Ignition Device Electrode Composition

Abstract

An ignition device includes a ground electrode, center electrode, or both composed of a cobalt-based alloy including: Ni in an amount between about 20 and 24% by weight; Cr in an amount between about 20 and 24% by weight; W in an amount between about 10 and 16% by weight; and Co in an amount between about 32 and 47% by weight or alternately an iron-based alloy comprising: Cr in an amount between about 18 and 24% by weight; Al in an amount between about 4 and 7% by weight; and Fe in an amount between about 67 and 78% by weight. It is believed that the electrode alloys may also include Zr and B in an amount, by weight, of 0.005-0.5% Zr and 0.001-0.10% B. Center or ground electrodes of the invention may also include firing tips attached at a sparking end thereof. The firing tips may be formed of at least one of gold, a gold alloy, a platinum group metal or a tungsten alloy.

1 . An ignition device comprising an electrode composed of a cobalt-based alloy, comprising:
 Ni in an amount between about 20 and 24% by weight; Cr in an amount between about 20 and 24% by weight;   W in an amount between about 10 and 16% by weight; and Co in an amount between about 32 and 47% by weight.   
     
     
         2 . The ignition device as defined in  claim 1 , wherein said alloy more specifically comprises:
 W in an amount of about 13% by weight.   
     
     
         3 . The ignition device as defined in  claim 1 , further comprising a firing tip attached to said electrode. 
     
     
         4 . An ignition device comprising an electrode composed of an iron-based alloy comprising:
 Cr in an amount between about 18 and 24% by weight;   Al in an amount between about 4 and 7% by weight; and   Fe in an amount between about 67 and 78% by weight.   
     
     
         5 . The ignition device as defined in  claim 4  wherein said alloy more specifically comprises:
 Cr in an amount between about 19 and 21% by weight;   Al in an amount between about 4.5 and 5.25% by weight; and Fe in an amount between about 72 and 77% by weight.   
     
     
         6 . The ignition device as defined in  claim 5  wherein said alloy further comprises:
 Zr in an amount between about 0 and 0.3% by weight; C in an amount between about 0 and 0.08% by weight;   Mn in an amount between about 0 and 0.5% by weight; and Si in an amount between about 0 and 0.6% by weight.   
     
     
         7 . The ignition device as defined in  claim 4  wherein said alloy more specifically comprises:
 Cr in an amount between about 19 and 21% by weight;   Al in an amount between about 4.5 and 5.5% by weight; and Fe in an amount between about 72 and 77% by weight.   
     
     
         8 . The ignition device as defined in  claim 7  wherein said alloy further comprises:
 Ni in an amount between about 0 and 0.3% by weight;   Ti in an amount between about 0 and 0.1% by weight;   N in an amount between about 0 and 0.02% by weight;   C in an amount between about 0 and 0.1% by weight;   Mn in an amount between about 0 and 0.5% by weight;   Si in an amount between about 0 and 0.5% by weight; and   at least one reactive element in amount between about 0.01 and 0.1% by weight.   
     
     
         9 . The ignition device as defined in  claim 4  wherein said alloy more specifically comprises:
 Cr in an amount between about 20 and 22% by weight; Al in an amount between about 5 and 6% by weight; and Fe in an amount between about 72 and 75% by weight.   
     
     
         10 . The ignition device as defined in  claim 9  wherein said alloy further comprises:
 Ni in an amount between about 0 and 0.3% by weight;   Zr in an amount between about 0.01 and 0.1% by weight; Ti in an amount between about 0.01 and 0.1% by weight; Y in an amount between about 0.03 and 0.15% by weight; C in an amount between about 0.01 and 0.1% by weight; Mn in an amount between about 0 and 0.5% by weight; and Si in an amount between about 0 and 0.3% by weight.   
     
     
         11 . The ignition device as defined in  claim 8  wherein the reactive element is selected from a group consisting of Y, Zr, Nb, La, Hf and Ta. 
     
     
         12 . The ignition device as defined in  claim 4 , further comprising a firing tip attached to said electrode. 
     
     
         13 . The ignition device as defined in  claim 1 , further comprising, by weight: 0.005-0.5% zirconium and 0.001-0.10% boron. 
     
     
         14 . The ignition device as defined in  claim 4 , further comprising, by weight: 0.005-0.5% zirconium and 0.001-0.10% boron. 
     
     
         15 . The ignition device as defined in  claim 3 , wherein said sparking tip comprises one of gold, a gold alloy, a platinum group metal or a tungsten alloy. 
     
     
         16 . The ignition device as defined in  claim 15 , wherein said platinum group metal comprises at least one element selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium and rhenium. 
     
     
         17 . The ignition device as defined in  claim 16 , wherein said platinum group metal further comprises at least one element selected from the group consisting of nickel, chromium, iron, manganese, copper, aluminum, cobalt, tungsten, yttrium, zirconium, hafnium, lanthanum, cerium and neodymium. 
     
     
         18 . The ignition device as defined in  claim 12 , wherein said sparking tip comprises one of gold, a gold alloy, a platinum group metal or a tungsten alloy. 
     
     
         19 . The ignition device as defined in  claim 18 , wherein said platinum group metal comprises at least one element selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium and rhenium. 
     
     
         20 . The ignition device as defined in  claim 19 , wherein said platinum group metal further comprises at least one element selected from the group consisting of nickel, chromium, iron, manganese, copper, aluminum, cobalt, tungsten, yttrium, zirconium, hafnium, lanthanum, cerium and neodymium.