Boron carbide-based coatings on graphite for plasma facing components
In the effort to evaluate boron-rich coatings as plasma facing surfaces in fusion devices, a new process for applying boron carbide (B(4)C) coatings to graphite was developed. The process entails eutectic melting of the carbon (C) substrate surface with a precursor layer of B(4)C particles. Adherent coatings were achieved which consisted of two layers: a surface layer and a graded penetration zone in the outer portion of the substrate. The surface-layer microstructure was multiphase and ranged from reaction-sintered structures of sintered B(4)C particles in an eutectic-formed matrix to that of hypereutectic carbon particles in a B(4)C-C eutectic matrix. Because of high surface energy, the coating generally developed a non-uniform thickness. Test results revealed good adherence of the coating even after remelting; during remelting, diagnostics detected a corresponding interaction of boron with the plasma.
Bibliographic Reference: Report: GA-A21295 EN (1994) 19 pp.
Availability: Available from Zentralbibliothek der Forschungszentrum Jülich GmbH, Postfach 1913, 5170 Jülich (DE)
Record Number: 199411447 / Last updated on: 1994-12-06
Original language: en
Available languages: en