US 12,337,413 B2
System for shaping beam and adjusting beam energy density, and laser heat treatment process
Bin Du, Guangdong (CN); Ruotao Li, Guangdong (CN); and Yong Chang, Guangdong (CN)
Assigned to HSG LASER CO., LTD., Foshan (CN)
Filed by HSG LASER CO., LTD., Guangdong (CN)
Filed on Aug. 16, 2024, as Appl. No. 18/806,758.
Claims priority of application No. 202311547399.0 (CN), filed on Nov. 20, 2023.
Prior Publication US 2025/0162067 A1, May 22, 2025
Int. Cl. B23K 26/06 (2014.01); G02B 27/09 (2006.01)
CPC B23K 26/0643 (2013.01) [G02B 27/0944 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A system for shaping a beam and adjusting a beam energy density, comprising a laser source (1), a collimator mirror (2), a spatial light modulator (3), an X-direction mirror (5), a focusing assembly (6) and a Y-direction mirror (10), characterized in that: the spatial light modulator (3) comprises a binary grating (31) and a mask (4) which are disposed in sequence, a laser beam emitted by the laser source (1) sequentially passes through the collimator mirror (2), the spatial light modulator (3), the X-direction mirror (5), the focusing assembly (6) and the Y-direction mirror (10), the binary grating (31) is configured to change a diffraction period to shape the laser beam, the mask (4) is configured to adjust a grating density to change an energy density distribution of the laser beam, and the X-direction mirror (5) and the Y-direction mirror (10) are used for a dynamic scanning movement of the laser beam;
a thermal efficiency of the laser and an energy density model of the energy density distribution of the spot during processing are as follows:

OG Complex Work Unit Math
according to the Rosenthal equation, in Equation custom character, λ is a thermal conductivity of a material to be processed, v is a feed speed of the material, B is an absorption rate, q is a laser source power, T0 is an ambient temperature, and T is an actual temperature;
in Equation custom character, Eutilized is a lowest energy rate, ρ is a density of a material to be processed, Cp is a specific heat capacity of the material, V is a volume of the material in a processed hardened zone, Lp is heat energy required for a phase change transformation of the material, T0 is an ambient temperature, Tf is a highest temperature of the surface of the material, A3 is an upper limit temperature for material hardening, v is a scanning speed of the laser beam, and A is a cross-sectional area of the material;
in Equation custom character, H is a hardening efficiency index, ΔH is an average adding value of material hardness, A is a cross-sectional area of a material quenching surface, and Ein corresponds to an overall energy density provided.