Patent ID: 7879203

Claim:
A method of depositing a coating on a surface of a component, said method comprising: providing a cooling tube secured to a chamber so that a closed end of the cooling tube is disposed within the chamber and an oppositely-disposed end of the cooling tube is outside the chamber, a drive tube axially movable within the cooling tube, means for axially moving the drive tube within the cooling tube, and at least one magnet coaxially mounted on the drive tube adjacent a distal end thereof for axial movement with the drive tube within the cooling tube; providing a hollow cathode comprising at least a first coating material having an axial length and defining an outer circumferential surface of the cathode, the cathode having a center axis, an inner circumferential surface defining a hollow bore within the cathode, an open end defined by the bore at a first axial end of the cathode, and an oppositely-disposed second axial end; mounting the cathode on the closed end of the cooling tube by slip-fitting the open end of the cathode over the closed end of the cooling tube so that the cathode and the first coating material thereof surround the distal end of the drive tube and the magnet mounted thereon; connecting a power source to the cathode; subjecting the cathode, an anode, and the component to a vacuum environment within the chamber; applying a current to the cathode to form an arc at the outer circumferential surface of the cathode to remove portions of the first coating material from the outer circumferential surface and form a cloud of the first coating material within the vacuum environment, the arc moving circumferentially around the cathode in the axial vicinity of the magnet; operating the axial moving means to axially move the drive tube and the magnet mounted thereto within the bore of the cathode to cause the arc to move axially over the axial length of the first coating material as the arc continues to move circumferentially around the cathode in the axial vicinity of the magnet; and depositing the first coating material from the cloud onto a surface of the component.