Spark plug electrode tip for internal combustion engine
 A spark plug electrode wire composed of an iridium-rhodium alloy exhibits improved erosion resistance and enhanced durability in leaded and unleaded fuel environments. The alloy is formed into a wire having high thermal conductivity, low electrical resistivity, good oxidation resistance, good corrosion resistance, good wear resistance. It exhibits desirable work function in pure metals and alloys such as iridium and iridium-rhodium. The wire is inserted into the center electrode of the spark plug and brazed to an Inconel base metal and copper core thereof using a silver-based brazing alloy. After electrical engine dynamometer testing for 200 hours, an improvement in erosion resistance as high as eight fold was observed with an 60% iridium-40% rhodium alloy, when compared to a conventional 90% platinum-10% nickel alloy. The iridium-rhodium spark plug electrode wire can be used to minimize erosion and wear resistance in leaded and unleaded fuel environments. 
AlliedSignal Inc.
H
H01T
inventional
Edgar Arnold Richard Dale Chin-Fong Michael Sean
Leone Taylor Chang Zedalis