High-Strength dissimilar material joining using combined friction process and heat treatment and the elucidation of the mechanism of strength development

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02443
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: Osaka University
• Principal Investigator: OGURA TOMO 大阪大学, 工学研究科, 准教授 (90505984)
• Co-Investigator(Kenkyū-buntansha): 才田 一幸 大阪大学, 工学研究科, 教授 (30178470)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 異材接合 / アルミニウム合金 / 組織制御 / 摩擦プロセス / 界面反応

Outline of Final Research Achievements

The purpose of this study was to elucidate the mechanism of high-strength dissimilar-material interface formation and its strength development using a combination of friction process and heat treatment, and to develop a model for the mechanism. By optimizing the process, joining of the same material and A7N01 alloy/SUS304 dissimilar material was achieved with base metal fracture. Numerical analysis of the mechanics revealed that the ultra-high-strength aluminum alloy alloy/SUS304 joints exhibit interface rupture due to local stresses above the nominal stress on the joint at the periphery of the interface. Therefore, it is necessary to take into account the yield stress between the materials and the difference in stress distribution at the interface caused by work hardening in order to construct a model of dissimilar material joints that exhibit base metal fracture.

Free Research Field

溶接・接合

Academic Significance and Societal Importance of the Research Achievements

本研究は界面反応制御と母材強化を並立させている．そのため，研究の展開として，例えばチタン合金など他実用合金においても界面反応による金属間化合物を形成する系において適用が可能であり，それらの異材界面強度の理解が深めることができると考えられる．また，理論解析よる異材接合の局所変形モデルの構築を行っている．その解析モデルは今後のシミュレーション予測を始め，わが国が推進しているマテリアルDXなどのAI，ビックデータ，インフォマティックスなどのデータ駆動研究にも適用ができるものと考えている．そのため本研究は工業的展開が可能な学術研究として役に立つものと思われる．