Ferroelastic constitutive model contributing to prolongation of SOFC life and establishment of next-generation fuel cell design guideline

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K17977
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Materials/Mechanics of materials
• Research Institution: Keio University (2018); Tohoku University (2016-2017)
• Principal Investigator: Muramatsu Mayu 慶應義塾大学, 理工学部(矢上), 講師 (20609036)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: SOFC / 強弾性 / Phase-field

Outline of Final Research Achievements

In this study, considering the development of microstructure of lanthanum strontium cobalt ferrite (LSCF), which is the cathode electrode of solid oxide fuel cell (SOFC), we developed a mathematical model that can express ferroelastic phenomena in SOFC. We implemented a coupled analysis program of Phase-field and deformation field, calculated macroscopic mechanical properties, and also considered the structure formed in external stress field. In addition, analysis for polycrystalline materials were performed. As a result, it was reproduced that lamellar structures of different variants and orientations were formed depending on the initial nucleation site and crystal orientation. Furthermore, from the analysis in the coupling homogenization method, the macroscopic deformation which occurs during the growth of the ferroelastic phase is shown.

Free Research Field

固体力学，計算力学

Academic Significance and Societal Importance of the Research Achievements

これまでのSOFC性能評価にはもっぱら熱力学的もしくは電気化学的解析が行われてきたが，SOFC長期健全性予測のためには，長期稼動中の組織変化を考慮した変形シミュレーションこそが必要な数値解析となる．本研究は，実験に基づいて材料ダイナミクスレベルで強弾性の構成モデルを提案した．本解析技術によって，強弾性による特異な力学挙動が反映された長期耐久性解析結果を得ることができると予想され，次世代SOFC設計の指針策定がより簡便になる．これはSOFC内で生じる現象を明らかとする基礎研究の点でも，次世代SOFCの耐久性向上においても大きな意義があると考えている．