Experimental Study And Numerical Simulation Of Low-Pressure Jet Assisted Laser Etching

Low-pressure jet assisted laser etching technology is a newer composite processing based on the tradition and it has very important practical significance to deeply study it.It can effectively improve the processing surface defects of more micro-cracks and slag for hard and brittle materials,at the same time,it can also improve the product's pass rate and processing quality.Therefore,the basic behavior and characteristics of material transfer during low-pressure jet assisted laser etching are analyzed by theoretical analysis,experimental research and numerical calculation and the selection and optimization method of processing parameters are studied.The main research works are as follows:1.The law of energy variation in low-pressure jet assisted laser etching process is givenThe combined effect of low-pressure jet and laser beam on the workpiece is studied and the low-pressure jet on the workpiece cooling and impact are analyzed.The relationship between the jet velocity and the surface heat transfer coefficient is introduced.When the jet is sprays at a certain angle to the machined surface,the water hammer pressure formula and the stagnation pressure formula are derived.The law of energy changes and the effects of the low-pressure jet on the composite process were researched.Thus,the reference formularies for the initial injection velocity of the low-pressure jet at the nozzle outlet can be obtained.2.A low-pressure jet-assisted laser etching experiment platform is designed systematically and builtThe idea is put forward for the selection of the laser processing system and the low-pressure jet system design and the energy loss of the liquid flow system in the composite etching test apparatus is fully analyzed.The Bernoulli energy equation at the necking section of the hydraulic pipe is established and the expression of the total energy loss of the test pipeline system is deduced.The etching test platform is systematically designed and constructed.3.The processing mechanism of low-pressure jet assisted laser etching has been enriched and improvedThe influence of the process parameters on the etching effect is analyzed,including laser processing and low-pressure jet impact;The process of composite etching is studied by using a low-pressure jet assisted laser processing test platform.The effects of different process parameters on the etching results are discussed in detail.The procedure for optimizing processing parameters by the orthogonal test is put forward.The basic processing rules of low-pressure jet assisted laser etching processing technology are Analyzed and summarized.Test results show that the optimal processing scheme can be obtained quickly.4.A numerical simulation prediction method is proposed for the material removal law during low-pressure jet assisted laser etchingThe heat conduction equation for composite etching is deduced and the finite element model is correspondingly established;The prediction study on the regularity of the variation of the cross-sectional shape is carried out by observing the simulation results under different process parameters.The impact process of the low-pressure jet is simulated by SPH(Smoothed Particle Hydrodynamics)-FEM(finite element method)coupling algorithm.The erosive effect on the surface is studied under different process parameters.The comparative analysis shows that the numerical simulation results of composite etching are in good agreement with the actual experimental results.