Method for increasing laser absorption rate of high-reflectivity metal surface

Abstract

The invention discloses a method for increasing the laser absorption rate of a high-reflectivity metal surface. Firstly, the to-be-processed metal surface is pretreated, and surface dust, oil dirt andcorrosion are removed; and then, texturing is conducted on the to-be-processed metal surface through a picosecond pulse laser, the uniform texture morphology is formed, and thus the laser absorptionrate of the metal surface is increased. A parallel groove texture or a cross-shaped groove structure is processed and formed on the metal surface through 515 nm picosecond pulse green lasers, and a laser texturing technology and laser macroscopic processing are effectively combined, and thus the problem that the laser absorption rate of high-reflectivity metal is low is solved. The regular texturecan be quickly, efficiently and accurately formed on the to-be-processed metal surface and is mot limited by the shape of a workpiece, the method is suitable for various high-reflectivity metal components with the thickness being 1 mm or over, after texturing, the surface roughness is controlled to be 13 [mu]m or blow, and the influence on the surface integrity of the workpiece is small; and thetechnology is simple, the cost is low, the efficiency is high, and the surface absorption rate of the workpiece can be increased to 80% or over.

Description

technical field [0001] The invention relates to a method for improving the laser absorption rate of a high-reflection metal surface, which belongs to the technical field of laser processing. Background technique [0002] At present, compared with traditional processing methods such as TIG, high-voltage arc, and MIG, the laser beam has the characteristics of high flexibility and high energy density distribution, which makes laser processing have a series of advantages such as small heat-affected zone, small deformation, and high efficiency. The low absorptivity of highly reflective metals to laser light is an important factor hindering their industrial laser processing. The factors affecting the laser absorption rate of the workpiece mainly include the surface characteristics of the workpiece, laser wavelength, material temperature and laser power density. At present, the main methods to improve the laser absorptivity of the highly reflective metal surface are: 1) Improve th...

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Problems solved by technology

Coating corresponding light-absorbing coatings or coatings on the surface of workpieces, such as phosphating agents, graphite coatings, nickel coatings, etc., can effectively improve the absorption of laser light on the surface of the material, but the surface is rough, easy to ablate, pungent, and difficult to clean. 2) Dual-wavelength laser superimposition processing, the shorter the wavelength, the higher the laser absorption rate of the workpiece, so the short-wavelength laser loading can preheat the workpiece, and the long-wavelength laser is used for formal laser processing, which significantly improves the repetitive processing of laser processing Accuracy and processing efficiency, but there are problems such as complex laser equipment and high cost; 3) preheating treatment before workpiece processing, the absorption rate of metal to laser increases with the increase of temperature, and the processing effect of workpiece after preheating is also better, but the workpiece The preheating range will be limited by the size of the workpiece, and it is difficult to control the preheating time and laser processing technology after preheating and heat preservation

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