BibTeX:

@article{IJIRSTV4I9036,
     title={Enhancement of Insulation Properties of RAFM Steel Surface by Development of Thin Film Coating of Aluminium Oxide by Laser Technique},
     author={S. P. Chakraborty, N. K. Chakraborty and Madan Gopal Krishnan},
     journal={International Journal for Innovative Research in Science & Technology},
     volume={4},
     number={9},
     pages={107--114},
     year={},
     url={http://www.ijirst.org/articles/IJIRSTV4I9036.pdf},
     publisher={IJIRST (International Journal for Innovative Research in Science & Technology)},
}

Reduced activation Ferritic/Martensitic steel (RAFMS) is a potential candidate material for structural applications specially as coolant channels in the Indian Test Blanket Module System (TBM) for International Thermonuclear Experimental Reactor (ITER). In order to prevent any pressure drop effect during the flow of metallic coolant of Pb-Li liquid through the RAFMS cooling channels due to magneto-hydrodynamic effect (MHD), surface coating with high electrical insulating properties is required prior to use. Hence, in the present study, investigations were carried out to develop coating of alumina (Al2O3) on RAFM steel substrate by pulse laser deposition (PLD) technique as alumina has unique properties of high electrical insulation properties. Moreover, by laser technique, it was possible to obtain defect free surface with impervious layer of thin film coating of alumina which is responsible to render high electrical insulation property. Laser pulse transformed the meta-stable Al-O (γ) phase present in the alumina target into thermodynamically stable Al-O (α) phase in the coating. Maximum coating thickness of 2 µm was achieved having uniform and defect free surface. High electrical insulation property in terms of electrical resistivity was achieved (electrical resistivity value: 2.14 x 106 ohm.cm). The alumina coating further showed very high hardness of value of 400 VHN and high adhesive strength of the order of 15 MPa.

Laser, Deposition, Alumina, Coating, RAFMS, Characterization