The invention relates to a method for producing a sintered component comprising the steps: providing a metallic powder; filling the powder into a powder press; pressing the powder to form a green compact; removing the green compact from the powder press; sintering the green compact into a sintered component with pores; optional redensification of the sintered component; hardening of the sintered component, wherein the pores of the sintered component, prior to hardening at least in that region of the surface of the sintered component which is subjected to a hardening, are at least partially filled with a filling agent.

A method for low-temperature interstitial case formation on a self-passivating metal workpiece includes exposing the workpiece in a heated gaseous environment comprising oxygen to pyrolysis products of a nonpolymeric reagent comprising nitrogen and carbon.

A method for vacuum heat treating Nb, such as is used in superconducting radio frequency cavities, to engineer the interstitial oxygen profile with depth into the surface to conveniently optimize the low-temperature rf surface resistance of the material. An example application is heating of 1.3 GHz accelerating structures between 250-400° C. to achieve a very high quality factor of 5×10.sup.10 at 2.0 K. With data supplied by secondary ion mass spectrometry measurements, application of oxide decomposition and oxygen diffusion theory was applied to quantify previously unknown parameters crucial in achieving the oxygen alloy concentration profiles required to optimize the rf surface resistance. RF measurements of vacuum heat treated Nb superconducting radio frequency cavities confirmed the minimized surface resistance (higher Q.sub.0) previously expected only from 800° C. diffusive alloying with nitrogen.

Metal components subject to wear or contact fatigue in a first area, and subject to bending, axial and/or torsional stress loading in a second area comprise a surface hardened, first surface layer in the first area, and a surface compressive-stress treated, second surface layer in the second area. The second surface layer has a material hardness different from, and typically lower than, the first surface layer, and induced residual compressive stress to improve fatigue strength. Example components described include a gear, a cog, a pinion, a rack, a splined shaft, a splined coupling, a torqueing tool and a nut driving tool. A hybrid manufacturing process is described, including area-selective surface hardening combined with a process to add compressive stress to fatigue failure prone areas.

The present invention is directed to methods for formation of refractory carbide, nitride, and boride coatings without use of a binding agent. The present invention is directed to methods of creating refractory coatings with controlled porosity. Refractory coatings can be formed from refractory metal, metal oxide, or metal/metal oxide composite refractory coating precursor of the 9 refractory metals encompassed by groups 4-6 and periods 4-6 of the periodic table; non-metallic elements (e.g. Si & B) and their oxides (i.e. SiO.sub.2 & B.sub.2O.sub.3) are also pertinent. The conversion of the refractory coating precursor to refractory carbide, nitride or boride is achieved via carburization, nitridization, or boridization in the presence of carbon-containing (e.g. CH.sub.4), nitrogen containing (e.g. NH.sub.3), and boron-containing (e.g. B.sub.2H.sub.6) gaseous species. Any known technique of applying the refractory coating precursor can be used. The porosity of resultant refractory coatings is controlled through compositional manipulation of composite refractory coating precursors.

The present invention is directed to methods for formation of refractory carbide, nitride, and boride coatings without use of a binding agent. The present invention is directed to methods of creating refractory coatings with controlled porosity. Refractory coatings can be formed from refractory metal, metal oxide, or metal/metal oxide composite refractory coating precursor of the 9 refractory metals encompassed by groups 4-6 and periods 4-6 of the periodic table; non-metallic elements (e.g. Si & B) and their oxides (i.e. SiO.sub.2 & B.sub.2O.sub.3) are also pertinent. The conversion of the refractory coating precursor to refractory carbide, nitride or boride is achieved via carburization, nitridization, or boridization in the presence of carbon-containing (e.g. CH.sub.4), nitrogen containing (e.g. NH.sub.3), and boron-containing (e.g. B.sub.2H.sub.6) gaseous species. Any known technique of applying the refractory coating precursor can be used. The porosity of resultant refractory coatings is controlled through compositional manipulation of composite refractory coating precursors.

A method for producing metal-based micro-porous structures includes continuously feeding a solid green part and a gas flow into a tunnel reactor having an aspect ratio greater than 2, wherein the solid green part has a characteristic diffusion mass transfer dimension less than 1 mm and a gas in the gas flow is substantially free of oxidants, and chemically reacting the gas in the gas flow and the green part under a predetermined temperature profile along a length of the tunnel reactor for a sufficient time to convert the green part into a solid product having pore sizes in a range of 0.3 nm to 5 μm.

A method for producing metal-based micro-porous structures includes continuously feeding a solid green part and a gas flow into a tunnel reactor having an aspect ratio greater than 2, wherein the solid green part has a characteristic diffusion mass transfer dimension less than 1 mm and a gas in the gas flow is substantially free of oxidants, and chemically reacting the gas in the gas flow and the green part under a predetermined temperature profile along a length of the tunnel reactor for a sufficient time to convert the green part into a solid product having pore sizes in a range of 0.3 nm to 5 μm.

Provided is a fastening member having a base material including an aluminum alloy and an anticorrosive film with which the base material is coated. This anticorrosive film contains aluminum hydroxide oxide (AlO(OH)), and in a profile obtained from X-ray diffractometry with a Cu-Kα radiation on the fastening member, a peak intensity ratio R (I.sub.B(020)/I.sub.Al(200)) is 0.003 or more and 0.1 or less, wherein I.sub.B(020) is an intensity of a diffraction peak of a (020) plane of aluminum hydroxide oxide, and I.sub.Al(200) is an intensity of a diffraction peak of a (200) plane of aluminum as a main peak. The anticorrosive film formed by the present invention is uniformly formed on the fastening member and excellent in stability and adhesion.

Provided is a fastening member having a base material including an aluminum alloy and an anticorrosive film with which the base material is coated. This anticorrosive film contains aluminum hydroxide oxide (AlO(OH)), and in a profile obtained from X-ray diffractometry with a Cu-Kα radiation on the fastening member, a peak intensity ratio R (I.sub.B(020)/I.sub.Al(200)) is 0.003 or more and 0.1 or less, wherein I.sub.B(020) is an intensity of a diffraction peak of a (020) plane of aluminum hydroxide oxide, and I.sub.Al(200) is an intensity of a diffraction peak of a (200) plane of aluminum as a main peak. The anticorrosive film formed by the present invention is uniformly formed on the fastening member and excellent in stability and adhesion.