Heterogeneous structure control and enhancement of fracture toughness in beta titanium alloys using elemental segregation

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420733
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: National Institute for Materials Science
• Principal Investigator: EMURA Satoshi 国立研究開発法人物質・材料研究機構, 構造材料研究拠点, 主幹研究員 (00354184)
• Co-Investigator(Renkei-kenkyūsha): TSUCHIYA Koichi 物質・材料研究機構, 構造材料研究拠点, 拠点長 (50236907)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ベータ型チタン合金 / 偏析 / ヘテロ構造 / 靭性 / オメガ相 / 変形モード

Outline of Final Research Achievements

In this study, the effects of heterogeneous structure caused by elemental segregation of Mo such as swirly segregation (VGS structure) on fracture toughness of beta type Ti-Mo alloys were investigated. Basic studies on the effects of segregation structure on mechanical properties (ductility and fracture toughness) and deformation mechanism were also performed. Heterogeneous precipitation of omega phase (hard second phase) corresponding to segregation structure enhanced the Charpy absorbed energy. Enhancement of Charpy absorbed energy was remarkable at 473K, while tensile ductility enhanced especially at room temperature. Heterogeneous omega phase precipitation due to segregation structure also enhanced room temperature fracture toughness values.

Free Research Field

材料工学