Spark plug including electrodes with low swelling rate and high corrosion resistance

1. A spark plug ( 20 ) comprising:

a center electrode ( 24 ) and a ground electrode ( 22 ),

at least one of said electrodes ( 22 , 24 ) including a core ( 26 ) formed of a copper (Cu) alloy and a clad ( 28 ) formed of a nickel (Ni) alloy covering said core ( 26 ),

said Cu alloy including, in weight percent of said Cu alloy, Cu in an amount of at least 98.5 weight percent and at least one of Zr and Cr, and

said Ni alloy including, in weight percent of said Ni alloy, Ni in an amount of at least 90.0 weight percent and at least one of a Group 3 element, a Group 4 element, a Group 13 element, chromium (Cr), silicon (Si), and manganese (Mn).

2. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes, in weight percent of said Cu alloy, said at least one of Zr and Cr in a total amount of at least 0.05 weight percent.

3. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes a matrix of said Cu and precipitates of said at least one of Zr and Cu dispersed in said Cu matrix.

4. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes Cu in an amount up to 99.95 weight percent.

5. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes at least one of Zr and Cr in an amount up to 1.5 weight percent.

6. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes at least one of tellurium (Te), selenium (Se), iron (Fe), silver (Ag), boron (B), beryllium (Be), phosphorous (P), titanium (Ti), and sulfur (S) in a total amount up to 1.45 weight percent.

7. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes at least one of tellurium (Te), selenium (Se), iron (Fe), silver (Ag), boron (B), beryllium (Be), phosphorous (P), titanium (Ti), and sulfur (S) in a total amount of at least 0.01 weight percent.

8. The spark plug ( 20 ) of claim 6 wherein said Cu of said Cu alloy is a matrix and said at least one of tellurium (Te), selenium (Se), iron (Fe), silver (Ag), boron (B), beryllium (Be), phosphorous (P), titanium (Ti), and sulfur (S) are precipitates dispersed in said Cu matrix.

9. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes Cu in an amount of 98.81 weight percent to 99.05 weight percent and Zr in an amount of 0.05 weight percent to 0.15 weight percent.

10. The spark plug ( 20 ) of claim 1 wherein said Cu alloy includes Cu in an amount of 99.81 weight percent to 99.95 weight percent, Zr in an amount of 0.05 weight percent to 0.09 weight percent, and Cr in an amount of 0.9 weight percent to 1.10 weight percent.

11. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes Ni in an amount up to 97.9 weight percent.

12. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes at least one of a Group 3 element, a Group 4 element, a Group 13 element, chromium (Cr), silicon (Si), and manganese (Mn) in a total amount up to 10.0 weight percent.

13. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes at least one of a Group 3 element, a Group 4 element, a Group 13 element, chromium (Cr), silicon (Si), and manganese (Mn) in a total amount of at least 1.0 weight percent.

14. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes said at least one Group 3 element in an amount of 0.01 weight percent to 0.2 weight percent.

15. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes said at least one Group 4 element in an amount of 0.01 weight percent to 0.5 weight percent.

16. The spark plug ( 20 ) of claim 1 wherein said at least one Group 13 element includes Al.

17. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes at least one of Si, Cr, Mn, and Zr.

18. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes Ni in an amount of 96.8 weight percent to 97.9 weight percent, Al in an amount of 1.0 weight percent to 1.5 weight percent, Si in an amount of 1.0 weight percent to 1.5 weight percent, and Y in an amount of 0.01 weight percent to 0.2 weight percent.

19. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes Ni in an amount of 94.85 weight percent to 95.9 weight percent, Cr in an amount of 1.65 weight percent to 1.90 weight percent, Mn in an amount of 1.8 weight percent to 2.1 weight percent, Si in an amount of 0.35 weight percent to 0.55 weight percent, Ti in an amount of 0.2 weight percent to 0.4 weight percent, and Zr in an amount of 0.1 weight percent to 0.2 weight percent.

20. The spark plug ( 20 ) of claim 1 wherein said Ni alloy includes Ni in an amount of 91.30 weight percent to 99.69 weight percent; Al in an amount of 0.1 weight percent to 2.0 weight percent; Si in an amount of 0.1 weight percent to 2.0 weight percent; Cr in an amount of 0.1 weight percent to 2.0 weight percent; Mn in an amount of 0.1 weight percent to 2.0 weight percent; and at least one of Y in an amount of 0.01 weight percent to 0.1 weight percent, Zr in an amount of 0.01 weight percent to 0.2 weight percent and, Ti in an amount of 0.05 weight percent to 0.4 weight percent.

21. An electrode ( 22 , 24 ) for use in a spark plug ( 20 ) comprising:

a core ( 26 ) formed of a copper (Cu) alloy,

a clad ( 28 ) formed of a nickel (Ni) alloy covering said core ( 26 ),

said Cu alloy including, in weight percent of said Cu alloy, Cu in an amount of at least 98.5 weight percent and at least one of Zr and Cr, and

said Ni alloy including, in weight percent of said Ni alloy, Ni in an amount of at least 90.0 weight percent and at least one of a Group 3 element, a Group 4 element, a Group 13 element, chromium (Cr), silicon (Si), and manganese (Mn).