Additive for quality determination of conversion coatings

Patent metadata

Field	Value
Publication number	US-11807779-B2
Application number	US-202117370489-A
Country	US
Kind code	B2
Filing date	Jul 8, 2021
Priority date	Oct 4, 2018
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A method of applying a trivalent chromium or chromium-free conversion coating to a metallic substrate including mixing a dye compound that interacts with electromagnetic radiation outside the human visual spectrum but not electromagnetic radiation that is within the human visual spectrum to produce an observable emission into the trivalent chromium or chromium-free conversion coating mixture to allow for inspection of the coating after applied with a correlating electromagnetic radiation source.

First claim

The invention claimed is:

1. A component comprising:
a substrate; and
a conversion coating thereon, wherein the conversion coating is colorless to human perception and comprises:
a corrosion inhibiting compound; and
a dye compound, wherein the dye compound interacts with electromagnetic radiation outside the human visual spectrum to produce an observable emission, the dye compound comprises phosphorescent molecules selected from the group consisting of strontium aluminates, lanthanide doped strontium aluminates, manganese doped strontium aluminates, and copper activate zinc sulfide;
wherein the electromagnetic radiation outside the human visual spectrum has a wavelength less than 390 nm or greater than 700 nm.

2. The component of claim 1 , wherein the substrate is selected from the group consisting of aluminum, magnesium, zinc, nickel, titanium, silver, steel, tin, and alloys thereof.

3. The component of claim 1 , wherein the dye compound contains molecules observable in the visible, infrared, or ultra violet range of the electromagnetic spectrum.

4. The component of claim 1 , wherein the dye compound emits visible light when exposed to ultra-violet electromagnetic radiation.

5. The component of claim 1 , wherein the conversion coating has a thickness of 20-500 nm.

6. A method of inspecting a conversion coating comprising:
applying electromagnetic radiation to a conversion coating comprising a non-hexavalent chromium corrosion inhibiting compound and a dye compound that interacts with electromagnetic radiation to produce an observable emission, wherein the dye compound comprises phosphorescent molecules selected from the group consisting of strontium aluminates, lanthanide doped strontium aluminates, manganese doped strontium aluminates, and copper activate zinc sulfide, wherein the conversion coating is colorless to human perception and the electromagnetic radiation has a wavelength less than 390 nm or greater than 700 nm; and
inspecting the integrity of the conversion coating with by observing emissions from the dye compound in response to the electromagnetic radiation.

7. The method of claim 6 , further comprising applying the conversion coating to a substrate and curing the conversion coating on the substrate.

8. The method of claim 6 , wherein applying electromagnetic radiation comprises inducing phosphoresce in the dye compound.

9. The method of claim 6 , wherein applying electromagnetic radiation comprises exposing the dye compound to ultra violet light to induce black light emission from the dye compound.

10. The component of claim 1 , wherein the observable emission is outside the human visible spectrum.

11. The component of claim 1 , wherein the dye compound does not alter the human perception that the conversion coating is colorless.

12. The method of claim 6 , wherein the emissions are outside the human visible spectrum and are observed with a UV or IR detector.

13. The method of claim 6 , wherein the dye compound does not alter the human perception that the conversion coating is colorless.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Emerson Sean C
• Smith Blair A
• Li Weina
• Zafiris Georgios S
• Van Hassel Bart Antonie

Classifications

• C09D5/004 Primary

  Reflecting paints; Signal paints · CPC title

• C09D5/084

  Inorganic compounds · CPC title

• C09D5/086

  Organic or non-macromolecular compounds · CPC title

• C09D5/22 Primary

  Luminous paints {(luminescent compositions C09K11/00)} · CPC title

• C09D5/32

  Radiation-absorbing paints {(protection against X-, gamma- or corpuscular radiation G21F)} · CPC title