achieve excellent
research results and graduate with pride.
I would like to thank Prof. Satoshi Hata and Prof. Kengo Shimanoe for their meaningful
comments as thesis committee. The quality of my graduation thesis was able to improve thanks
to Prof. Satoshi Hata and Prof. Kengo Shimanoe generous teaching and detailed coaching on
writing the graduation thesis.
In the national institute for materials science (NIMS) dispatch research, Dr. Osada Toshio
and Dr. Nagashima Nobuo, who are the advisors for the research topic, gave a lot of help to
the successful dispatch research through in-depth discussions for experiments and thesis
writing on my research topic. I would like to thank Dr. Matsushita Yoshitaka for helping to
lead the research topic through a detailed discussion of HT-XRD analysis. Dr. Craig A.J. Fisher
from Japan Fine Ceramics Center (JFCC) learned a lot about drawing conclusions and overall
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data analysis. In addition, Dr. Matsudaira Tsuneaki from JFCC helped me draw conclusions in
review paper.
In Chikushi campus life, thanks to teacher Ms. Rumiko Ide and Ms. Kyoko Nozoe, I
prepared and practiced school administration and schedule without problems. Also, thanks to
my lab colleagues Ji-Hwoan Lee, Ahrong Jeong. I am deeply grateful for being able to live a
stable life.
I am deeply grateful to my father (Dong-Woan Kim), mother (Hye-Yeon Jo), father-in-law
(Dong-Ryul Seo), and mother-in-law (Young-Soon Kang) for believing in me and supporting
me throughout the doctoral course. And I am always grateful and sorry to my younger sister
(Jae-Won Kim) and wife's brother (Won-Ik Seo) who protected my parents on behalf of me in
Korea. Lastly, I will always love and promise a happy future to my wife (Hwa-Jeong Seo),
who supported me with all of herself during the hardest and most difficult times.
For three years and six months, I was able to endure thanks to the people who have been
here. I will remember and not forget a everything. I will work harder to become a better person
in the future. I sincerely thank everyone for their consideration and kindness. I am very proud
to have graduated from Kyushu University's Chikushi Campus in my life. Lastly, I thank God
for the grace that made all of this possible.
January, 2023
金 昇炫
KIM SEUNG HYEON
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