Surface treatment of aluminum wire

摘要

Aluminum has replaced other materials, such as copper, in various applications. Electrical industry is particularly concerned since the weight, the power and the price of the equipments are frequently important factors, for which aluminum offers a good solution and a low cost. Used for example in flexible cables for aeronautical engineering or in enamelled wire for electrical windings, the aluminum wire often requires specific surface preparations. That is why the three following processes have been specially designed for this product: · direct nickel-plating has been developed to give a low and stable contact resistance coupled with a very good adhesion of the nickel deposit, · pre-enamelling treatment has been designed to enhance adhesive properties of insulating varnishes. These processes have been commercially used for several years. · electrically-conducting passivation is a new and innovative surface treatment, ensuring stable contact resistance together with a good corrosion resistance. Main properties of the treated wire will be detailed and some examples of industrial applications will be provided.