Thin metal casing or sleeve in nickel-cobalt alloy, used on heated rollers for printing and copying, is electroplated onto chromium-plated steel roller in presence of ultrasound

摘要

The thin metal casing is electroplated onto a hard chromium-plated steel roller, under the effects of ultrasound, which promotes columnar nickel growth. The casing comprises a nickel alloy containing 95-98% nickel and 1-4.9% cobalt. The nickel alloy contains 0.05-0.3% of zirconium. The total cobalt and zirconium content of the alloy is 1-4.9%. The casing has a nickel hardness of 450-500 VH (Vickers hardness) and a modulus of elasticity of 1350-1450 N/mm2. Wall thickness of the casing is 40-60 mu m. The electrolytic bath contains: nickel sulfate 280-320 g/l, cobalt sulfate 2.5-5 g/l, boric acid 25-30 g/l and saccharin 0.3-0.5 g/l. On or in the main body, an ultrasonic generator promotes the predominantly-columnar nickel growth. The bath temperature is 48-52[deg] C and the pH value is 4.3-4.5. The current density in the bath is 4-8 A/dm3 (sic). The main body is coupled to a rotary drive giving it a speed of 1-10 rpm in the bath. An independent claim IS INCLUDED FOR the method of manufacturing the casing.