Spark plug, used to initiate gas e.g. air/fuel mixture in internal combustion engine, comprises metallic shell, insulator, and center and ground electrodes that include electrode material including ruthenium, rhenium and tungsten

摘要

The spark plug comprises a metallic shell (16) having an axial bore, an insulator (14) that has an axial bore and is partially disposed within the axial bore of the metallic shell, a center electrode (12) that is partially disposed within the axial bore of the insulator, and a ground electrode (18) attached to the shell. The center electrode and ground electrode include an electrode material having 1-40 wt.% of ruthenium (Ru) and 0.1-10 wt.% of rhenium (Re) and tungsten (W). A ratio of Re to W is 1:1. The electrode material further includes precious and rare earth metals. The spark plug comprises a metallic shell (16) having an axial bore, an insulator (14) that has an axial bore and is partially disposed within the axial bore of the metallic shell, a center electrode (12) that is partially disposed within the axial bore of the insulator, and a ground electrode (18) attached to the metallic shell. The center electrode and ground electrode include an electrode material having 1-40 wt.% of ruthenium (Ru) and 0.1-10 wt.% of rhenium (Re) and tungsten (W). A ratio of Re to W is 1:1. The electrode material further includes precious and rare earth metals. The Ru is the single largest constituent of the electrode material on a weight percentage basis, the precious metal is the second largest constituent of the electrode material on the weight percentage basis, and the Re or W is the third largest constituent of the electrode material on the weight percentage basis.