| 摘要 |
A method of manufacturing a contact bridge for an electric switching apparatus which contact bridge includes an electrically highly conductive overlay and a concave-shaped support layer. The method comprises the steps of pressing a powder blank comprising two layers of metallic material, one of which comprises iron for the support layer and the other of which comprises copper for the overlay; sintering the blank in a protective gas; sizing the blank; further sintering the blank in a protective gas; further pressing the blank by reverse-flow cup extrusion; and applying an electrical contact to the overlay. Alternatively, the powder blank may comprise a layer of copper-zirconium and silver-metal oxide, the latter for an electrical contact layer. In this embodiment, the contact bridge is formed with the electrical contact in one step and there is no need to apply a contact to the bridge after the pressing by reverse-flow cup extrusion. |
