Highly Efficient Surface Smoothing by Clarification of EB Polishing Mechanism with Considering Flow of Material

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03807
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Okayama University
• Principal Investigator: Shinonaga Togo 岡山大学, 環境生命自然科学学域, 助教 (60748507)
• Co-Investigator(Kenkyū-buntansha): 岡本 康寛 岡山大学, 自然科学学域, 准教授 (40304331)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 大面積電子ビーム / EBポリッシング / 表面平滑化 / 表面粗さ / 熱流体解析 / 溶融金属 / 表面張力 / 微細凹凸形状

Outline of Final Research Achievements

In large-area electron beam (EB) irradiation, metal surface can be melted instantly and uniformly by the EB irradiation with high energy density. Then, metal mold surface with surface roughness of several μmRz can be reduced to less than 1.0 μmRz, and surface finishing of metal molds can be done efficiently by EB polishing. However, mechanism of the EB polishing has not been clarified yet. It is expected that EB is concentrated on small convex parts of metal surface and molten metal is flowed into concave parts. In this study, EB polishing mechanism was clarified by thermo-fluid analysis. EB concentration phenomena on convex parts were also investigated by electro-magnetic field analysis. In addition, highly efficient surface smoothing of metal products with large surface roughness was proposed.

Free Research Field

特殊加工学

Academic Significance and Societal Importance of the Research Achievements

金属製品は用途に応じて表面仕上げが必要である．これまでの研究で，大面積電子ビーム照射法を用いたEBポリッシングによって，鉄鋼系金型などを高能率に表面平滑化することができることを明らかにしてきた．しかしながら，EBポリッシングメカニズムについては未解明であった．本研究で構築した熱流体解析により，電子ビーム照射による溶融金属の流動や表面形状変化の過程などを見出すことができた．研究成果は，様々な実用材料や加工面に対して，EBポリッシングにより高能率な表面仕上げを実現するために有用であると考えられる．さらに，大面積電子ビーム照射によるフィレット加工など，様々な加工現象の解明にも有効である可能性がある．