Relationship during Micro Texture, Strength and Formability of Aluminum Alloy/Steel Laser Butt Tailored Welded Blanks

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05153
• 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: Kyoto Institute of Technology
• Principal Investigator: Takashi Iizuka 京都工芸繊維大学, 機械工学系, 教授 (60335312)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 塑性加工 / 板材成形 / テーラードブランク / 異種金属接合 / レーザ接合 / 成形性 / 耐電界腐食性

Outline of Final Research Achievements

Aluminum alloy/steel tailor welded blanks(TWBs) is expected as future light-weighing materials. In this study, aluminum alloy/steel TWBs were fabricated using laser butt welding in order (1) to improve joint strength, (2) to evaluate sheet formability of them, and (3) to clarify resistance to galvanic corrosion. As for the aim (1), strength maps related to welding conditions and joint strength were created. In addition, correlation maps during welding conditions, joint strength and texture were also created. As for the aim (2), punch stretching tests and hole expansion test were conducted to TWBs, and relationships between joint strength and sheet formability were clarified. As for the aim (3), the combined cycle corrosion tests were conducted to TWBs. From the results, resistance to galvanic corrosion for each TWBs could be evaluated and some differences in degradation behavior of joint strength by welding methods were clarified.

Free Research Field

機械工学

Academic Significance and Societal Importance of the Research Achievements

異種金属テーラードブランクは将来的な軽量化材料として期待されているが，アルミニウム合金/鋼の系についてレーザ接合を用いた研究はほとんど行われていない．本研究で得られた成果は強度向上，成形性および耐電界腐食性に関するものであるが，まず接合法自体が新しいため得られた成果は全て学術的に試金石的なものとなると考えられる．特に成形性や耐腐食性に関しては，他の接合法も含めて新しいものであり，今後の二酸化炭素排出削減のための異種金属接合材の開発と利用の促進のために重要であり，社会的な意義も大きいと考えている．現状では課題が浮き彫りになった状況であるが，課題克服のヒントも得ることができたことは重要である．