Basic and Applied Study on Metal Treatment with Atmospheric-Pressure Plasmas for Contributing Manufacturing and Medical Fields

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17482
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Plasma electronics
• Research Institution: Oita University
• Principal Investigator: Ichiki Ryuta 大分大学, 理工学部, 助教 (00454439)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 大気圧プラズマ / 窒化処理 / NHラジカル / 表面硬化 / 生体適合性 / 酸化皮膜 / マルテンサイト変態

Outline of Final Research Achievements

Before the progress of this project, we shared no knowledge on nitriding with atmospheric-pressure plasma. This project has provided the following basic knowledge and techniques to us.
Basic: NH radical is the key radical in the atmospheric-pressure plasma jet nitriding. The control method of nitrogen into metal surface is established. The dielectric barrier discharge is also available for nitriding. The planar barrier discharge shows peculiar behaviors under high temperature that the ignition area is expanded beyond the area of opposite electrode and the filamentary appearance of discharge becomes glow-like.
Technical: Biocompatibility of titanium for medical use is upgraded by plasma-jet nitriding. Stainless steels with oxide film can be nitrided through the reduction of film by hydrogen. Void formation in nitro-quenching can be suppressed by decreasing the production of NH radicals. These achievements established the scientific value of the atmospheric-pressure plasma nitriding.

Free Research Field

プラズマ科学