Realization of tough ceramics with photoplastic effect induced by defect engineering

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K18878
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Tohoku University
• Principal Investigator: ANDO Daisuke 東北大学, 工学研究科, 准教授 (50615820)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: セラミックス / 光塑性効果 / 双晶界面 / 相変態

Outline of Final Research Achievements

This study challenges the stereotype that ceramics are brittle by achieving the photoplastic effect in ceramics through defect engineering, in which intentional two-dimensional defects are tempered. As a result, it was found that Cr-doped Al2O3 films can be plastically deformed while producing numerous stacking defects. However, since the amount of plastic deformation was slight, we searched for other Al-based oxides and found that strontium aluminate (SrAl2O4), which is famous as a phosphor, can be quasi-elastically deformed by moving the twin interface, and we further improved its performance by controlling the phase stability by adding Ba The performance was further improved by controlling the phase stability with the addition of Ba.

Free Research Field

金属組織学

Academic Significance and Societal Importance of the Research Achievements

SDGsが提唱する低炭素化社会は熱機関の高温化で成し遂げられる。次々世代の耐熱材料は高融点で耐酸化性が良いセラミックスでしか成し遂げられない。しかし、高温で高強度な材料は室温で脆くて壊れやすいという欠点を持つ。この欠点を克服した軽量セラミックス創製に挑戦した。結果、Cr添加Al2O3膜は多数の積層欠陥を生じながら塑性変形が可能であることが明らかになった。一方で、その塑性変形量はわずかであったので、他のAlベースの酸化物を探索し、蛍光体で有名なアルミン酸ストロンチウム（SrAl2O4）が双晶界面を移動させることで擬弾性変形し、Ba添加することで相安定性を制御することでその性能をさらに向上させた。