Aluminium silvering of high current connectors using printing techniques and nanopowders

Aluminium busbar connectors provide high current connections between metal connectors and are widely used in electrical power industry. They are formed by clamping two or more plates of flat aluminium with the use of bolts and nuts. Plain aluminium tends to form oxide, which is known of it´s very high resistivity To avoid that effect, a surface of aluminium can be electroplated with silver. The main drawback of this method is a toxic waste production. Another problem is the possibility to repair it in outdoor conditions Due to high surface energy of nano-particles, sintering of layers occurs in temperatures much below silver melting point (961°C), and which is more important below melting point of aluminium (660°C). Pastes containing nanosize silver powders were prepared. They were screen printed on etched aluminium plates and cured in several temperatures varying from 300 to 500°C. The plates were pressed towards, forming contact joint that simulates the bolted connection. The contact resistivity versus pressure was tested.