Method and device for preparing a grinding pattern for a metallurgical sample
The invention relates to a method and a device for preparing a grinding pattern for a metallurgical sample ( 1 ), wherein, after preparing the sample ( 1 ), a thermal contrasting of the surface is carried out by laser equipment, wherein, using a USP laser ( 2 ), at least the following processing steps are carried out: cleaning (R) the surface of the sample ( 1 ) with an ablation depth of between 1 to 50 μm to reveal joining gap structures ( 300 ); contrasting (K) the cleaned surface of the sample ( 1 ) with an ablation depth between 0.5 to 20 μm to make joining structures ( 400 ) visible; laser etching (A) the contrasted surface of the sample ( 1 ) via the ablation-free creation of a thermal annealing color structure ( 500 ) and/or surface oxidation.
1 . A method for preparing a grinding pattern for a metallurgical sample ( 1 ) using an ultra-short pulse (USP) laser, the method comprising:
cleaning (R), using the USP laser, a surface of the sample ( 1 ) with an ablation depth of between 1 to 50 μm to reveal joining gap structures ( 300 );
contrasting (K), using the USP laser, the surface of the sample ( 1 ) with an ablation depth of between 0.5 to 20 μm to make joining structures ( 400 ) visible after cleaning (R); and
laser etching (A), using the USP laser, the surface of the sample ( 1 ) via an ablation-free creation of a thermal annealing color structure ( 500 ) and/or surface oxidation after contrasting (K).
2 . The method according to claim 1 , further comprising smoothing (G), using the USP laser, the surface of the sample ( 1 ) with an ablation depth of between 20 to 150 μm for leveling surfaces before the cleaning (R).
3 . The method according to claim 2 , wherein at least material-removing steps of cleaning (R) and contrasting (K) are carried out in accordance with a uniformly linear ablation pattern.
4 . The method according to claim 3 , wherein the uniformly linear ablation pattern with at least 6 hatching directions is applied at an angle of 40° to 50° per ablation.
5 . The method according to claim 4 , wherein the uniformly linear ablation pattern with 8 hatching directions is applied at an angle of 45° per ablation.
6 . The method according to claim 1 , wherein the USP laser ( 2 ) for laser etching (A) is operated at a constant wavelength λ in a range between 1020 nm to 1040 nm, as well as at a pulse width (t P ) of ≤10 ps.
7 . The method according to claim 6 , wherein the USP laser ( 2 ) for laser etching (A) is operated at a constant wavelength λ of 1030 nm +/−3 nm.
8 . The method according to claim 1 , wherein at least material-removing steps of cleaning (R) and contrasting (K) are carried out in accordance with a uniformly linear ablation pattern.
9 . The method according to claim 8 , wherein the uniformly linear ablation pattern with at least 6 hatching directions is applied at an angle of 40° to 50° per ablation.
10 . The method according to claim 9 , wherein the uniformly linear ablation pattern with 8 hatching directions is applied at an angle of 45° per ablation.
11 . A device for performing the multiple step method according to claim 1 , at least comprising the USP laser ( 2 ) for generating a laser beam ( 3 ), a beam deflection unit ( 4 ) for moving and focusing the laser beam ( 3 ) relative to the surface of the sample ( 1 ), a sample clamping unit ( 5 ) for positioning the sample ( 1 ) relative to the beam deflection unit ( 4 ), an electronic control unit ( 6 ) for coordinated control of these units in accordance with the method step (G; R; K; A) to be performed.
12 . The device according to claim 11 , wherein a focus shifter ( 10 ) for positioning a laser focus along an optical Z-axis is arranged between the USP laser ( 2 ) and the beam deflection unit ( 4 ).
13 . The device according to claim 12 , wherein a beam width unit ( 11 ) for increasing a cross section of the laser beam is arranged between the USP laser ( 2 ) and the focus shifter ( 10 ).
14 . The device according to claim 11 , wherein the beam deflection unit ( 4 ) comprises a dual-axis mirror system ( 12 ) for controlling the laser beam ( 3 ) for material processing along the surface of the sample ( 1 ) to be processed according to an ablation pattern.
15 . The device according to claim 11 , wherein the sample clamping unit ( 5 ) is configured to position the sample ( 1 ) to be processed spatially opposite the beam deflection unit ( 4 ) along axes (x, y, z).