| 配分額 *注記 |
4,550千円 (直接経費: 3,500千円、間接経費: 1,050千円)
2023年度: 1,170千円 (直接経費: 900千円、間接経費: 270千円)
2022年度: 1,170千円 (直接経費: 900千円、間接経費: 270千円)
2021年度: 2,210千円 (直接経費: 1,700千円、間接経費: 510千円)
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| 研究開始時の研究の概要 |
Zirconium carbide and zirconia ceramics are widely used, but there is limited understanding of the atomic-scale effects of impurities and atomic arrangements. This research will combine insights from several theoretical methods (DFT, CEM, MD) with scale-bridging approaches such as CALPHAD to obtain a self-consistent description of the C-O-Zr phase diagram that may be used for design of tuneable high-temperature ceramics. This will also represent a development in the use of first-principles calculations in CALPHAD modelling by extending previously developed defect-centric models.
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| 研究実績の概要 |
In FY2023, further density functional theory (DFT) calculations were performed to examine the C-O-Zr system and systems related to high entropy transition metal carbides C-O-M, where M represents up to five element mixtures of zirconium, hafnium, titanium, niobium, and tantalum. High entropy carbides, with mixed transition metals of these elements, have potentially preferential oxidation behaviour compared to ZrC and have attracted significant interest. The stability, structural properties, and local bonding of mixtures with 1-5 metals and varying carbon stoichiometries was explored using first-principles calculations.
Results were presented at international conferences and meetings: Thermo-Calc expert users webinar (Sweden) - Invited, ECerS 2023 (France) - Highlight presentation, MS&T2023 (Columbus, USA) - Invited, MS&T2023 (Columbus, USA) - Contributed, ICACC2024 (Daytona Beach, USA) - Invited, Annual Meeting of the Ceramic Society of Japan (Kumamoto, Japan) - Invited.
The Best Paper Award for the International Journal of Ceramic Engineering and Science in 2023 was given for this work published the previous year.
Further abstracts for presentations relating to this work have been given/accepted at the following conferences: UHTC (Sicily, Italy) - Contributed, MRS Spring (Seattle, USA) - Invited, Calphad (Mannheim, Germany) - Contributed, MS&T2024 (Pittsburgh, USA) - Invited.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The plan has been adjusted to account for developments in the field, such as the increased interest in related high entropy ceramics. Additionally, access to computing researches has affected which types of calculations could be performed, so alternatives must be used. However, the initial aims of the project remain the same and we hope to reach the defined goals by the end of the project. This year there was significant opportunity to travel and present the work at many international conferences, and it has attracted a lot of interest and excitement. There are many results to be published soon which are expected to be high impact.
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| 今後の研究の推進方策 |
In the final year of this project, we will focus on the oxidation pathways of ZrC and other multi-principal component transition metal carbides. This will build on the original results, allowing the phase diagram to be calculated and mapped, along with selected structural, thermal, and mechanical properties. CALPHAD modelling of the C-Zr-O system will take place in this year, along with other systems as possible. Calculation of and uncertainty quantification of some M1-M2-C phase diagrams will also take place this year in collaboration with experimental researchers led by Prof. Scott McCormack at UC Davis, USA.
Results are expected to be published this year in several articles, and results will be presented in FY2024 at the following conferences: UHTC (Sicily, Italy) - Contributed, MRS Spring (Seattle, USA) - Invited, Calphad (Mannheim, Germany) - Contributed, MS&T2024 (Pittsburgh, USA) - Invited.
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