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.

A braking band having an annular band body arranged around a rotation axis and made of one of gray cast iron, steel, aluminum or alloys thereof, has at least one braking surface having an activated band body portion for increasing adhesive capacity of at least one protective surface coating placed on the surface of the activated band body portion and having at least one material with elevated resistance to abrasion. The activated band body portion is arranged on the surface of the annular band body to form an outermost layer of the braking band with the at least one protective surface coating and has a rough profile having at least one channel delimited by at least one pair of projections, extending along a path at least partially surrounding the rotation axis and having a channel bottom and a first channel side forming an acute angle with the channel bottom and an opposite second channel side forming an obtuse angle with the channel bottom.

An article formed of a metal alloy is covered at least partially with a metal hydride and a shell metal to form an assembly. Load is applied to the assembly and the assembly is heated. The shell metal deforms around the article and the metal hydride and forms a gas proof seal. The metal hydride thermally decomposes to form hydrogen gas. At least a portion of the hydrogen gas dissociates and moves as monoatomic hydrogen into the article. The metal alloy can be a zirconium metal alloy, the metal hydride can be a zirconium metal hydride, and the shell metal can be substantially copper.

An article formed of a metal alloy is covered at least partially with a metal hydride and a shell metal to form an assembly. Load is applied to the assembly and the assembly is heated. The shell metal deforms around the article and the metal hydride and forms a gas proof seal. The metal hydride thermally decomposes to form hydrogen gas. At least a portion of the hydrogen gas dissociates and moves as monoatomic hydrogen into the article. The metal alloy can be a zirconium metal alloy, the metal hydride can be a zirconium metal hydride, and the shell metal can be substantially copper.

A carburized steel component, comprising a steel base including, by weight percent, from 0.08% to 0.35% carbon, 0.5% to 1.3% manganese, 0% to 0.35% silicon, 0.2% to 2.0% chromium, 0% to 4% nickel, 0% to 0.50% molybdenum, 0% to 0.06% niobium, and a remaining weight percent of iron, and a carburized layer of above 0.35% by weight carbon from a surface of the carburized layer to a carburized layer depth, wherein the carburized layer depth is from 0.5 mm to 3.0 mm, wherein the carburized layer comprises a microstructure including martensite, retained austenite, carbide, and less than 2% by volume non-martensitic transformation products (NMTP), and wherein the carburized layer includes a prior austenite average grain size of 3.0-8.0 microns from the surface to a depth of at least 0.2 mm.

A grain-oriented electrical steel sheet according to the present invention includes a base steel sheet having plural grooves on a surface and a glass film formed on the surface of the base steel sheet. In case of viewing region including grooves in cross section orthogonal to groove longitudinal direction, a straight line passing through peak point present on profile line of glass film and parallel to groove width direction orthogonal to sheet thickness direction in cross section is defined as reference line, a point present on boundary line between glass film and base steel sheet and present at lowest location in sheet thickness direction is defined as deepest point, and a point present on boundary line and present at the highest location in the sheet thickness direction in region having the deepest point in a center and having length of 2 μm in groove width direction is defined as shallowest point, a relationship between shortest distance A between reference line and deepest point and shortest distance B between reference line and shallowest point satisfies Expression (1).
0.1 μm≤A−B≤5.0 μm  (1)

Embodiments of the present disclosure generally relate to protective coatings on aerospace components and methods for depositing the protective coatings. In one or more embodiments, a method for producing a protective coating on an aerospace component includes depositing a metal oxide template layer on the aerospace component containing nickel and aluminum (e.g., nickel-aluminum superalloy) and heating the aerospace component containing the metal oxide template layer during a thermal process and/or an oxidation process. The thermal process and/or oxidation process includes diffusing aluminum contained within the aerospace component towards a surface of the aerospace component containing the metal oxide template layer, oxidizing the diffused aluminum to produce an aluminum oxide layer disposed between the aerospace component and the metal oxide template layer, and removing at least a portion of the metal oxide template layer while leaving the aluminum oxide layer.

An iron-based sintered alloy material having, at the surface of the material, a hardened layer exhibiting a martensite phase containing a solid solution of nitrogen in a supersaturated state. The iron-based sintered alloy material may contain at least one of chromium, copper, molybdenum, manganese and nickel. A production method for the iron-based sintered alloy material includes: subjecting an iron-based sintered alloy substrate containing carbon to a nitriding treatment by heating the substrate to a nitriding temperature of at least 590° C. in an atmosphere containing ammonia, and then performing quenching by rapidly cooling the substrate.

The present invention concerns a method for obtaining a finished or semi-finished zirconia-based article, the surface of the article having a metallic external appearance and non-zero surface electrical conductivity, wherein the method includes the steps of: taking at least one zirconia article, pre-shaped in its finished or semi-finished form; placing said article in a chamber in which a hydrogen and carbon/nitrogen gas mixture is heated; heating said article and the gas mixture using at least one resistive element traversed by an electric current to obtain dissociation of the hydrogen and carbon/nitrogen based gas molecules and an increase in the temperature of said article; keeping said article in the reactive atmosphere thus created to obtain diffusion of the carbon/nitrogen atoms in the external surface of said article.

The present invention concerns a method for obtaining a finished or semi-finished zirconia-based article, the surface of the article having a metallic external appearance and non-zero surface electrical conductivity, wherein the method includes the steps of: taking at least one zirconia article, pre-shaped in its finished or semi-finished form; placing said article in a chamber in which a hydrogen and carbon/nitrogen gas mixture is heated; heating said article and the gas mixture using at least one resistive element traversed by an electric current to obtain dissociation of the hydrogen and carbon/nitrogen based gas molecules and an increase in the temperature of said article; keeping said article in the reactive atmosphere thus created to obtain diffusion of the carbon/nitrogen atoms in the external surface of said article.