COMBUSTION INITIATORS EMPLOYING REDUCED WORK FUNCTION ELECTRODES

摘要

The electron emitting cathode of an initiator (24) (spark plug or ignitor) comprises a small button (26) of high temperature, preferably austenitic, stainless steel powder welded to a support conductor (28). The stainless steel powder has distributed through it a dopant powder consisting of a minor portion of a highly stable oxide of an element having a low work function. The dopant powder has a much smaller mesh size than the stainless steel powder (1/5 or less). Rare earth lanthanides are preferred that have a low work function, preferably under 3.0eV and are not radioactive. Cerium, in the form of CeO2 is most preferred. The compositions of the low work function stainless steel electrodes and methods of making the same are disclosed.