Study on the formation mechanism of dissimilar joint interfaces in the disc friction joining

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04773
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: University of Toyama
• Principal Investigator: Shibayanagi Toshiya 富山大学, 学術研究部都市デザイン学系, 教授 (10187411)
• Co-Investigator(Kenkyū-buntansha): 山根 岳志 富山大学, 学術研究部都市デザイン学系, 助教 (60272895)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 円盤摩擦接合 / アルミニウム / 樹脂 / チタン / マグネシウム / 円盤表面性状 / 引張強度 / 界面構造

Outline of Final Research Achievements

Disc Friction Joining (DFJ)is a novel joining method which was invented in Toyama, Japan. The present research project has tried both similar joining of aluminum to aluminum and dissimilar joining of aluminum to resin, magnesium, and titanium. These joining tests successfully produced joints that showed a peculiar interface of zig-zag shape. The zig-zag interface may lead us to a new welding technology called “reverse welding” just like a zipper. Fine grain structure was observed in the region closed to the joint interface, which seemed to be produced by the dynamic recrystallization during joining. Tensile tests for Al/PET joint at ambient temperature revealed the joint efficiency was around 40% to the strength of resin. The DFJ interface is concluded to be produced around periphery of the rotating disc where the materials were about to be joined.

Free Research Field

接合科学

Academic Significance and Societal Importance of the Research Achievements

円盤摩擦接合は、世界発の接合技術で、日本でこの原理が提案され、実証実験を経て、一定の水準の継手強度が得られることが明らかにされたことが本研究成果の最大のポイントである。界面構造は本接合法特有の凹凸構造となっており、ファスナーのような構造であることから可逆接合技術の端緒を開く基礎知見としての学術的・技術的意義は大きい。また、アルミニウムとチタンといった融点が1000℃ほど異なる材料の接合にも成功したことは従来の溶接技術の範疇を凌駕する技術への展開が期待できる。本接合技術は原理的には無限長の接合が可能で、またアーク溶接のようなガスを必要とせず、環境負荷を最小にする接合としての社会的意義は大きい。