Design and microstructure control of aluminum based superalloys based on thermodynamic calculation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03411
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Nagoya University
• Principal Investigator: Takata Naoki 名古屋大学, 工学研究科, 准教授 (70432523)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: アルミニウム合金 / 金属間化合物 / 計算状態図 / 析出 / 高温強度

Outline of Final Research Achievements

We designed an aluminum (Al)-based alloy with the alpha-Al (fcc) matrix strengthened by the T-Al6Mg11Zn11 (cubic) intermetallic phase using a large two-phase region of alpha and T phases in the Al-Mg-Zn ternary system. Thermodynamic calculations assessed a composition of Al-5Mg-3.5Zn (at.%) for the designed alloy. The granular precipitates of the T phase were dispersed rather homogenously in the alpha-Al matrix at temperatures above 300°C. After aging at 200°C, numerous fine precipitates with a mean size of ~20 nm in the grain interior were observed. The present alloy (pre-aged at 200°C for 1 h) exhibited a high yield strength of approximately 260 MPa at 200°C, much higher than those of the conventional Al alloys.

Free Research Field

材料組織学

Academic Significance and Societal Importance of the Research Achievements

現状，耐熱性アルミニウム（Al）合金が自動車用エンジンのターボチャージャにおける圧縮機内部のインペラに使用されている．既存の合金の適応限界温度は160～180℃であり，エンジン高効率化には圧縮機内部の高温・高圧化による圧縮比向上の観点から，高温強度の向上が要求されているが，本研究はその社会的要求を満たす新たな耐熱Al合金の設計原理の基盤を構築したものである．