Sealing the surface of porous metal and - refractory overlaps

摘要

Porous metal or refractory overlays applied to a substrate by the flame-, electro-, powder-, or plasma spray process are given improved adherence and corrosion resistance by sealing the surface with a metallic layer, the metal being from group VIII, by electroless plating using a metal salt soln. contg. a reducing agent such as Ni compds. with Na hypophosphite, or with N-diethylborazane or Na boranate, or Cu compds. with formaldehyde.