US 12,257,600 B2
Aluminum surface treatment method to increase adhesion with polyurethane coating
Arnas Zemaitis, Vilnius (LT); Deividas Cereska, Vilnius (LT); and Gabrielius Kontenis, Vilnius (LT)
Assigned to Femtika, UAB, Vilnius (LT)
Filed by Femtika, UAB, Vilnius (LT)
Filed on Oct. 19, 2021, as Appl. No. 17/504,548.
Prior Publication US 2023/0121045 A1, Apr. 20, 2023
Int. Cl. B23K 26/352 (2014.01); B05D 3/06 (2006.01); B23K 26/00 (2014.01); B23K 26/0622 (2014.01); B23K 26/60 (2014.01); B23K 103/10 (2006.01)
CPC B05D 3/06 (2013.01) [B23K 26/0006 (2013.01); B23K 26/0622 (2015.10); B23K 26/355 (2018.08); B23K 26/60 (2015.10); B05D 2202/25 (2013.01); B05D 2503/00 (2013.01); B23K 2103/10 (2018.08)] 11 Claims
OG exemplary drawing
 
1. A method for aluminum surface treatment to achieve increased adhesion with paint, the method comprising:
analyzing physical and chemical properties of an aluminum material and of a polyurethane coating; wherein the melting and boiling points, thermal capacity, and thermal conductivity are provided by material manufacturer or found in materials catalogs; and wherein the chemical properties of ionization potential, chemical stability, oxidation levels, chemical composition, and reactivity with other chemicals are provided by manufacturer or found in material catalogs;
measuring roughness of the aluminum material surface with a profilometer;
removing foreign matter from the aluminum surface by chemical and physical means;
selecting a dimple pattern based on the chemical and physical properties of the aluminum surface and based on the chemical and physical properties of the polyurethane coating;
adjusting parameters of a femtosecond laser system, wherein the system is configured to produce a light wavelength between 500 and 1070 nm, and wherein the parameters to be adjusted comprise:
pulse repetition rate, wherein the pulse repetition rate is within the range of 1 to 50000 kHz;
average power, wherein the average power is within the range of 0.1 to 300 W;
polarization;
pulse duration;
drilling time;
scanning speed; and
focus diameter on the aluminum surface; and
wherein a required energy output of the femtosecond laser system and the adjusted parameters are configured to produce the selected dimple pattern on the aluminum surface;
irradiating of the aluminum surface with the set of adjusted parameters for the femtosecond laser system to achieve the selected dimple pattern of the aluminum surface.