Fabrication method of surface array microstructure by laser etching based on the shape of curved workpiece

Abstract

The invention provides a laser etching preparation method for a surface array microstructure on the basis of a curved surface workpiece appearance. The method includes the steps that the free curved surface workpiece appearance to be processed is measured by the adoption of a reverse engineering method in a modeling mode, and design graph layout of the surface array microstructure is conducted on the basis of a reconstructed curved surface model; then, laser etching processing path planning is conducted on a design graph, the spatial orientation of a laser processing head relative to a free curved surface workpiece is adjusted according to a tangent plane where a processing path is located, a geometric center point and a corresponding outer-normal vector, laser beams are reflected to the free curved surface workpiece in the normal direction, and laser etching processing is conducted on geometric lines one by one. According to the method, it can be effectively guaranteed that the focus of the laser beams is located on the surface of the free curved surface workpiece all the time in the processing procedure or a certain defocusing distance exists between the focus of the laser beams and the surface of the free curved surface workpiece, a brand new accurate focusing laser processing method is provided, layout and processing errors of the surface array microstructure graph are completely eliminated, and accuracy and stability of laser etching processing technical quality are ensured.

Description

technical field [0001] The invention belongs to the technical field of laser processing, and in particular relates to a surface array microstructure laser etching preparation method based on the shape of a curved workpiece. Background technique [0002] In the field of mechanical industry and electronic industry, it is often necessary to prepare array microstructures on the surface of the formed free-form surface workpiece. Microstructure refers to the tiny topological shape of the surface with a surface shape accuracy of submicron level and surface roughness of nanometer level with specific functions. The most important feature of microstructure is the functionality of its structure. For example, the surface structure of microstructure surface optical components determines the reflection, transmission or diffraction performance of light, which is convenient for optical designers to optimize the optical system, reduce weight and reduce volume. Another feature is that they g...

AI Technical Summary

Problems solved by technology

The first method is to conduct offline virtual design based on the theoretical workpiece model and then process the actual workpiece online. However, since any free-form surface workpiece has machining tolerances during the processing of its free-form surface shape, this method does not consider the actual workpiece. The error between the external dimension and the theoretical workpiece model, the processing error is large

The second method is to conduct offline virtual layout and design based on surface array microstructure graphics, and then process the actual workpiece online. There are large deviations in both layout and processing