A process for the corrosion protection of metals such as magnesium, aluminium or titanium, where at least two steps are used, including both plasma electrolytic oxidation and chemical passivation. The combination of these two processing steps enhances the corrosion resistance performance of the surface beyond the capability of either of the steps in isolation, providing a more robust protection system. This process may be used as a corrosion protective coating in its own right, or as a protection-enhancing pre-treatment for top-coats such as powder coat or e-coat. When used without an additional top-coat, the treated parts can still retain electrical continuity with and adjoining metal parts. Advantages include reduced cost and higher productivity than traditional plasma-electrolytic oxidation systems, improved corrosion protection, greater coating robustness and electrical continuity.

A process for the corrosion protection of metals such as magnesium, aluminium or titanium, where at least two steps are used, including both plasma electrolytic oxidation and chemical passivation. The combination of these two processing steps enhances the corrosion resistance performance of the surface beyond the capability of either of the steps in isolation, providing a more robust protection system. This process may be used as a corrosion protective coating in its own right, or as a protection-enhancing pre-treatment for top-coats such as powder coat or e-coat. When used without an additional top-coat, the treated parts can still retain electrical continuity with and adjoining metal parts. Advantages include reduced cost and higher productivity than traditional plasma-electrolytic oxidation systems, improved corrosion protection, greater coating robustness and electrical continuity.

One example provides a method of manufacturing. The method comprises oxidizing, using plasma, a first surface of a substrate comprising a metal-material. The method further comprises cutting into the substrate through the oxidized first surface to expose a non-oxidized second surface of the substrate, the second surface not parallel to the first surface. The method further comprises disposing, using electrophoretic deposition, a coating layer over the exposed second surface to form an article having the oxidized first surface and the coated second surface.

There is disclosed a method for producing corrosion and erosion-resistant mixed oxide coatings on a metal substrate, as well as a mixed oxide coating itself. A surface of the substrate metal is oxidized and converted into a first coating compound comprising a primary oxide of that metal by a plasma electrolytic oxidation (PEO) process. One or more secondary oxide compounds comprising oxides of secondary elements not present in conventional alloys of the substrate metals at significant (>2 wt %) levels are added to the first oxide coating. The source of the secondary element(s) is at least one of: i) a soluble salt of the secondary element(s) in the electrolyte; ii) an enrichment of the surface of the substrate metal with secondary element(s) prior to PEO processing; and iii) a suspension of the secondary element(s) or oxide(s) of the secondary element(s) applied to the oxide of the metal after this has been formed by the PEO process.

There is disclosed a method for producing corrosion and erosion-resistant mixed oxide coatings on a metal substrate, as well as a mixed oxide coating itself. A surface of the substrate metal is oxidized and converted into a first coating compound comprising a primary oxide of that metal by a plasma electrolytic oxidation (PEO) process. One or more secondary oxide compounds comprising oxides of secondary elements not present in conventional alloys of the substrate metals at significant (>2 wt %) levels are added to the first oxide coating. The source of the secondary element(s) is at least one of: i) a soluble salt of the secondary element(s) in the electrolyte; ii) an enrichment of the surface of the substrate metal with secondary element(s) prior to PEO processing; and iii) a suspension of the secondary element(s) or oxide(s) of the secondary element(s) applied to the oxide of the metal after this has been formed by the PEO process.

A method of manufacturing a metal material is provided. The method includes steps of manufacturing a metal material in which oxygen atoms are dispersed, and forming a protective coating on a surface of the metal material by using an anode oxidation treatment, wherein the oxygen atoms in the metal material are supplied to the surface of the metal material during the anode oxidation treatment, so that the metal material and the protective coating are interface-bonded to each other substantially without pores therebetween or without an interface layer in which pores are formed, thereby improving corrosion resistance, as compared to a protective coating formed on a surface of a metal material in which oxygen atoms are not dispersed.

A method of manufacturing a metal material is provided. The method includes steps of manufacturing a metal material in which oxygen atoms are dispersed, and forming a protective coating on a surface of the metal material by using an anode oxidation treatment, wherein the oxygen atoms in the metal material are supplied to the surface of the metal material during the anode oxidation treatment, so that the metal material and the protective coating are interface-bonded to each other substantially without pores therebetween or without an interface layer in which pores are formed, thereby improving corrosion resistance, as compared to a protective coating formed on a surface of a metal material in which oxygen atoms are not dispersed.

A method of coating a medical implant with hydroxyapatite comprises steps of: (a) plasma treating said medical implant by a plasma electrolytic oxidation bath within an electrolyte; (b) hydroxyapatite coating a plasma treated medical implant in a hydrothermal pressurized reactor; (c) washing a hydroxyapatite coated medical implant; and (d) drying a washed medical implant. At least one of steps a and b further comprises a sub-step of forming crystallization seeds on a surface of said medical implant.

The present subject matter relates to techniques of electrolytic oxidation for composite materials. In an example, a method includes immersing a composite material into an electrolytic solution for electrolytic oxidation, wherein the composite material comprises a metal alloy substrate and a second substrate. The method further includes providing a predetermined voltage to the electrolytic solution after every predefined time interval, wherein the voltage triggers electrolytic oxidation of the metal alloy substrate.

The present subject matter relates to techniques of electrolytic oxidation for composite materials. In an example, a method includes immersing a composite material into an electrolytic solution for electrolytic oxidation, wherein the composite material comprises a metal alloy substrate and a second substrate. The method further includes providing a predetermined voltage to the electrolytic solution after every predefined time interval, wherein the voltage triggers electrolytic oxidation of the metal alloy substrate.