Establishment of high-speed and high-strength dissimilar joining technology for light-metal materials by forge welding

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K05110
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26030:Composite materials and interfaces-related
• Research Institution: Toyama Industrial Technology Research and Development Center
• Principal Investigator: Yamagishi Hideki 富山県産業技術研究開発センター, その他部局等, 副主幹研究員 (50416153)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 固相接合 / 異材接合 / 低温鍛接 / 界面 / 金属間化合物 / アルミニウム

Outline of Final Research Achievements

Solid-phase dissimilar-material joining technology for metallic materials using a press machine was developed. By introducing large deformation to the bonding area, the diffusion barrier such as oxide film is broken up and stretched to create a high cleanliness interface, realizing low temperature and short time diffusion. This invented method is "Cold forge welding," a virtually IMC-free, high-speed, high-strength solid-phase bonding method that can suppress reaction layer.
This process was demonstrated with aluminum as the core and in various combinations with steel, copper, and other materials. The tensile strength of each phase at the bonded interface created by this method was calculated using the newly proposed specimen preparation method and the composite material strength law. It was also clarified that the growth behavior of the reaction layer can be controlled by the bonding temperature and the thickness ratio (reduction ratio) before and after bonding.

Free Research Field

溶接・接合

Academic Significance and Societal Importance of the Research Achievements

従来の各種固相異材接合法が抱えている実用上の様々な問題(プロセス時間、生産コスト、接合強度等)を根本的に解決しうる革新的な高速・高強度固相接合技術を開発し、特許を権利化した。車両の軽量化及び電動化が進むモビリティ向けに当該法の実装が強く期待されるだけでなく、熱間の塑性流動を伴う拡散反応において、変形量を増すほどより低温での接合が可能になるなどの本法の特徴及び新たな接合機構を示したことは、拡散ベースの固相接合プロセスの発展に寄与するものと考えられる。