| Platinum has complete freedom from atmospheric corrosion and is preferred for devices that have low closed forces and where surety of making a circuit may be a problem. It has a high melting point (1769(C) and good resistance to forming arcs. Low electrical conductivity (15% IACS) limits its application to low currents, usually below 5 amperes. Because of the high cost of the platinum ELKONIUM alloys, they are almost always supplied as composite contacts with thin facings of the ELKONIUM metal (silver brazed to nickel plated steel backings in the form of rivets, screws and weld buttons). ELKONIUM® 302 is the trademark used by CMW for an alloy of platinum, palladium and ruthenium. It has characteristics similar to ELKONIUM 34 alloy. It is more economical than platinum-ruthenium alloys because the less expensive palladium metal replaces some of the platinum. Its tarnish resistance is essentially the same as CMW's ELKONIUM 34 alloy. It is used in sensitive low voltage applications. It is also used as a positive contact operating with a tungsten negative contact in DC applications such as voltage regulators and motor speed governors Information provided by NAECO, LLC. |
