IE35274L - Electroplating abrasive particles with metal - Google Patents

Abstract

1304964 Electro-plating abrasive particles DE BEERS INDUSTRIAL DIAMOND DIVISION Ltd 21 May 1971 [22 May 1970] 16292/71 Heading C7B Abrasive particles, e.g. of diamond, cubic BN, SiC or WC, are metal coated, e.g. with Fe, Ni, Co, Cr, Pb or alloys thereof, by placing the particles, rendered conductive e.g. by electroless plating of Ni or Co as described in Specification 1198479, in a plating solution of the metal sulphamate, applying a PD across the solution and recovering the discrete metal-coated particles from the solution. The solution preferably contains chloride ions e. g. of the metal or Na to activate the anode, and anti-pitting and stress relieving agents. Plating may be effected in a rotary barrel having a series of Ti cathodes on its inner surface. A solution is specified containing nickel sulphamate and chloride with boric acid for obtaining bright Ni of density greater than 8À0 g/cc; the Ni coating may be electro-plated with Cu. Fe/Ni alloys may be electro-plated from a solution containing iron, nickel and ammonium sulphamates with boric acid and ammonium chloride. [GB1304964A]