Method for removing a composite coating containing tantalum deposition and arc sprayed aluminum from ceramic substrates

1. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with the metallic layer in an acid solution comprising hydrochloric acid at a concentration of about 31% by volume of the solution for a time to substantially remove the metallic layer therefrom; and

annealing the ceramic substrate at a predetermined temperature sufficient to reduce pre-existing damage in the surface of the ceramic substrate by ramping the temperature using a heating ramp rate comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate said ramping the temperature of about 122° F./hour;

maintaining the first temperature for about an hour;

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour;

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour;

maintaining the third temperature for about 7 hours; and

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

2. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with the metallic layer in an acid solution comprising hydrochloric acid at a concentration of about 31% by volume of the solution for a time to substantially remove the metallic layer therefrom; and

annealing the ceramic substrate at a predetermined temperature sufficient to reduce pre-existing damage in the surface of the ceramic substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour; and

maintaining the first temperature for about an hour.

3. The method of claim 2 , wherein the ramping step further comprises:

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour.

4. The method of claim 3 , wherein the ramping step further comprises:

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; and

maintaining the third temperature for about 7 hours.

5. The method of claim 4 , wherein the ramping step further comprises:

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

6. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with a metallic layer comprising a composite layer formed from an aluminum coating in contact with the ceramic substrate and a tantalum deposition overlaying the aluminum coating in an acid solution of up to 31% hydrochloric acid by volume for a time to substantially remove the metallic layer therefrom; and

annealing the ceramic substrate at an elevated temperature sufficient to reduce pre-existing damage in the surface of the ceramic substrate through annealing by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of from about 302° F. at a first heating ramp rate of about 122° F./hour;

maintaining the first temperature for about an hour;

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour;

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour;

maintaining the third temperature for about 7 hours; and

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

7. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with a metallic layer comprising a composite layer formed from an aluminum coating in contact with the ceramic substrate and a tantalum deposition overlaying the aluminum coating in an acid solution of up to 31% hydrochloric acid by volume for a time to substantially remove the metallic layer therefrom; and

annealing the ceramic substrate at an elevated temperature sufficient to reduce pre-existing damage in the surface of the ceramic through annealing by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour; and

maintaining the first temperature for about an hour.

8. The method of claim 7 , wherein the ramping step further comprises:

heating to a second temperature of about 752″F at a second heating ramp of about 212° F./hour.

9. The method of claim 8 , wherein the ramping step further comprises:

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; and

maintaining the third temperature for about 7 hours.

10. The method of claim 9 , wherein the ramping step farther comprises:

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

11. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with the metallic layer formed from one metal in an acid solution of up to 31% hydrochloric acid by volume for a time to remove a portion of the metallic layer therefrom; and

annealing the ceramic substrate subsequent to the immersion step at an elevated temperature sufficient to reduce pre-existing damage in the surface of the substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour;

maintaining the first temperature for about an hour;

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour;

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour;

maintaining the third temperature for about 7 hours; and

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

12. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with the metallic layer formed from one metal in an acid solution of up to 31% hydrochloric acid by volume for a time to remove a portion of the metallic layer therefrom; and

annealing the ceramic substrate subsequent to the immersion step at an elevated temperature sufficient to reduce pre-existing damage in the surface of the substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour; and

maintaining the first temperature for about an hour.

13. The method of claim 12 , wherein the ramping step further comprises:

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour.

14. The method of claim 13 , wherein the ramping step further comprises:

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; and

maintaining the third temperature for about 7 hours.

15. The method of claim 14 , wherein the ramping step further comprises:

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

16. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with the metallic layer formed from one metal in an acid solution comprising hydrochloric acid at a concentration of up to 31% by volume of the solution for a time to remove a portion of the metallic layer therefrom; and

annealing the ceramic substrate subsequent to the immersion step at an elevated temperature sufficient to reduce pre-existing damage in the surface of the substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of from about 302° F. at a first heating ramp rate of about 122° F./hour;

maintaining the first temperature for about an hour;

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour;

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour;

maintaining the third temperature for about 7 hours; and

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

17. A method for removing a metallic layer from a surface of a ceramic substrate comprising the steps of:

immersing the ceramic substrate coated with the metallic layer formed from one metal in an acid solution comprising hydrochloric acid at a concentration of up to 31% by volume of the solution for a time to remove a portion of the metallic layer therefrom; and

annealing the ceramic substrate subsequent to the immersion step at an elevated temperature sufficient to reduce pre-existing damage in the surface of the substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour; and

maintaining the first temperature for about an hour.

18. The method of claim 17 , wherein the ramping step further comprises:

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour.

19. The method of claim 18 , wherein the ramping step further comprises:

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; and

maintaining the third temperature for about 7 hours.

20. The method of claim 19 , wherein the ramping step further comprises:

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

21. A method for refurbishing a deposition ring comprising a ceramic substrate coated with a metallic composite layer having an aluminum layer in contact with a surface of the ceramic substrate and a tantalum layer deposited over the aluminum layer comprising the steps of:

immersing the ceramic substrate coated with the metallic composite layer in a solution of up to 31% hydrochloric acid by volume for a time to remove a portion of the metallic layer therefrom;

removing the ceramic substrate from the acid solution;

rinsing the ceramic substrate in a rinse solution;

drying the substrate;

annealing the ceramic substrate at a predetermined temperature for a time to reduce damage or defects in the surface of the ceramic substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour;

maintaining the first temperature for about an hour;

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour;

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour;

maintaining the third temperature for about 7 hours; and

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour; and

coating the ceramic substrate with a new metallic layer.

22. A method for refurbishing a deposition ring comprising a ceramic substrate coated with a metallic composite layer having an aluminum layer in contact with a surface of the ceramic substrate and a tantalum layer deposited over the aluminum layer comprising the steps of:

immersing the ceramic substrate coated with the metallic composite layer in a solution of up to 31% hydrochloric acid by volume for a time to remove a portion of the metallic layer therefrom;

removing the ceramic substrate from the acid solution;

rinsing the ceramic substrate in a rinse solution;

drying the substrate;

annealing the ceramic substrate at a predetermined temperature for a time to reduce damage or defects in the surface of the ceramic substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour; and

maintaining the first temperature for about an hour; and

coating the ceramic substrate with a new metallic layer.

23. The method of claim 22 , wherein the ramping step further comprises:

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour.

24. The method of claim 23 , wherein the ramping step further comprises:

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; and

maintaining the third temperature for about 7 hours.

25. The method of claim 24 , wherein the ramping step further comprises:

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.

26. A method for refurbishing a deposition ring comprising a ceramic substrate coated with a metallic composite layer having an aluminum layer in contact with a surface of the ceramic substrate and a tantalum layer deposited over the aluminum layer comprising the steps of:

immersing the ceramic substrate coated with the metallic composite layer in an acid solution including about 31% hydrochloric acid by volume for a sufficient time to substantially remove the metallic layer therefrom;

removing the ceramic substrate from the acid solution;

rinsing the ceramic substrate in a rinse solution;

drying the substrate;

annealing the ceramic substrate at a predetermined temperature for a time to reduce damage or defects in the surface of the ceramic substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of from about 302° F. at a first heating ramp rate of about 122° F./hour;

maintaining the first temperature for about an hour;

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour;

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour;

maintaining the third temperature for about 7 hours; and

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour; and

coating the ceramic substrate with a new metallic layer.

27. A method for refurbishing a deposition ring comprising a ceramic substrate coated with a metallic composite layer having an aluminum layer in contact with a surface of the ceramic substrate and a tantalum layer deposited over the aluminum layer comprising the steps of:

immersing the ceramic substrate coated with the metallic composite layer in an acid solution including about 31% hydrochloric acid by volume for a sufficient time to substantially remove the metallic layer therefrom;

removing the ceramic substrate from the acid solution;

rinsing the ceramic substrate in a rinse solution;

drying the substrate;

annealing the ceramic substrate at a predetermined temperature for a sufficient time to reduce damage or defects in the surface of the ceramic substrate by ramping the temperature at a heating ramp rate said ramping the temperature comprising:

heating to a first temperature of about 302° F. at a first heating ramp rate of about 122° F./hour; and

maintaining the first temperature for about an hour; and

coating the ceramic substrate with a new metallic layer.

28. The method of claim 27 , wherein the ramping step further comprises:

heating to a second temperature of about 752° F. at a second heating ramp rate of about 212° F./hour.

29. The method of claim 28 , wherein the ramping step further comprises:

heating to a third temperature of about 1652° F. at a third heating ramp rate of about 347° F./hour; and

maintaining the third temperature for about 7 hours.

30. The method of claim 29 , wherein the ramping step further comprises:

allowing to cool to a fourth temperature of about 100° F. at a cooling ramp rate of about minus 210° F./hour.