A permanent magnet may include a Fe.sub.16N.sub.2 phase in a strained state. In some examples, strain may be preserved within the permanent magnet by a technique that includes etching an iron nitride-containing workpiece including Fe.sub.16N.sub.2 to introduce texture, straining the workpiece, and annealing the workpiece. In some examples, strain may be preserved within the permanent magnet by a technique that includes applying at a first temperature a layer of material to an iron nitride-containing workpiece including Fe.sub.16N.sub.2, and bringing the layer of material and the iron nitride-containing workpiece to a second temperature, where the material has a different coefficient of thermal expansion than the iron nitride-containing workpiece. A permanent magnet including an Fe.sub.16N.sub.2 phase with preserved strain also is disclosed.

A permanent magnet may include a Fe.sub.16N.sub.2 phase in a strained state. In some examples, strain may be preserved within the permanent magnet by a technique that includes etching an iron nitride-containing workpiece including Fe.sub.16N.sub.2 to introduce texture, straining the workpiece, and annealing the workpiece. In some examples, strain may be preserved within the permanent magnet by a technique that includes applying at a first temperature a layer of material to an iron nitride-containing workpiece including Fe.sub.16N.sub.2, and bringing the layer of material and the iron nitride-containing workpiece to a second temperature, where the material has a different coefficient of thermal expansion than the iron nitride-containing workpiece. A permanent magnet including an Fe.sub.16N.sub.2 phase with preserved strain also is disclosed.

A method of applying a metal comprising titanium to a substrate is disclosed. The method comprises nitriding the surface of metal powder particles comprising titanium by contacting the particles with a first gas comprising nitrogen in a fluidized bed reactor, and depositing the metal powder particles onto the substrate with cold spray deposition using a second gas.

A method of applying a metal comprising titanium to a substrate is disclosed. The method comprises nitriding the surface of metal powder particles comprising titanium by contacting the particles with a first gas comprising nitrogen in a fluidized bed reactor, and depositing the metal powder particles onto the substrate with cold spray deposition using a second gas.

A surface treatment for a metal substrate includes a nitride layer and a diamond-like carbon coating on said nitride layer. The metal substrate can be a titanium-containing substrate. The nitride layer and diamond-like carbon coating serve to improve the tribological properties of the metal substrate.

A surface treatment for a metal substrate includes a nitride layer and a diamond-like carbon coating on said nitride layer. The metal substrate can be a titanium-containing substrate. The nitride layer and diamond-like carbon coating serve to improve the tribological properties of the metal substrate.

Methods of hardening a case-nitrided metal article, methods of producing a hardened case-nitrided metal article, and hardened case-nitrided metal articles. The methods of hardening a case-nitrided metal article include heating the case-nitrided metal article to an aging temperature, maintaining the case-nitrided metal article at the aging temperature for an aging time, and cooling the case-nitrided metal article from the aging temperature. The methods of producing a hardened case-nitrided metal article include case-nitriding a metal article to produce a case-nitrided metal article and subsequently hardening the case-nitrided metal article. The hardened case-nitrided metal article comprises a body formed of a metal or a metal alloy, a surface surrounding the body, and a nitrided case layer formed in the body and extending inwardly from the surface of the body toward the core that includes a hardness that is greater than that of an otherwise equivalent case-nitrided metal article.

Methods of hardening a case-nitrided metal article, methods of producing a hardened case-nitrided metal article, and hardened case-nitrided metal articles. The methods of hardening a case-nitrided metal article include heating the case-nitrided metal article to an aging temperature, maintaining the case-nitrided metal article at the aging temperature for an aging time, and cooling the case-nitrided metal article from the aging temperature. The methods of producing a hardened case-nitrided metal article include case-nitriding a metal article to produce a case-nitrided metal article and subsequently hardening the case-nitrided metal article. The hardened case-nitrided metal article comprises a body formed of a metal or a metal alloy, a surface surrounding the body, and a nitrided case layer formed in the body and extending inwardly from the surface of the body toward the core that includes a hardness that is greater than that of an otherwise equivalent case-nitrided metal article.

Provided is a steel component with excellent surface fatigue strength. The steel component has a nitride compound layer with a thickness of 5.0 μm to 30.0 μm and a hardened layer in an order from a component surface to a component inside, where a thickness of a porous layer on an outermost surface of the nitride compound layer is 3.0 μm or less and 40.0% or less of a thickness of the nitride compound layer, and the hardened layer has a hardness of HV600 or more at a position of 50 μm inward from the component surface, a hardness of HV400 or more at a position from the component surface to the component inside of 400 μm, and a hardness of HV250 or more at a position from the component surface to the component inside of 600 μm.

Provided is a steel component with excellent surface fatigue strength. The steel component has a nitride compound layer with a thickness of 5.0 μm to 30.0 μm and a hardened layer in an order from a component surface to a component inside, where a thickness of a porous layer on an outermost surface of the nitride compound layer is 3.0 μm or less and 40.0% or less of a thickness of the nitride compound layer, and the hardened layer has a hardness of HV600 or more at a position of 50 μm inward from the component surface, a hardness of HV400 or more at a position from the component surface to the component inside of 400 μm, and a hardness of HV250 or more at a position from the component surface to the component inside of 600 μm.