Numerical Simulation And Experimental Study On Picosecond Laser Processing Of Carbon Fiber Reinforced Plastic

With the increasingly prominent energy and environmental problems,people have more and more production and application of lightweight materials.As a representative of lightweight materials,carbon fiber reinforced plastic(CFRP)with various advantages,are widely used in aerospace,automobile and ship,large-scale construction,chemical corrosion prevention and other fields,but CFRP also have the characteristic of difficult processing.In order to solve this problem,this paper uses picosecond laser to simulate the processing and cutting of CFRP.Picosecond laser has the characteristic of "cold working",which can greatly reduce the thermal damage area.Through the experimental platform and observation system of picosecond laser processing,the absorption of materials in the process of processing CFRP by laser heat flow model is simulated,the mechanism of material removal by picosecond laser is described,and the process of laser processing materials under different working conditions is dynamically observed.The temperature characteristics,cutting depth and surface morphology of the materials were studied and compared under three different conditions of blowing,air and vacuum,and the most suitable processing environment and processing parameters were obtained.The main research contents are as follows:(1)The situation and application scenario of picosecond laser processing technology are described,the difficulties of picosecond laser processing CFRP are introduced and the related research status at home and abroad are summarized.According to the characteristic of difficult processing of CFRP,the experimental platform and observation system of picosecond laser processing are built respectively from the hardware system design,which can realize three different environments of blowing,air and vacuum.(2)The picosecond laser heat flow model is established based on the theory of laser heat conduction.The picosecond laser heat flow model is solved by the finite element method.The laser processing temperature field is obtained.The influence of different defocusing amount on the laser temperature field is studied.The simulation and experimental results of different defocusing amount on ablation width,ablation depth and HAZ are compared.The simulation value is less than the experimental value.The result is identical.(3)The mechanism of interaction between picosecond laser and CFRP is studiedand explained.The common processing defects of picosecond laser in processing CFRP are summarized.The ablation process of material under the conditions of blowing,air and vacuum is recorded by picosecond laser processing observation system.The different phenomena in the ablation process are compared and the reasons behind the phenomenon are explained,which provides theoretical basis for the follow-up test.(4)The different properties of CFRP processed by picosecond laser were studied in three different environments,such as air blowing,air and vacuum.Under various working conditions,the temperature changes of CFRP are measured by using colorimetric pyrometer,and the cutting depth and surface morphology of CFRP are recorded with super depth of field microscope.Through analyzing changes of CFRP under different working conditions,the better processing environment and process parameters are obtained,which can well restrain the surface defects of materials.