|
6432 |
|
Iron-Carbon nanotube composite film fabricated by low-pressure cold spray method
|
|
Wataru Nakayama / Tokyo Institute of Technology, Japan Jongbeom Choi/ Tokyo Institute of Technology, Japan Nana Okimura/ Tokyo Institute of Technology, Japan Yuki Hirata/ Tokyo Institute of Technology, Japan Naoto Ohtake/ Tokyo Institute of Technology, Japan Hiroki Akasaka/ Tokyo Institute of Technology, Japan |
|
Iron and their compounds including the steel are important industrial material which is used in varieties of fields. Steel is one of the iron-carbon compounds, have mechanical property varies by the concentration of the carbon atoms. Carbon atoms can be introduced as a solid solution or a form of carbide. Usually, hardness increases accompanied with the increase in carbon content. On the other hands, control of the carbon distribution in the interior of the steel is difficult. Carbon nanotubes (CNTs) have used as a functional material of composite material. Since it is oxidized in high temperature, it was difficult to apply high temperature process such as production of metal matrix composite. In this study, the cold spray (CS) method was used to fabricate iron-CNT composite films. It is a method to form thick films from solid particles by plastic deformation, and source material experiences temperature lower than its melting point. Since it requires low process temperature, it is suitable to use materials with low decomposition temperature. The introduced CNTs in iron were used as a carbon source and diffusion of the carbon atoms into iron was attempted by heating composite material. Iron-CNT composite film was fabricated on the substrate from powder mixture of pure iron and CNTs by low-pressure CS method. Containing of CNTs in the deposited composite materials was confirmed by observing graphitic and disorder bands in Raman spectra. Films were annealed at 550 under a vacuum condition graphitic and disorder bands disappeared at spectra after the heat treatment. Moreover, indentation test was conducted and hardness of iron-CNT composite film increased after the heat treatment. These results suggest that the carbon atoms diffused into the iron coating. |