A process of converting an outer layer of an object made of a refractory metal, such as titanium, into a carbide of the refractory metal. A molten metal, such as molten lithium, is placed adjacent the outer surface of the object. The lithium does not react with the titanium, nor is it soluble within the titanium to any significant extent at the temperatures involved. The molten lithium contains elemental carbon, that is, free carbon atoms. At high temperature, the carbon diffuses into the titanium, and reacts with titanium atoms to form titanium carbide in an outer layer. Significantly, no other atoms are present, such as hydrogen or oxygen, which can cause problems, because they are blocked by the molten lithium.

A process of converting an outer layer of an object made of a refractory metal, such as titanium, into a carbide of the refractory metal. A molten metal, such as molten lithium, is placed adjacent the outer surface of the object. The lithium does not react with the titanium, nor is it soluble within the titanium to any significant extent at the temperatures involved. The molten lithium contains elemental carbon, that is, free carbon atoms. At high temperature, the carbon diffuses into the titanium, and reacts with titanium atoms to form titanium carbide in an outer layer. Significantly, no other atoms are present, such as hydrogen or oxygen, which can cause problems, because they are blocked by the molten lithium.

The invention relates to a method of providing a metallic surface with a protective diffusion layer, wherein a chromium-containing slip is applied to the surface and is then subjected to a heat treatment in order to produce the protective diffusion layer. In addition to the chromium powder, the slip contains silicon powder in order to shorten the hold time required in the heat treatment.

The present invention relates to a process for producing a diffusion layer for protecting temperature-stressed components, in particular of turbomachines, against oxidation and corrosion. The process comprises application of at least one slip to a component surface on which the diffusion layer is to be produced, and drying and/or hardening of the at least one slip by a heat treatment at a first temperature and diffusion heat treatment at a second temperature. The slip comprises Al-containing powder, Si-containing powder and a binder and also a Cr-containing powder which does not comprise any hexavalent chromium. In addition, the invention provides a corresponding slip.

The present invention relates to a process for producing a diffusion layer for protecting temperature-stressed components, in particular of turbomachines, against oxidation and corrosion. The process comprises application of at least one slip to a component surface on which the diffusion layer is to be produced, and drying and/or hardening of the at least one slip by a heat treatment at a first temperature and diffusion heat treatment at a second temperature. The slip comprises Al-containing powder, Si-containing powder and a binder and also a Cr-containing powder which does not comprise any hexavalent chromium. In addition, the invention provides a corresponding slip.

The present disclosure provides systems and methods for depositing a metal layer adjacent to or on a substrate. Substrates may comprise, for example, one or more of iron, chromium, nickel, silicon, vanadium, titanium, boron, tungsten, aluminum, molybdenum, cobalt, manganese, zirconium, and niobium, oxides thereof, nitrides thereof, sulfides thereof, or any combination thereof. A substrate may be a steel substrate. A metal layer may be deposited via, for example, roll coating, vapor deposition, slurry deposition, or electrochemical deposition.

The present disclosure provides systems and methods for depositing a metal layer adjacent to or on a substrate. Substrates may comprise, for example, one or more of iron, chromium, nickel, silicon, vanadium, titanium, boron, tungsten, aluminum, molybdenum, cobalt, manganese, zirconium, and niobium, oxides thereof, nitrides thereof, sulfides thereof, or any combination thereof. A substrate may be a steel substrate. A metal layer may be deposited via, for example, roll coating, vapor deposition, slurry deposition, or electrochemical deposition.

The present disclosure provides methods for forming a metal layer adjacent to a substrate, comprising providing a substrate comprising carbon at a concentration of at least about 0.001 wt % and one or more of silicon, manganese, titanium, vanadium, aluminum and nitrogen, and depositing a first layer comprising a metal adjacent to the substrate. Next, the first layer and the substrate may be subjected to annealing under conditions that are sufficient to generate a second layer from the first layer adjacent to the substrate. The second layer may comprise the carbon and the metal as a metal carbide.

A process includes applying a slurry to a surface of a metallic article to produce a slurry film on the surface. The slurry is composed of a liquid carrier, chromium and aluminum, and an agent that is reactive with the chromium and aluminum to form intermediary compounds. The article and slurry film are then thermally treated at an activation temperature at which the agent reacts with the chromium and aluminum to form the intermediary compounds. The intermediary compounds deposit the chromium and aluminum on the surface. The thermal treating also diffuses the chromium and aluminum into a sub-surface region of the article such that the sub-surface region becomes enriched with chromium and aluminum.

A process includes applying a slurry to a surface of a metallic article to produce a slurry film on the surface. The slurry is composed of a liquid carrier, chromium and aluminum, and an agent that is reactive with the chromium and aluminum to form intermediary compounds. The article and slurry film are then thermally treated at an activation temperature at which the agent reacts with the chromium and aluminum to form the intermediary compounds. The intermediary compounds deposit the chromium and aluminum on the surface. The thermal treating also diffuses the chromium and aluminum into a sub-surface region of the article such that the sub-surface region becomes enriched with chromium and aluminum.