Research On The Key Technology Of Laser Processing Of Undevelopable Surface

At present,the communication means are complex,the electromagnetic wave types in space are complex,and the rapid development of electronic information warfare requires further improvement of the special electromagnetic performance of each equipment.As a kind of structure with wave selection and filtering characteristics and without affecting the aerodynamic characteristics of aircraft,frequency selection surface is a good solution to improve the special electromagnetic performance of equipment.Therefore,it is imperative to propose a high precision,high efficiency and low cost frequency selective surface(FSS)manufacturing technology.This paper aims at the problem of low efficiency and inconsistent quality of large scale non developable surfaces such as frequency selection on fairing.The research is made from three aspects: processing principle,machining trajectory planning and process parameters.Firstly,the laser processing system is used to work with servo motion mechanism to process efficiently.The processing speed of the galvanometer laser system is three to five times higher than that of the mechanical system.The key technology of the non developable surface processing is proposed by using the laser optical path inversion and the laser focal depth.Secondly,according to the processing principle and process requirements,the platform of laser processing of functional surface is built.Linear motor is used as driving module to make the accuracy of repeated positioning less than 0.01 mm.The mechanical motion speed can reach500mm/s,and the scanning speed of laser beam can reach 8000 mm / s.It can realize the processing of parts within 1000 mm * 500 mm * 500 mm.Finally,the process tests were carried out on the three different coating materials,namely aluminum,copper and silver,double bending cover plate and conical rotary body.The processing quality of FSS unit was observed by microscope,and the relationship between peak power,filling density,delay parameter and aluminum coating quality was discussed by quantitative characterization of removal rate and distortion rate.The relationship between the processing linewidth and repetition frequency and scanning speed was also explored to realize the laser process with a linewidth of 0.0072 mm.The experimental results show that the manufacturing of more than 100000 FSS units on the surface of double bending and rotary parts is realized by optimizing the processing parameters,and the processing quality is consistent.It can be used for the high quality processing of FSS made of aluminum,copper and silver,which can provide reference for other similar research and practical application.