High temperature nitriding of titanium parts
AssigneeThe Boeing Company
InventorsDale J. Weires, Scott M. Holder, Julia H. Grogan
Life of this patent
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Abstract
A method and apparatus for manufacturing a part. The part may be positioned in a chamber. The part may be comprised of a metal and may be a positioned part. A gas containing nitrogen may be sent into the chamber. An electromagnetic field may be generated in the chamber with the gas. The electromagnetic field may heat a portion of the metal in the positioned part to a temperature from about 60 percent to about 99 percent of the melting point of the metal such that the portion of the metal has a desired hardness. The portion of the metal may extend from a surface of the positioned part to a selected depth from the surface.
Claims13
A method for manufacturing a part, the method comprising:
- positioning the part in a chamber in which the part is comprised of a metal;
- sending a gas containing nitrogen into the chamber using a gas delivery system;
- generating, using an induction coil system comprising a number of induction coils, a dual frequency electromagnetic field in the chamber with the gas in which the dual frequency electromagnetic field selectively heats a portion of the metal in the positioned part, in which the portion of the metal extends from a surface of the positioned part to a depth from the surface, to a temperature from about 60 percent to about 99 percent of a melting point of the metal;
- and
- cooling the part using a cooling ring manifold connected to the gas delivery system, the cooling ring manifold nested within the number of induction coils.
A method for forming a case on a titanium part, the method comprising:
- positioning the titanium part in a chamber in which the titanium part is comprised of a metal and is a positioned part, in which the metal is selected from the group consisting of titanium and a titanium alloy and in which the titanium part is selected from the group consisting of a gear, a bearing, a crankshaft, a camshaft, a cam follower, a valve, an extruder screw, a die, a bushing, a pin, and an injector;
- after removing all air from the chamber, sending a gas containing nitrogen into the vacuum chamber, using a gas delivery system, after applying the vacuum in the vacuum chamber to generate a pressure of up to about 150 pounds per square inch inside the vacuum chamber;
- generating a dual frequency electromagnetic field in the chamber with the gas, using an induction coil system comprising a number of induction coils, for up to about 30 minutes in which the dual frequency electromagnetic field has a first frequency and a second frequency, in which the dual frequency electromagnetic field selectively heats a first portion of the metal in the positioned part to a temperature from about 60 percent to about 99 percent of a melting point of the metal such that the first portion of the metal has a hardness while reducing changes to mechanical properties of the positioned part below a depth in a second portion of the metal in which the first portion of the metal extends from a surface of the positioned part to the depth from the surface, the depth is about 0.005 inches or greater, and the first portion is the case for the positioned part;
- and
- cooling the part using a cooling ring manifold connected to the gas delivery system, the cooling ring manifold nested within the number of induction coils.
Dependencies are inferred from the claim text.