Me-N—C catalysts, wherein Me can include a transition metal, Mn, Fe, Co, or a combination of metals with Me-INU moieties located at the exterior surface of the Me-N—C catalysts are produced by a chemical vapor deposition synthesis. The synthesis methods can utilize non-solid-contact pyrolysis wherein a metal salt can be vaporized. Gaseous metal from the vaporized metal salt can displace a metal M from the N—C zeolitic imidazolate framework. The non-solid-contact pyrolysis does not mix solid iron precursors (e.g., Me=Mn, Fe, or Co) with the solid N—C zeolitic imidazolate framework precursors during or before the synthesis, which improves the process compared to conventional methods.

Disclosed is a method for surface-modifying titanium alloy, comprising the following steps: carburizing titanium alloy in solid carburizing agent A and solid carburizing agent B, and then performing gas co-infiltration to realize surface modification treatment of titanium alloy; the solid carburizing agent A includes raw materials of charcoal powder a, barium carbonate, calcium carbonate, barium acetate, urea and cerium carbonate, and the solid carburizing agent B includes raw materials of charcoal powder b, barium carbonate, calcium carbonate and cerium carbonate; and the gases used in the gas co-infiltration are ammonia, air and acetylene.

Disclosed is a method for surface-modifying titanium alloy, comprising the following steps: carburizing titanium alloy in solid carburizing agent A and solid carburizing agent B, and then performing gas co-infiltration to realize surface modification treatment of titanium alloy; the solid carburizing agent A includes raw materials of charcoal powder a, barium carbonate, calcium carbonate, barium acetate, urea and cerium carbonate, and the solid carburizing agent B includes raw materials of charcoal powder b, barium carbonate, calcium carbonate and cerium carbonate; and the gases used in the gas co-infiltration are ammonia, air and acetylene.

An embodiment of the invention describes a method of treating an article to improve its corrosion resistance. The method includes the step of nitriding the article in a cyanide-free nitriding bath to obtain a nitrided article, heating the nitrided article in an atmosphere having nitrogen and carbon-carburizing to obtain a nitrided oxidised article. Further, in certain embodiments, the oxidised nitrided article may be coated with a metallic layer. The oxidised nitrided article with the metallic coating has improved corrosion resistance.

There is provided a compact for a magnet which can produce a magnetic member having high coercive force. The compact for a magnet is produced by compression-molding a rare earth-iron-based alloy powder containing a plurality of particles of a rare earth-iron-based alloy containing a rare earth element and iron, wherein the rare earth-iron-based alloy satisfies configurations (a) to (c) below and has 5% by volume or more and 20% by volume or less of voids formed therein. (a) Having a structure containing 10% by mass or more and 30% by mass or less of Sm, 10% by mass or less of Mn, and the balance consisting of Fe and inevitable impurities. (b) A composition, Sm.sub.2MN.sub.xFe.sub.17-x (x=0.1 or more and 2.5 or less). (c) An average crystal grain diameter of 700 nm or less.

A pressure sensor includes a flexible diaphragm which is flexed by pressure changes and a coating layer on one surface of the diaphragm. The diaphragm is a single layer containing silicon, nitrogen, and oxygen. Further, the coating layer contains silicon oxynitride. Also, the coating layer has a nitrogen concentration distribution that varies across the thickness of the coating layer.

A method for producing a surface-hardened material, comprising: an immersion step of immersing an iron steel material having nitrogen attached in the form of a solid solution on the surface thereof in a melt containing a chloride at a temperature ranging from 650° C. to 900° C.; and a cooling step of cooling the immersed iron steel material to a temperature equal to or lower than a martensitic transformation start temperature at a cooling rate equal to or higher than a lower critical cooling rare at which martensitic transformation starts.

A surface treatment layer for a titanium-containing substrate includes a disordered metal oxide lattice having metal nitride compounds doped in the disordered metal oxide lattice. A method of surface treating a metal substrate includes introducing oxygen to a titanium-containing substrate to thereby form an oxide layer within the titanium-containing substrate, and, after the step of introducing oxygen, introducing nitrogen to the titanium-containing substrate to thereby modify the oxide layer to form a surface treatment layer.

An embodiment of the invention describes a method of treating an article to improve its corrosion resistance. The method includes the step of nitriding the article in a cyanide-free nitriding bath to obtain a nitrided article, heating the nitrided article in an atmosphere having nitrogen and carbon-carburizing to obtain a nitrided oxidised article. Further, in certain embodiments, the oxidised nitrided article may be coated with a metallic layer. The oxidised nitrided article with the metallic coating has improved corrosion resistance.

The present invention relates to a method of oxygen hardening a Group IV metal, the method comprising the steps of: providing a workpiece of a Group IV metal in its final shape; oxidising the Group IV metal over an oxidising duration of at least 10 minutes in an oxidising atmosphere at a first temperature to provide a non-stratified Group IV metal oxide on the surface of the workpiece using a gaseous oxidising species having an upper temperature limit of up to 800° C. wherein the first temperature is in the range of 500° C. and the upper temperature limit of the gaseous oxidising species; diffusing oxygen from the non-stratified Group IV metal oxide into the Group IV metal in an inert atmosphere at a second temperature in the range of 500° C. to 800° C. and at a partial pressure of the gaseous oxidising species of up to 10-4 mbar over a diffusive duration of at least 0.1 hour to provide a superficial diffusion zone comprising oxygen in solid solution. In another aspect, the invention relates to a Group IV metal component comprising a material core having a core hardness and a surface hardness of at least the core hardness +200 HV.sub.0.025. The component is obtainable in the method of the invention.