Patent ID: 6756122
Filing Date: 2004-06-29
Classification: C04B,C23C,Y10S,Y10T

Abstract:
A porous substrate having an adherent, substantially uniform elemental boron-coated surface prepared by the steps of: (a) immersing a porous substrate in a liquid hydrocarbon; (b) while said substrate is immersed in said liquid hydrocarbon, heating the substrate so as to establish a temperature gradient through the substrate whereby at least the interior of the substrate is heated to a temperature above the decomposition temperature of the hydrocarbon while maintaining a lower temperature at the surface of the substrate, for a period sufficient to at least partially densify the surface of the substrate to reduce surface porosity, while maintaining adequate roughness in the surface of the substrate to promote mechanical locking with a subsequently applied coating consisting essentially of pure elemental boron; and (c) coating the at least partially densified substrate surface with a coating consisting essentially of pure elemental boron by chemical vapor deposition.