Cathodic arc deposition apparatus and method

Patent metadata

Field	Value
Publication number	US-2017372871-A1
Application number	US-201715699429-A
Country	US
Kind code	A1
Filing date	Sep 8, 2017
Priority date	Oct 8, 2013
Publication date	Dec 28, 2017
Grant date	—

Abstract

A coating method includes vaporizing a portion of a cathode to form a metallic plasma, and directing the metallic plasma toward the workpiece. A first magnetic field generator, disposed in a first electrically conductive portion of a first stinger cup, is operated to steer the electrical arc about at least one evaporative surface of the cathode. a second portion of the electrically conductive stinger cup is selectively contacted with the cathode, and the first portion of the first stinger cup is spaced from the second portion from by a thermally insulating layer therebetween. The thermally insulating layer is disposed directly between the first magnetic field generator and the cathode when the first stinger cup is in contact with the cathode.

First claim

1 . 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 at least one evaporative surface of the cathode; biasing the cathode with a positive potential; vaporizing a portion of the cathode evaporative surface by initiating 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 of the workpiece to be coated with a negative potential equal to or less than a negative potential of the anode; and operating a first magnetic field generator disposed in a first electrically conductive portion of a first stinger cup, thereby steering the electrical arc about the at least one evaporative surface of the cathode; selectively contacting a second portion of the electrically conductive stinger cup with the cathode, the first portion of the first stinger cup spaced from the second portion from by a thermally insulating layer therebetween, such that the thermally insulating layer is disposed directly between the first magnetic field generator and the cathode when the first stinger cup is in contact with the cathode.

2 . The method of claim 1 , 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.

3 . The method of claim 2 , wherein the plurality of workpieces include at least one airfoil.

4 . The method of claim 1 , wherein at least one of the first portion and the second portion of the stinger cup comprises copper.

5 . The method of claim 1 , wherein the thermally insulating layer is non-metallic.

6 . The method of claim 5 , wherein the thermally insulating layer comprises air.

7 . The method of claim 6 , further comprising:
maintaining the thermally insulating layer under partial vacuum.

8 . The method of claim 1 , further comprising:
operating a second magnetic field generator disposed within a second stinger cup.

9 . The method of claim 8 , wherein the second stinger cup forms at least a portion of a cathode support base.

10 . The method of claim 8 , wherein the second stinger cup comprises a first electrically conductive portion spaced from a second electrically conductive portion by a thermally insulating layer such that the thermally insulating layer of the second stinger cup is disposed directly between the second magnetic field generator and the cathode.

11 . The method of claim 1 , wherein the cathode comprises a puck including the evaporative surface formed from a first metallic material.

12 . The method of claim 11 , wherein the first metallic material comprises a metal selected from the group consisting of: nickel, cobalt, chromium, aluminum, titanium, yttrium, zirconium, and alloys thereof.

13 . The method of claim 1 , further comprising:
maintaining an inert atmosphere in the vessel; and solidifying the metallic plasma on the workpiece to form a metallic coating thereon.

14 . The method of claim 1 , 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.

15 . The method of claim 14 , wherein the at least one gas is selected from the group consisting of: oxygen, nitrogen, carbon dioxide, and combinations thereof.

16 . The method of claim 14 , wherein the ceramic coating is selected from the group consisting of: oxides, nitrides, carbides, carbo-nitrides, oxycarbo-nitrides, and combinations thereof.

17 . The method of claim 14 , 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

• C23C14/081

  of aluminium, magnesium or beryllium · CPC title

• H01J37/3435

  Target holders (includes backing plates and endblocks) · CPC title

• C23C14/0641

  Nitrides (C23C14/0617 takes precedence) · CPC title

• H01J37/32816

  Pressure · CPC title

• H01J37/32669

  Particular magnets or magnet arrangements for controlling the discharge · CPC title