Basic Research On Laser Cutting Technology Of Copper-Steel Laminated Plate By Pretreatment

It is a common measure to use fiber laser cutting machine for the processing and preparation of precision parts such as slit grating.At present,the types of engineering materials are more and more abundant,and its high reflection and high thermal conductivity make it more difficult to cut by laser.The material used in this study is copper-steel laminate,which faces the problems of low laser absorptivity,wide slit and large heat affected zone.Therefore,the laser pretreatment method is proposed,the processing principle analysis,simulation analysis and pretreatment experiment verification are carried out,and the surface quality of the pretreatment is detected.Based on the pretreatment,the cutting experiment is carried out,and the slit grating which meets the size and quality requirements is successfully prepared.The main contents are as follows:(1)Study on laser absorptivity and shallow melting mechanism of copper steel laminates.In order to solve the problem of low absorptivity of laser,and a large number of laser beams are reflected back to the laser head,which breaks the shutter and even damages the laser.The main parameters that affect the absorption of laser energy are studied by the method of formula derivation.The study found that the surface roughness,processing temperature,laser wavelength and the conductivity of the material itself are all important factors affecting the laser absorption of the material.The pretreatment method changes the conditions to meet the processing requirements.(2)Simulation analysis of shallow melting under the action of laser and material.In this paper,the transverse combustion and shallow melting problems caused by laser on the material surface are simulated and analyzed.COMSOL was used to study the pretreatment.The results show that the surface temperature of the laser pretreated material conforms to the transverse combustion theory,and the temperature range meets the needs of shallow melting.The simulation results show that the phenomenon of combustion extinction and reburning does exist in the process of laser interaction with materials,and the simulation and principle are consistent with the experimental results.(3)Parameter analysis and modification effect detection of laser pretreatment for copper steel laminates.Aiming at the surface morphology,composition and effect of laser pretreatment,single factor experiments such as laser power,scanning speed,gas pressure and complete experiments of two factors and three levels were designed.The composition of elements and the change of roughness in the shallow melting zone were detected by using oxide area ratio and experimental instruments.The results show that there is a linear relationship between the proportion of oxide area in the pretreatment area and the scanning parameters,the roughness value increases after scanning,and the mechanical properties are significantly improved.(4)Based on the pretreatment of laser cutting effect comparison,quality analysis and slit grating trial production.Aiming at the problem of quality effect of laser cutting copper steel laminate,a comparative experiment was carried out.It was found that the quality of cutting seam obtained by the pretreatment method was better than that of the contrast piece.Moreover,the pretreatment method is successfully used in the trial production of the slit grating parts,and the prepared parts meet the surface and size quality requirements.The research in this paper provides an effective method for 1064 nm fiber laser cutting copper steel laminate to prepare slit grating,and the processing process and quality effect are verified by experiments,which provides data and material parameters for further research on cutting quality and laser material interaction theory.