Phase diagrams at ultra-high temperatures and high specific strength chromium-based heat-resistant materials

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H00298
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Tohoku University
• Principal Investigator: Omori Toshihiro 東北大学, 工学研究科, 教授 (60451530)
• Co-Investigator(Kenkyū-buntansha): 大沼 郁雄 国立研究開発法人物質・材料研究機構, 構造材料研究拠点, 上席研究員 (20250714)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 状態図 / 相平衡 / Cr合金 / 耐熱材料 / 高温材料

Outline of Final Research Achievements

In this study, for development of Cr-based heat-resistant materials, the Cr-based phase diagrams were experimentally determined, and a thermodynamic database using the CALPHAD method was constructed. Furthermore, we designed alloys using the phase diagram and clarified their potential as high-temperature materials. The melting point of pure Cr, the phase diagrams of the Cr-Si and Cr-Ta binary systems were determined experimentally. The phase diagram of the Cr side of the Cr-Si-Ta ternary system was also determined. Through microstructural control and high-temperature compression tests of the Cr-Si-Ta system, we have shown that it has the potential to become a high-temperature material with toughness and oxidation resistance.

Free Research Field

金属材料学

Academic Significance and Societal Importance of the Research Achievements

本研究ではCr合金を用いて高温の状態図を決定する手法を検討し、Cr-Si系をはじめとして複数の合金系の状態図を決定することができた。高融点金属の状態図は正確な情報が少なく、今後、実験状態図や熱力学データベースの構築が進展することが期待できる。また、高融点利用の一例として、Cr系耐熱材料の開発に取り組んだ。耐熱材料の耐用温度向上は発電の高効率化に寄与することができる。