| 摘要 |
Process for depositing an adherent nickel, copper or cobalt coating on a component made of oxidisable or passivated metal, especially of tantalum. This process includes the following stages: a) subjecting the component to a surface treatment, for example an ultrasonic degreasing followed by sandblasting, to remove the oxide film formed on the oxidisable metal or alloy; b) next, depositing a first thin layer of coating metal by electrolysis on the surface thus treated, by employing a first electrolysis bath containing a chloride of the coating metal and hydrofluoric acid or an acidic fluoride such as NH4F, HF; and c) next, depositing a thicker second layer of the coating metal by electrolysis, by employing a second electrolysis bath containing a salt of the coating metal such as a Watt bath. The fact of producing the deposit by two-stage electrolysis including a first stage in the presence of HF makes it possible to obtain very good adhesiveness without any additional heat treatment.
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