Developing models for CALPHAD-type phase diagrams that directly consider the effect of structural point defects

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15273
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Tohoku University
• Principal Investigator: Davey Theresa 東北大学, 工学研究科, 特任助教 (10816987)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: zirconium carbide / CALPHAD / phase diagram / defect ordering / vacancies / short-range ordering

Outline of Final Research Achievements

Phase diagrams are used to design materials for a given application, and are commonly created using a well-known set of thermodynamic models. However, for certain materials such as zirconium carbide, the very high numbers of structural defects mean that the widely-used models do not describe their properties accurately. This work uses theoretical calculations to uncover the physical mechanisms behind the behaviour of these defects, and to develop new models for zirconium carbide that incorporate information about these structural vacancies to give a more accurate picture of the material.

Free Research Field

Computational thermodynamics

Academic Significance and Societal Importance of the Research Achievements

The developed models will aid targeted design of highly-specialised materials that will help to realize advanced nuclear and aerospace technologies. These models advance the state-of-the-art of phase diagram accuracy and can also be used in other materials with many structural defects.