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Developing CALPHAD-type models for Zr-C-O high-temperature ceramics considering the effects of short-range-ordering

考虑短程有序效应的 Zr-C-O 高温陶瓷的 CALPHAD 型模型

基本信息

批准号：
21K14393
负责人：
DAVEY THERESA
金额：
$ 2.91万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Early-Career Scientists
财政年份：
2021
资助国家：
日本
起止时间：
2021-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-21K14393/
关键词：
zirconium carbide CALPHAD ordering phase diagram high entropy ceramic DFT first-principles zirconia point defects

项目摘要

In FY2022, density functional theory (DFT) calculations were performed to further examine the C-O-Zr system, including improving the cluster expansion method calculations calculated previously and generating special quasirandom structures (SQS) to examine disordered phases at different compositions. The lattice parameter was evaluated for these results and mapped as planned across the calculated composition space. Results were presented at international conferences: MS&T2022 (in-person in Pittsburgh, USA) - Invited, ICAMMM (virtually in Chandigarh, India) - Invited keynote, and international seminars: Thermo-Calc (virtually in Stockholm, Sweden) research webinar - Invited, UC Davis (in-person in Davis, USA) research seminar - Invited.The aim of the proposed work was to explore the C-O-Zr system to understand oxidation behaviour of the ultra-high temperature ceramic (UHTC) ZrC. In very recent years, an exciting new field has emerged of “high-entropy” UHTCs based on the ZrC structure, where Zr is replaced with multi-principal component refractory transition metals such as Zr, Hf, Ti, Ta, Nb. These high-entropy UHTCs have improved oxidation resistance compared to the single metal carbides such as ZrC. Therefore, in addition to exploring the C-O-Zr phase diagram, the properties of some high-entropy UHTCs have also been explored. Results from this work was presented at the ICACC2023 conference (in-person in Daytona Beach, USA), and following this an abstract submitted to ECerS 2023 (to take place in Lyon, France, in July 2023) has been selected as a highlight presentation.

于2022财政年度，进行密度泛函理论（DFT）计算以进一步研究C-O-Zr系统，包括改进先前计算的团簇展开法计算，并产生特殊的准随机结构（SQS）以研究不同组成的无序相。针对这些结果评估晶格参数，并按计划在计算的组成空间上进行映射。结果在国际会议上发表：MS & T2022（在美国匹兹堡亲自）-受邀，ICAMMM（虚拟在印度昌迪加尔）----应邀主题演讲和国际研讨会：Thermo-calc（虚拟在瑞典斯德哥尔摩）研究网络研讨会-特邀，加州大学戴维斯分校（在戴维斯的人，美国）研究研讨会-邀请。拟议工作的目的是探索C-O-Zr系统，以了解超高温陶瓷的氧化行为（UHTC）ZrC。近年来，出现了一个令人兴奋的新领域，即基于ZrC结构的“高熵”UHTCs，其中Zr被多主成分难熔过渡金属如Zr、Hf、Ti、Ta、Nb取代。这些高熵UHTCs与单一金属碳化物如ZrC相比具有改善的抗氧化性。因此，除了探索C-O-Zr相图外，还探索了一些高熵UHTCs的性质。这项工作的结果在ICACC 2023会议上进行了展示（在美国代托纳海滩亲自举行），之后提交给ECerS 2023的摘要（将于2023年7月在法国里昂举行）被选为重点介绍。