Stainless steel thin films as a 2-dimensional stress distribution recording medium using stress-induced phase transformation

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K04094
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: University of Hyogo
• Principal Investigator: Inoue Shozo 兵庫県立大学, 工学研究科, 教授 (50193587)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: SUS304鋼ステンレス / 薄膜 / スパッタリング / 相変態

Outline of Final Research Achievements

Since SUS304 stainless steel is metastable austenite and exhibits stress-induced transformation, SUS304 stainless steel films have the potential to be used as a medium for recording two-dimensional stress distribution. However, the SUS304 steel film prepared by the sputtering has an α phase different from that of the bulk, so this kind of research has not been done. In this study, we have investigated the sputtering conditions for the stable formation of γ-phase SUS304 steel thin films. As a result, it was found that not only the substrate temperature (~600C) and the substrate material (Cu is the best) and conditions under which ion irradiation is suppressed are very important. In addition, it was confirmed that the fabricated thin film undergoes stress-induced γ→α transformation, suggesting the possibility of future media development.

Free Research Field

薄膜工学

Academic Significance and Societal Importance of the Research Achievements

SUS304ステンレス鋼は耐食性や機械的性質に優れているので、薄膜化できれば新しい用途が広がることが期待できる。しかし、スパッタ法で室温の基板上に薄膜を成長させると、バルクとは異なったα相となってしまうため、バルクと同じγ相の薄膜の特性は調査されていなかった。本研究では、γ相の薄膜を安定に成長させる条件を確立し、同じ組成で異なった相の薄膜の特性を調査しようとしたことに学術的な意義がある。また、応力によってバルクと同様のγ→α相変態が誘起できたので、応力が加わった部分を２次元的に記録できるメディアのような新しい用途の可能性を示すことができたという点で意義深い。