Method of surface micro-texturing with a subtractive agent

Patent metadata

Field	Value
Publication number	US-11142830-B2
Application number	US-201916270995-A
Country	US
Kind code	B2
Filing date	Feb 8, 2019
Priority date	Feb 8, 2019
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

A method of micro-texturing a surface is disclosed. The method includes printing an etchant onto a substrate surface and forming a micro-texture on the substrate surface by removing material from the substrate surface.

First claim

What is claimed is:

1. A method of micro-texturing a curved substrate surface on a skin of an aircraft, comprising:
printing an etchant onto a curved substrate surface on the skin of an aircraft by dispensing etchant droplets from an inkjet printhead mounted on a robotic arm capable of rotation around six different axes, and
forming a micro-texture on the substrate surface by removing material from the substrate surface,
wherein a size of the etchant droplets defines a dimension of the micro-texture.

2. The method of claim 1 , wherein the removing step includes dissolving material in the etchant, and removing the etchant from the substrate surface.

3. The method of claim 1 , further comprising:
painting the skin of the aircraft prior to the step of printing the etchant.

4. The method of claim 1 , wherein the forming step results in creating micro-riblets on the substrate surface.

5. The method of claim 4 , wherein the micro-riblets have a height in a range of about 15-50 microns.

6. The method of claim 1 , wherein the printhead includes one or more Drop-On-Demand (DOD) inkjet nozzles.

7. The method of claim 1 , wherein the printhead is configured for use with a portfolio of etchants.

8. The method of claim 7 , wherein each etchant of the portfolio has a different etchant strength.

9. The method of claim 1 , further comprising:
painting a decorative protective paint coat on to substantially an entire exterior skin of the aircraft prior to the printing step, the etchant being selected to form micro-riblets in the decorative protective paint coat.

10. The method of claim 9 , wherein the printing step includes etching micro-riblets primarily in designated drag-reduction zones spaced away from leading edge airfoil surfaces of the aircraft.

11. The method of claim 10 , wherein the removing step includes:
spraying a wash solution on to the painted substrate surface after a sufficient time for the etchant to form micro-riblets in the painted substrate surface of the aircraft.

12. The method of claim 1 , wherein the substrate surface is curved around multiple axes.

13. The method of claim 1 , further comprising:
acquiring data from a sensor directed at a portion of the substrate surface after the printing step,
analyzing the data to determine an extent of etching.

14. The method of claim 13 , further comprising:
adjusting the printing step based on the extent of etching determined in the analyzing step.

15. The method of claim 13 , wherein the sensor includes a camera.

16. A method of micro-texturing a curved substrate surface on a skin of an aircraft, comprising:
generating micro-riblets on the curved substrate surface by printing etchant on the substrate surface by dispensing etchant droplets from an inkjet printhead mounted on a robotic arm capable of rotation around six different axes, dissolving substrate material in the etchant, and removing the etchant from the substrate surface,
wherein a waiting period between the printing and removing steps defines a dimension of the micro-riblets.

17. The method of claim 16 , wherein the etchant is selected from a group consisting of: acids, ketones, solvents, and caustics.

18. The method of claim 16 , wherein adjacent micro-riblets are spaced by a distance in a range of about 70-100 microns.

19. The method of claim 16 , wherein the micro-riblets have a height in a range of about 15-50 microns.

20. The method of claim 16 , further comprising: painting the skin of the aircraft prior to the step of printing the etchant.

Assignees

• Boeing Co

Inventors

• Desai Raj
• Auffinger Caitlin Elizabeth
• Van Camp Conor
• Greene Edward

Classifications

• F15D1/0085

  Methods of making characteristic surfaces for influencing the boundary layer · CPC title

• C23F1/32

  Alkaline compositions (C23F1/42 takes precedence) · CPC title

• B33Y40/00

  Auxiliary operations or equipment, e.g. for material handling · CPC title

• B05C5/002

  the work consisting of separate articles (B05C5/0208 takes precedence) · CPC title

• C23F1/08 Primary

  Apparatus, e.g. for photomechanical printing surfaces (photo- mechanical reproduction G03F) · CPC title