Detection of stir zone and elucidation of bonding mechanism in friction stir diffusion bonding of dissimilar metallic foils

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06814
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Composite materials/Surface and interface engineering
• Research Institution: Utsunomiya University
• Principal Investigator: Takayama Yoshimasa 宇都宮大学, 工学部, 教授 (60163325)
• Co-Investigator(Kenkyū-buntansha): 山本 篤史郎 宇都宮大学, 工学部, 准教授 (40334049)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 摩擦撹拌接合 / 摩擦撹拌拡散接合 / 箔 / アルミニウム / チタン / EBSD解析

Outline of Final Research Achievements

Friction stir diffusion bonding (FSDB) has been applied to lap foil joints of A5052, A4045 or A1050 aluminum alloy on top of commercial purity (CP) titanium. FSDB of the foils was successfully performed through stirring only the upper aluminum foil by the air spindle with an extremely-high rotation speed of 105,000 rpm. In the spot FSDB, bonding strength varied with a distance from the tool center. In order to investigate the stir zone and the stirring mechanism of the upper foil, EBSD analysis was performed on the cross-section of the joint. As a result, two characteristic regions were observed, the former has fine grains while the latter has coarse. The distribution of these regions corresponded to the joint strength distribution.

Free Research Field

材料工学

Academic Significance and Societal Importance of the Research Achievements

工業用純チタン箔の上にA5052, A4045およびA1050アルミニウム合金箔を重ね、回転するツールを箔材に押付け材料を加熱するとともに撹拌する摩擦撹拌拡散接合(FSDB)を行った。通例板材に適用されるFSDBを0.1mm厚の箔材に適用し、超高速回転するエアスピンドルを用いることにより首尾よく接合された。これまで不明であった撹拌領域と接合機構を接合断面のEBSD結晶方位解析により明らかにした。また、高い接合強度が大きなひずみに対応する微細粒領域で得られることが分かった。