An aluminum member includes: a base material made of aluminum or an aluminum alloy; and an anodized coating including a barrier layer on a surface of the base material and a porous layer on the barrier layer, wherein the anodized coating contains phosphorus (P) and sulfur (S), and has a thickness of 100 ?m or less, and, in a depth direction heading from a surface of the anodized coating toward the base material, a depth providing a maximum content of S in a region situated at a depth of 500 nm or more from the surface of the anodized coating is larger than a depth providing a maximum content of P, and an inequality (the maximum content of S)>(the maximum content of P) holds.

A process of making a dense, cohesive and uniform aluminum oxide coating on a metallic substrate includes electrodepositing polynuclear aluminum oxide hydroxide clusters from a polynuclear aluminum oxide hydroxide cluster solution on a metallic substrate to form a precursor coating, and post-treating the precursor coating to form a final aluminum oxide coating on the metallic substrate.

A process of making a dense, cohesive and uniform aluminum oxide coating on a metallic substrate includes electrodepositing polynuclear aluminum oxide hydroxide clusters from a polynuclear aluminum oxide hydroxide cluster solution on a metallic substrate to form a precursor coating, and post-treating the precursor coating to form a final aluminum oxide coating on the metallic substrate.

Methods for treating a substrate are disclosed. The substrate is deoxidized and then immersed in an electrodepositable pretreatment composition comprising a lanthanide series element and/or a Group IIIB metal, an oxidizing agent, and a metal-complexing agent to deposit a coating from the electrodepositable pretreatment composition onto a surface of the substrate. Optionally, the electrodepositable pretreatment composition may comprise a surfactant. A coating from a spontaneously depositable pretreatment composition comprising a Group IIIB and/or Group IVB metal may be deposited on the substrate surface prior to electrodepositing a coating from the electrodepositable pretreatment composition. Following electrodeposition of the electrodepositable pretreatment composition, the substrate optionally may be contacted with a sealing composition comprising phosphate and a Group IIIB and/or IVB metal. Substrates treated according to the methods also are disclosed.

Methods for treating a substrate are disclosed. The substrate is deoxidized and then immersed in an electrodepositable pretreatment composition comprising a lanthanide series element and/or a Group IIIB metal, an oxidizing agent, and a metal-complexing agent to deposit a coating from the electrodepositable pretreatment composition onto a surface of the substrate. Optionally, the electrodepositable pretreatment composition may comprise a surfactant. A coating from a spontaneously depositable pretreatment composition comprising a Group IIIB and/or Group IVB metal may be deposited on the substrate surface prior to electrodepositing a coating from the electrodepositable pretreatment composition. Following electrodeposition of the electrodepositable pretreatment composition, the substrate optionally may be contacted with a sealing composition comprising phosphate and a Group IIIB and/or IVB metal. Substrates treated according to the methods also are disclosed.

A method for passivating a metal surface of a light-weight metal part is disclosed, wherein a conversion layer is applied to the surface of the light-weight metal part in a passivation step. A passivation step is carried out wherein an aqueous passivation solution is used to create a calcium phosphate-containing conversion layer (5) on the metal surface of the part, said conversion layer comprising oxides and hydroxides from the material of the part and from the passivation solution and containing amino acids.

A method for producing a corrosion resistant metal substrate and corrosion resistant metal substrate provided thereby. The method involves forming a plated substrate including a metal substrate provided with a nickel layer or with a nickel and cobalt layer followed by electrodepositing a molybdenum oxide layer from an aqueous solution onto the plated substrate, which is subsequently subjected to an annealing step in a reducing atmosphere to reduce the molybdenum oxide in the molybdenum oxide layer to molybdenum metal in a reduction annealing step and to form a diffusion layer which contains nickel and molybdenum, and optionally cobalt.

A method for producing a corrosion resistant metal substrate and corrosion resistant metal substrate provided thereby. The method involves forming a plated substrate including a metal substrate provided with a nickel layer or with a nickel and cobalt layer followed by electrodepositing a molybdenum oxide layer from an aqueous solution onto the plated substrate, which is subsequently subjected to an annealing step in a reducing atmosphere to reduce the molybdenum oxide in the molybdenum oxide layer to molybdenum metal in a reduction annealing step and to form a diffusion layer which contains nickel and molybdenum, and optionally cobalt.

This disclosure provides systems and methods for improved electro-enhancement of surfaces of workpieces. The systems and methods can include immersing a metal workpiece in a salt bath and applying a time-varying electric current that has periods of high current with periods of lower current between. The systems and methods provide borided metal workpieces that contain preferred borides on the surface and lack less preferred borides. For example, the systems and methods can provide borided steel having Fe.sub.2B and substantially lacking FeB on the surface.

This disclosure provides systems and methods for improved electro-enhancement of surfaces of workpieces. The systems and methods can include immersing a metal workpiece in a salt bath and applying a time-varying electric current that has periods of high current with periods of lower current between. The systems and methods provide borided metal workpieces that contain preferred borides on the surface and lack less preferred borides. For example, the systems and methods can provide borided steel having Fe.sub.2B and substantially lacking FeB on the surface.