There is disclosed a functional lamellar particle including an unconverted portion of the lamellar particle, wherein the unconverted portion includes a first metal, a converted portion of the lamellar particle disposed external to a surface of the unconverted portion, wherein the converted portion includes a chemical compound of the first metal; and a functional coating disposed external to a surface of the converted portion.

Disclosed is a substrate pretreatment system, comprising (a) an activating rinse for treating at least a portion of a substrate comprising a dispersion of metal phosphate particles having a D.sub.90 particle size of no greater than 10 μm, wherein the metal phosphate comprises divalent or trivalent metals or combinations thereof; and (b) a pretreatment composition for treating at least a portion of the substrate treated with the activating rinse, comprising zinc ions and phosphate ions, wherein the pretreatment composition is substantially free of nickel. Methods of treating a substrate with the substrate pretreatment system also are disclosed. Substrates treated with the substrate pretreatment system also are disclosed.

Disclosed is a substrate pretreatment system, comprising (a) an activating rinse for treating at least a portion of a substrate comprising a dispersion of metal phosphate particles having a D.sub.90 particle size of no greater than 10 μm, wherein the metal phosphate comprises divalent or trivalent metals or combinations thereof; and (b) a pretreatment composition for treating at least a portion of the substrate treated with the activating rinse, comprising zinc ions and phosphate ions, wherein the pretreatment composition is substantially free of nickel. Methods of treating a substrate with the substrate pretreatment system also are disclosed. Substrates treated with the substrate pretreatment system also are disclosed.

A system and a method for selectively coating a substrate includes a removable mask including a magnetic member having a first surface contour shaped to conform to the outside surface of the substrate and a magnetizable member having a second surface contour shaped to conform to the inside surface of the substrate. The method for coating the substrate includes magnetically coupling a removable mask to at least one surface of the substrate; forming a coating of a coating material on the at least one surface of the substrate with the magnetically coupled removable mask using a bath containing the coating material; and selectively decoupling the removable mask from the at least one coated surface to reveal a portion of the coated surface without the coating.

A system and a method for selectively coating a substrate includes a removable mask including a magnetic member having a first surface contour shaped to conform to the outside surface of the substrate and a magnetizable member having a second surface contour shaped to conform to the inside surface of the substrate. The method for coating the substrate includes magnetically coupling a removable mask to at least one surface of the substrate; forming a coating of a coating material on the at least one surface of the substrate with the magnetically coupled removable mask using a bath containing the coating material; and selectively decoupling the removable mask from the at least one coated surface to reveal a portion of the coated surface without the coating.

The present invention is directed to a particle having a chemical conversion coating on at least a portion of the particle surface. The present invention is further directed to a coated substrate comprising: (a) a surface that has been contacted with a particle having a chemical conversion coating on at least a portion of the particle surface such that at least some portion of the substrate becomes treated with the conversion coating.

The present invention is directed to a particle having a chemical conversion coating on at least a portion of the particle surface. The present invention is further directed to a coated substrate comprising: (a) a surface that has been contacted with a particle having a chemical conversion coating on at least a portion of the particle surface such that at least some portion of the substrate becomes treated with the conversion coating.

A method of inhibiting corrosion of duplex stainless steel by aqueous acidic solution, comprises carrying out a preliminary treatment which is passivation of the steel while exposing the steel to a first aqueous acidic solution containing at least one organic corrosion inhibitor able to adsorb to a steel surface, so as to deposit a passivating and corrosion inhibiting film on the steel surface; and thereafter during a second period of time exposing the steel to a second aqueous acidic solution different from the first aqueous acidic solution and also containing at least one organic corrosion inhibitor able to adsorb to a steel. The second aqueous acidic solution maintains the film on the steel surface, such that weight loss through corrosion in the second period of time is lower than the weight loss which would be observed with the same second aqueous acidic solution but without carrying out the preliminary treatment.

A method of inhibiting corrosion of duplex stainless steel by aqueous acidic solution, comprises carrying out a preliminary treatment which is passivation of the steel while exposing the steel to a first aqueous acidic solution containing at least one organic corrosion inhibitor able to adsorb to a steel surface, so as to deposit a passivating and corrosion inhibiting film on the steel surface; and thereafter during a second period of time exposing the steel to a second aqueous acidic solution different from the first aqueous acidic solution and also containing at least one organic corrosion inhibitor able to adsorb to a steel. The second aqueous acidic solution maintains the film on the steel surface, such that weight loss through corrosion in the second period of time is lower than the weight loss which would be observed with the same second aqueous acidic solution but without carrying out the preliminary treatment.

The invention relates to a process for producing a corrosion-inhibiting coating for substrates having a surface consisting of zinc, magnesium, aluminum or one of their alloys, wherein the surface to be treated is brought into contact in direct succession with two aqueous treatment solutions containing chromium(III) ions, metal ions of the substrate surface to be treated and at least one complexing agent. The first treatment solution has a pH in the range from 1.0 to 4.0, while the second treatment solution has a pH of from 3.0 to 12.0. The process of the invention produces a smaller amount of wastewater polluted with heavy metals.