| 摘要 |
<p>Contact surfaces are coated with at least 2 successive layers, of which one is 0.04-10 mu thick and consists of carbon, graphite, P, S, Si, Al, Pb, Zn, Cd, Bi or a metal oxide. The other is 0.3-20 mu thick and consists of one or more other metals and possible a hardening agent. Pref. the second layer consists of precious metal. The contacts are used in telephone computer and data transmission systems.</p> |
