Method of surface marking a mechanical part with a predefined graphical representation visible to the naked eye
View Patent ↗The invention relates to a method of surface marking a mechanical part with a predefined graphical representation, the method comprising using a laser source to apply a single laser pulse to an outside surface of a part for marking, with a mask being interposed between the laser source and the outside surface of the part, the mask having a predefined graphical representation, and the laser pulse having power flux density of at least 20 MW/cm 2 and a duration less than or equal to 100 ns.
1. A method of surface marking a mechanical part with a predefined graphical representation, the method comprising:
using a laser source to apply only a single laser pulse to an outside surface of the mechanical part for marking with a mask being interposed between the laser source and the outside surface of the mechanical part, the mask having a predefined graphical representation, and the single laser pulse having power flux density of at least 20 MW/cm 2 and a duration less than or equal to 100 ns so that an imprint left in the outside surface of the part is less than 1 μm in depth,
wherein the outside surface of the part is directly in contact with ambient atmosphere when the single laser pulse is applied.
2. The method according to claim 1 , wherein a focusing lens is interposed between the laser source and the mask.
3. The method according to claim 1 , wherein the laser source is an Nd-YAG laser.
4. The method according to claim 1 , wherein the single laser pulse has an impact diameter of at least 0.5 mm.
5. The method according to claim 1 , wherein, when the mechanical part for marking is made of metal, and the power flux density of the single laser pulse lies in a range of 0.04 GW/cm 2 to 0.55 GW/cm 2 .
6. The method according to claim 1 , wherein, when the mechanical part for marking is made of composite material comprising carbon fibers and an epoxy matrix, and the power flux density of the single laser pulse lies in a range of 0.15 GW/cm 2 to 2 GW/cm 2 .
7. The method according to claim 1 , wherein, when the mechanical part for marking is made of ceramic, and the power flux density of the single laser pulse lies in a range of 0.10 GW/cm 2 to 0.34 GW/cm 2 .
8. The method according to claim 1 , further comprising interposing an opaque mask between the laser source and the outside surface of the mechanical part, the opaque mask having a plurality of color gradations so as to obtain multi-contrast marking of the part.
9. The method according to claim 1 , wherein the mechanical part is a fan blade, a turbine blade, or a compressor blade of an aviation turbine engine.
10. The method according to claim 5 , when the mechanical part for marking is made of nickel, and the power flux density of the single laser pulse lies in a range of 0.10 GW/cm 2 to 0.52 GW/cm 2 .
11. The method according to claim 5 , when the mechanical part for marking is made of aluminum, and the power flux density of the single laser pulse lies in a range of 0.20 GW/cm 2 to 0.55 GW/cm 2 .
12. The method according to claim 5 , when the mechanical part for marking is made of steel, and the power flux density of the single laser pulse lies in a range of 0.10 GW/cm 2 to 0.50 GW/cm 2 .