Gas distribution ring assembly for plasma spray system

1. A gas distribution ring assembly for a plasma spray system, the ring assembly comprising:

a gas distribution ring including a plurality of openings allowing a gas to pass to an inner diameter thereof; and

a separate positioning ring axially aligned with the gas distribution ring between the gas distribution ring and an electrically charged outlet of the plasma spray system, wherein the positioning ring includes at least a pair of arcuate portions that mate to form the positioning ring.

2. The ring assembly of claim 1 , wherein the positioning ring includes an end face that is positioned in contact with an end face of the gas distribution ring.

3. The ring assembly of claim 1 , wherein the positioning ring and the gas distribution ring each include a ceramic.

4. The ring assembly of claim 1 , wherein the positioning ring includes a ceramic, and the gas distribution ring includes a metal.

5. The ring assembly of claim 4 , wherein the metal is selected from the group consisting of: a copper alloy, an iron alloy and a nickel alloy.

6. The ring assembly of claim 1 , wherein the positioning ring includes a pair of semi-circular mating portions.

7. The ring assembly of claim 1 , wherein each arcuate mating portion includes a seat at an end thereof that complementarily mates to a seat of an adjacent arcuate mating portion.

8. The ring assembly of claim 1 , wherein the positioning ring includes a discontinuity therein.

9. A plasma spray system comprising:

an outlet that includes a cathode and an anode;

an insulator member for electrically insulating the cathode from the anode;

a gas distribution ring assembly comprising:

a gas distribution ring for delivering a gas, the gas distribution ring including a plurality of openings allowing a gas to pass to an inner diameter thereof; and

a separate positioning ring axially aligned with the gas distribution ring between the gas distribution ring and the outlet, wherein the positioning ring includes at least a pair of arcuate, mating portions; and

a gas inlet for delivering the gas to the gas distribution ring.

10. The plasma spray system of claim 9 , wherein the positioning ring includes an end face that is positioned in contact with an end face of the gas distribution ring.

11. The plasma spray system of claim 9 , wherein the positioning ring and the gas distribution ring each include a ceramic.

12. The plasma spray system of claim 9 , wherein the positioning ring includes a ceramic, and the gas distribution ring includes a metal.

13. The plasma spray system of claim 12 , wherein the metal is selected from the group consisting of: a copper alloy, an iron alloy and a nickel alloy.

14. The plasma spray system of claim 9 , wherein the positioning ring includes a pair of semi-circular mating portions.

15. The plasma spray system of claim 9 , wherein each arcuate mating portion includes a seat at an end thereof that complementarily mates to a seat of an adjacent arcuate mating portion.

16. The plasma spray system of claim 9 , wherein the positioning ring includes a discontinuity therein.

17. A plasma spray system comprising:

a nozzle assembly including a cathode and an anode;

a voltage generator including a first electrical input to the cathode and a second electrical input to the anode;

an insulator member electrically insulating the cathode from the anode;

a gas distribution ring assembly comprising:

a gas distribution ring for delivering a gas to the nozzle assembly, the gas distribution ring including a plurality of openings allowing a gas to pass to an inner diameter thereof; and

a separate positioning ring axially aligned with the gas distribution ring between the gas distribution ring and the nozzle assembly, the positioning ring including an end face that is positioned in contact with an end face of the gas distribution ring, wherein the positioning ring includes at least a pair of arcuate, mating portions; and

a source of gas coupled to a gas inlet for delivery of the gas to the gas distribution ring.

18. The plasma spray system of claim 17 , wherein the positioning ring includes a discontinuity therein.