Cathodic arc deposition apparatus and method

Patent metadata

Field	Value
Publication number	US-2016260583-A1
Application number	US-201415027643-A
Country	US
Kind code	A1
Filing date	Sep 25, 2014
Priority date	Oct 8, 2013
Publication date	Sep 8, 2016
Grant date	—

Abstract

A cathodic arc coating apparatus includes a vessel, a cathode disposed in the vessel, and a stinger assembly. The stinger assembly includes a first magnetic field generator disposed in a first stinger cup in selective contact with the cathode. The first stinger cup has at least a first electrically conductive cup portion spaced from a second electrically conductive cup portion by a thermally insulating layer therebetween.

First claim

1 . A cathodic arc coating apparatus comprising:
a vessel; a cathode disposed in the vessel, the cathode having at least one evaporative surface; and a stinger assembly including at least a first magnetic field generator disposed in a first stinger cup in selective contact with the cathode, the first stinger cup having at least a first electrically conductive cup portion spaced from a second electrically conductive cup portion by a thermally insulating layer therebetween.

2 . The apparatus of claim 1 , wherein at least one of the first electrically conductive cup portion and the second electrically conductive cup portion is in selective contact with a first end surface of the cathode.

3 . The apparatus of claim 1 , wherein the cathode includes a puck comprising an evaporative surface formed of a metallic material.

4 . The apparatus of claim 3 , wherein the metallic material comprises a metal selected from the group consisting of: nickel, cobalt, chromium, aluminum, titanium, yttrium, zirconium, and alloys thereof.

5 . The apparatus of claim 1 , wherein the vessel contains an inert atmosphere.

6 . The apparatus of claim 1 , wherein the vessel contains a gas under partial pressure, the gas selected from the group consisting of: oxygen, nitrogen, carbon dioxide, and combinations thereof.

7 . The apparatus of claim 1 , further comprising:
a platter including a plurality of workpiece holders disposed about an axis of the cathode.

8 . The apparatus of claim 7 , wherein the plurality of workpiece holders are adapted to retain at least one airfoil.

9 . The apparatus of claim 1 , wherein at least one of the first cup portion and the second cup portion comprises copper.

10 . The apparatus of claim 1 , wherein the thermally insulating layer is non-metallic.

11 . The apparatus of claim 10 , wherein the thermally insulating layer comprises air.

12 . The apparatus of claim 10 , wherein the thermally insulating layer is maintained under partial vacuum.

13 . The apparatus of claim 1 , further comprising a cathode support base secured to, and electrically insulated from the vessel.

14 . The apparatus of claim 13 , further comprising: a second magnetic field generator disposed within the cathode support base.

15 . The apparatus of claim 14 , wherein the cathode support base comprises a second multi-part stinger cup, the second multi-part stinger cup having at least a first electrically conductive cup portion spaced from a second electrically conductive cup portion by a thermally insulating layer therebetween.

16 . A method for coating a workpiece, the method comprising:
positioning the workpiece in a cathodic arc deposition vessel such that a surface of the workpiece to be coated faces an evaporative surface of the cathode; vaporizing a portion of the cathode evaporative surface by generating an electrical arc between the cathode and an anode disposed in the vessel, the vaporized portion of the cathode forming a metallic plasma; directing the metallic plasma toward the workpiece by biasing the surface to be coated with a negative potential equal to or less than a negative potential of the anode; and steering the electrical arc about the cathode by operating a first magnetic field generator, the magnetic field generator disposed in a first multi-part stinger cup in selective contact with the cathode, the first stinger cup having at least a first electrically conductive cup portion spaced from a second electrically conductive cup portion by a thermally insulating layer therebetween.

17 . The method of claim 16 , further comprising:
positioning a plurality of workpieces in the vessel such that a surface of each workpiece to be coated faces the evaporative surface of the cathode.

18 . The method of claim 17 , wherein the plurality of workpieces include at least one airfoil.

19 . The method of claim 16 , wherein at least one of the first cup portion and the second cup portion comprises copper.

20 . The method of claim 16 , wherein the thermally insulating layer is non-metallic.

21 . The method of claim 20 , wherein the thermally insulating layer comprises air.

22 . The method of claim 20 , further comprising:
maintaining the thermally insulating layer under partial vacuum.

23 . The method of claim 16 , wherein the steering step further comprises:
operating a second magnetic field generator disposed within a second stinger cup.

24 . The method of claim 23 , wherein the second stinger cup forms at least a portion of a cathode support base.

25 . The method of claim 23 , wherein the second stinger cup comprises a multi-part cup with a first electrically conductive cup portion spaced from a second electrically conductive cup portion by a thermally insulating layer.

26 . The method of claim 16 , wherein the cathode comprises a puck including the evaporative surface formed from a first metallic material.

27 . The method of claim 26 , wherein the first metallic material comprises a metal selected from the group consisting of: nickel, cobalt, chromium, aluminum, titanium, yttrium, zirconium, and alloys thereof.

28 . The method of claim 16 , further comprising:
maintaining an inert atmosphere in the vessel; and solidifying the metallic plasma to form a metallic coating on the workpiece.

29 . The method of claim 16 , further comprising:
introducing at least one gas into the vessel such that the electrical arc vaporizes a portion of the at least one gas to form a nonmetallic plasma; directing the nonmetallic plasma to the biased surface of the workpiece; and solidifying the nonmetallic plasma along with the metallic plasma to form a ceramic coating on the workpiece.

30 . The method of claim 29 , wherein the at least one gas is selected from the group consisting of: oxygen, nitrogen, carbon dioxide, and combinations thereof.

31 . The method of claim 29 , wherein the ceramic coating is selected from the group consisting of: oxides, nitrides, carbides, carbo-nitrides, oxycarbo-nitrides, and combinations thereof.

32 . The method of claim 29 , wherein the ceramic coating is selected from the group consisting of: aluminum oxide, yttrium oxide, zirconium oxide, titanium nitride, and combinations thereof.

Assignees

• United Technologies Corp

Inventors

• Balzano Thomas
• Beers Russell A

Classifications

• H01J37/32816

  Pressure · CPC title

• H01J2237/332

  Coating · CPC title

• C23C14/083

  of refractory metals or yttrium · CPC title

• H01J37/32055

  Arc discharge · CPC title

• H01J37/32522

  Temperature · CPC title