Palladium belongs to the platinum group of metals and like platinum is highly resistant to atmospheric corrosion; however, it begins to tarnish at temperatures above 400°C. It has a high melting point (1552(C) and, like platinum, resists arc formation. Its low electrical conductivity (16% IACS) limits its application to low current circuits. It costs much less than platinum, and is used as a lower cost alternative. Economics normally dictate that it be supplied as a composite contact with a thin contact metal facing silver brazed to a nickel-plated steel rivet, screw, or projection weld button backing. ELKONIUM® 40 is CMW's trademark for commercially pure palladium (9.90 minimum purity). Its good corrosion resistance and low hardness makes it a desirable contact for low current applications where forces are relatively low and reliability of making circuit is important. It is used in aircraft relays at currents under 1 ampere, in telephone relays and in instruments. It is often chosen for applications where contacts area open for long periods of time. Information provided by NAECO, LLC. |