CPC Subgroup
C23C 22/64 Treatment of refractory metals or alloys based thereon
Full Title
Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals > using aqueous solutions > using alkaline aqueous solutions with pH greater than 8 > Treatment of refractory metals or alloys based thereon