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 forming a downhole tool comprises contacting at least one downhole structure comprising at least one metal material with a molten electrolyte comprising anhydrous sodium tetraborate. Electrical current is applied to at least a portion of the at least one downhole structure to form at least one borided downhole structure comprising at least one metal boride material. Other methods of forming a downhole tool, and a downhole tool are also described.

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.

Methods are provided for modifying a porous surface of an implantable medical device by subjecting the porous surface to a modified micro-arc oxidation process to improve the ability of the medical device to resist microbial growth, to improve the ability of the medical device to adsorb a bioactive agent or a therapeutic agent, and to improve tissue in-growth and tissue on-growth of the implantable medical device.

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.

A metal article comprises two metals, and a first hole and an oxide layer are set correspondingly on the surfaces of the two metals. To avoid the electrolytic corrosion on the interface between the two metals during the formation of the first hole, the disclosure provides a method of manufacturing the metal article. By putting a metal substrate in a first electrolyte including an etching agent and a passivating agent and applying electricity on the metal substrate, the metal article with the first hole is formed without electrolytic corrosion. The disclosure also provides a metal composite, which is formed by setting a material part in the first hole of the metal article.

A metal article comprises two metals, and a first hole and an oxide layer are set correspondingly on the surfaces of the two metals. To avoid the electrolytic corrosion on the interface between the two metals during the formation of the first hole, the disclosure provides a method of manufacturing the metal article. By putting a metal substrate in a first electrolyte including an etching agent and a passivating agent and applying electricity on the metal substrate, the metal article with the first hole is formed without electrolytic corrosion. The disclosure also provides a metal composite, which is formed by setting a material part in the first hole of the metal article.

A method of manufacturing a thermal cutting element for a surgical instrument includes manufacturing a substrate, coating at least a portion of the substrate via Plasma Electrolytic Oxidation (PEO), and disposing a heating element on at least a portion of the PEO-coated substrate. The method may further include attaching the thermal cutting element to a jaw member of a surgical instrument.

A method of manufacturing a thermal cutting element for a surgical instrument includes manufacturing a substrate, coating at least a portion of the substrate via Plasma Electrolytic Oxidation (PEO), and disposing a heating element on at least a portion of the PEO-coated substrate. The method may further include attaching the thermal cutting element to a jaw member of a surgical instrument.