An
electrode for an ignition device is made from a Ni-based
nickel-
chromium-iron
alloy which has improved resistance to high temperature oxidation,
sulfidation, corrosive wear, deformation and fracture includes, by weight of the
alloy: 14.5-25%
chromium; 7-22% iron; 0.2-0.5%
manganese; 0.2-0.5%
silicon; 0.1-2.5% aluminum; 0.05-0.15%
titanium; 0.01-0.1% total of
calcium and
magnesium; 0.005-0.5%
zirconium; 0.001-0.01%
boron, and the balance substantially Ni. It may also include at least one
rare earth element selected from the group consisting of:
yttrium,
hafnium,
lanthanum,
cerium and
neodymium in amounts
ranging from 0.01-0.15% by weight, and incidental impurities, including
cobalt,
niobium,
molybdenum,
copper, carbon, lead,
phosphorus or
sulfur. These total of these impurities will typically be controlled to limits of 0.1%
cobalt, 0.05%
niobium, 0.05%
molybdenum, 0.01%
copper, 0.01% carbon, 0.005% lead, 0.005%
phosphorus and 0.005%
sulfur. The ignition device may be a
spark plug which includes a
ceramic insulator, a conductive shell, a center
electrode disposed in the
ceramic insulator having a terminal end and a sparking end with a center
electrode sparking surface, and a ground electrode operatively attached to said shell having a ground electrode sparking surface, the center electrode sparking surface and the ground electrode sparking surface defining a
spark gap therebetween. At least one of the center electrode or the ground electrode includes the solution-strengthened Ni-based
nickel-
chromium-iron
alloy. The Ni-based
nickel-chromium-iron alloy electrodes of the invention may also include a core with
thermal conductivity greater than that of the Ni-based nickel-chromium-iron alloy, such as
copper or silver or their alloys.