NICKEL-PLATED TITANIUM WIRE OR NICKEL-PLATED TITANIUM ALLOY WIRE AND PRODUCTION THEREOF

摘要

PURPOSE: To improve adhesive strength and workability of plating by electrolysis-pretreating a titanium-based metallic wire with hydrochloric acid or a mixed acid of hydrochloric acid and nitric acid or sulfuric acid and electro- nickelplating the metallic wire by the use of a nickel sulfaminate solution. ;CONSTITUTION: A titanium wire or titanium alloy wire is electrolysis-pretreated with only hydrochloric acid or the mixed acid of hydrochloric acid and nitric acid or sulfuric acid and the surface of the titanium-based metallic wire is made to a state that a passive state film is not completely removed. After that, the surface is electro-nickel plated by the use of the nickel sufaminate bath adjusted to pH2.0-4.0. As a result, a plating layer small in internal stress and high in adhesive strength is formed without using hydrofluoric acid and without generating ruggedness, and the titanium-based metallic wire requiring the surface smoothness for spring or the like and excellent in workability is obtained.;COPYRIGHT: (C)1993,JPO&Japio