河端　征大KAWABATA Masahiroカワバタ　マサヒロ

業績情報

氏名・連絡先

• 氏名

  カワバタ　マサヒロ, 河端　征大, KAWABATA Masahiro

主たる所属・職名

• 工学研究院　機械システム工学部門, 助教

学位

• 博士（工学）
  東京農工大学
  2024年09月

科学研究費助成事業

• 研究活動スタート支援
  ワイヤアークAMにおけるパルス溶接を活用した造形高さ制御システムの開発
  自 2025年, 至 2026年

論文

• Influence of electrode rotation speed on geometry and internal structure of weld beads in rotary TIG wire-arc-directed energy deposition
  Bimbi, Andrea; Kawabata, Masahiro; Tsunekawa, Togen; Sasahara, Hiroyuki; Campatelli, Gianni
  INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
  SPRINGER LONDON LTD
  This study investigates the effects of varying the electrode rotational speed in rotary tungsten inert gas (rotary TIG), a novel wire arc additive manufacturing technology. Rotary TIG aims to mitigate the directional nature of the TIG WAAM process, producing weld beads with uniform cross-sections conducive to additive manufacturing. Scripts were developed to analyze the characteristics of deposited single bead profiles. The results demonstrate that increasing the electrode rotational speed leads to increased height at the expense of the width in the weld bead profiles. Additionally, rotary TIG weld bead profiles exhibit a parabolic shape and a geometry forecast model was developed. The effect of electrode rotation speed has been magnified; a metallurgical analysis reveals that the internal structure loses its uniformity as the rotational speed decreases. Furthermore, a thermofluidic dynamic simulation was developed to replicate the rotary TIG welding process. This simulation confirms that electrode rotation speed impacts geometry, aligning with experimental findings.
  2024年12月, 研究論文（学術雑誌）, 共同, 135, 9-10, 0268-3768, DOI(公開)(r-map), 4401, 4420
• Welding torch with coaxial wire feed and rotating electrode for wire-arc directed energy deposition
  Kawabata, Masahiro; Sasaki, Tomoaki; Wada, Katsunori; Kanemaru, Shuhei; Nomura, Yuji; Sasahara, Hiroyuki
  ADDITIVE MANUFACTURING
  ELSEVIER
  In wire-arc directed energy deposition (DED), tungsten inert gas (TIG) welding/gas tungsten arc welding (GTAW), which offers high flexibility in deposition conditions and less spatter, are used as primary welding processes. However, in additive manufacturing of complex shapes with TIG welding, it is difficult to achieve uniform and stable fabrication because the wire is fed from a fixed lateral direction to the centered arc heat source. To overcome this problem, a novel rotary TIG torch was developed in this study. The wire was fed from the center of the torch, and the tilted electrode or arc heat source rotated around the wire during deposition, allowing the deposition process to be omnidirectional. In the experiment, the basic characteristics and process window of the rotary TIG were investigated, and single-layer and multilayer depositions were performed with changing torch travel directions to evaluate deposition accuracy and flexibility. In conventional TIG, particularly under the condition of low heat input per material input, the deposited bead position and shape were changed depending on the travel direction, and in multilayer deposition, up to 1 mm deviation of the deposition position was observed. In contrast, in the rotary TIG, beads were deposited uniformly regardless of the travel direction and deposition conditions, and in multilayer deposition, straight walls were obtained, and the deviation in the deposition position was small. The results suggest that the application of the rotary TIG torch to wire-arc DED can achieve highly accurate fabrication with higher flexibility in building conditions.
  2024年03月25日, 研究論文（学術雑誌）, 共同, 84, 2214-8604, DOI(公開)(r-map)
• Effect of arc length on deposition characteristics in rotary tungsten inert gas (TIG) torch
  Kawabata, Masahiro; Sasaki, Tomoaki; Wada, Katsunori; Kanemaru, Shuhei; Nomura, Yuji; Sasahara, Hiroyuki
  JOURNAL OF ADVANCED MECHANICAL DESIGN SYSTEMS AND MANUFACTURING
  JAPAN SOC MECHANICAL ENGINEERS
  A rotary tungsten inert gas (TIG) torch has been developed to enhance the quality and complexity of fabrications in wire and arc additive manufacturing (WAAM). This study explores the influence of arc length on deposition characteristics within a rotary TIG torch by adjusting the wire feed speed, travel speed, and shielding gas type. The findings reveal that the unique vertical wire feeding mechanism of the rotary TIG torch prevents the wirefeeding position shift typically observed in conventional TIG processes. However, extended arc lengths in the rotary TIG setup tend to induce arc deflection and molten metal scattering due to the employment of a tilted electrode. Specifically, at high wire feed and travel speeds, bead continuity is compromised by molten metal scattering. Conversely, at low travel speeds relative to wire feed speeds, defect -free deposition is achievable across a broad arc length spectrum from 4 to 20 mm using rotary TIG. Furthermore, decreasing the wire feed speed in proportion to the current and increasing the heat input per material input minimizes the contact time between the wire and the molten pool, thus mitigating arc deflection. Employing helium -mixed gas as a shielding gas facilitates defect -free deposition over an extensive range of arc lengths, even under conditions that typically induce humping with pure argon.
  2024年, 研究論文（学術雑誌）, 共同, 18, 4, 1881-3054, DOI(公開)(r-map)

受賞

• 公益社団法人 精密工学会　ICPE2024
  ICPE2024 Excellent Paper Award
  "Development of deposition height control system for GTAW-based additive manufacturing”
  ICPE2024（The 20th International Conference on Precision Engineering）において、優れた論文の著者に授与される。
  2024年10月26日
• 一般社団法人 溶接学会 溶接法研究委員会
  溶接学会 溶接法研究委員会 溶接物理・技術奨励賞
  「回転TIGトーチの精度と能率に関する調査とWAAMへの適⽤検討」
  溶接プロセス・溶接アーク物理に関する研究・技術開発分野において、今後、溶接学会の発展に大きく貢献することが期待できる研究報告に授与される。
  2025年08月07日