Embodiments of the present invention provide a technique for forming a film having a high added value appearance quality and excellent hardness on the surface of a steel sheet in a short time.

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.

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.

A nanostructure is made of a plurality of nanocrystals on at least one surface or surface region of a titanium body. A method for generating such nanostructure is by means of hydrothermal oxidation. Thereby, the nanocrystals have a basic tetragonal-pyramidal shape, at least in some regions. The area density of the nanocrystals is between 40 and 400 per μm.sup.2, wherein the area density decreases with increasing crystal height. The average spacing of 50 to 160 nm of adjacent nanocrystals is obtained at a nanocrystal height of 23 to 100 nm. This provides a titanium-based, bactericidal and hydrophilic nanostructure for implant surfaces and, at the same time, a corresponding manufacturing method with which the size and distribution of the nanocrystals forming a nanostructure that facilitates healing can be determined.

A nanostructure is made of a plurality of nanocrystals on at least one surface or surface region of a titanium body. A method for generating such nanostructure is by means of hydrothermal oxidation. Thereby, the nanocrystals have a basic tetragonal-pyramidal shape, at least in some regions. The area density of the nanocrystals is between 40 and 400 per μm.sup.2, wherein the area density decreases with increasing crystal height. The average spacing of 50 to 160 nm of adjacent nanocrystals is obtained at a nanocrystal height of 23 to 100 nm. This provides a titanium-based, bactericidal and hydrophilic nanostructure for implant surfaces and, at the same time, a corresponding manufacturing method with which the size and distribution of the nanocrystals forming a nanostructure that facilitates healing can be determined.

A method of manufacturing a passivation film, which includes a passivation process in which a substrate on the surface of which at least one of germanium and molybdenum is contained is treated with a passivation gas containing an oxygen-containing compound, which is a compound containing an oxygen atom in the molecule, and hydrogen sulfide to form a passivation film containing a sulfur atom on the surface of the substrate. The concentration of the oxygen-containing compound in the passivation gas is from 0.001 mole ppm to less than 75 mole ppm.

Described is a method of manufacturing a gate-all-around electronic device. The method includes forming a thermal oxide layer though an enhanced in situ steam generation process in combination with atomic layer deposition of a low-κ layer. The thin thermal oxide layer passivates the interface between the silicon layer and the dielectric layer of the GAA. A passivation process after the deposition of the low-κ layer reduces the bulk trap and enhances the breakdown performance of the GAA transistor.

Described is a method of manufacturing a gate-all-around electronic device. The method includes forming a thermal oxide layer though an enhanced in situ steam generation process in combination with atomic layer deposition of a low-κ layer. The thin thermal oxide layer passivates the interface between the silicon layer and the dielectric layer of the GAA. A passivation process after the deposition of the low-κ layer reduces the bulk trap and enhances the breakdown performance of the GAA transistor.

A system for coating an interior surface of a heat exchanger includes a tank for storing the coating solution, a pump, a source line for supplying the coating solution to the heat exchanger, and a return line for returning the remainder of the coating solution to the tank. The system can include a pre-treatment line for supplying a pre-treatment solution to the heat exchanger and a water line for supplying water to the heat exchanger. An air compressor can be coupled to the heat exchanger to force the coating solution, the pre-treatment solution, or the water from the heat exchanger.

The invention relates to a method for patinating zinc surfaces of a structural element, including the steps of: providing a structural element with a zinc surface in a housing; providing an atmosphere around the zinc surface, wherein said atmosphere comprises carbon based gas and humidity; and heating the zinc surface for at least one hour, to provide a patinated zinc surface. The heating of the zinc surface occurs by heating the atmosphere to a temperature of at least 50° C., the humidity is at least 70%, and the carbon-based gas concentration is at least 5% by volume. The invention also relates to a patinated evaporative condenser in a closed-circuit cooling tower The patinated evaporative condenser in a closed-circuit cooling tower is by the method according to the invention. A system for patinating zinc surfaces according to the invention is also disclosed.