Study Of Micro Blanking Based On The Effect Of Laser Shock Wave

In this dissertation,a micro blanking technology(LSMB,laser shock micro blanking)based on the effect of laser shock wave was proposed.Using the incident laser as a flexible punch,the precise micro blanking of the SUS304 stainless steel workpiece was successfully realized.The specific work of the dissertation included:(1)The LSMB experiment of SUS304 stainless steel was carried out.The influence of different process parameters(laser energy,aperture of blank holder,thickness of blank holder,thickness of workpiece)on the blanking quality(including dimension error,section morphology and the deformation depth of flushing)was studied.The experimental results showed that with the increase of the laser energy and the aperture of blank holder,the dimension error of workpiece and the deformation depth of flushing increased,proportion of the burnish zone decreased,proportion of the fracture zone increased and the number of burrs increased,namely the overall section quality decreased.When thickness of the blank holder was 1000?m,the dimension error of workpiece and the deformation depth of flushing was minimum,proportion of the burnish zone was maximum,and proportion of the fracture zone was minimum.The overall section quality was the best.(2)Using ABAQUS software,the finite element model of LSMB was established by explicit dynamic analysis,and the dynamic response process of the workpiece under the load was analyzed.The dynamic fracture process of the workpiece under LSMB was mastered by the analysis of the velocity variation of key points near the cutting edge and the time history curves of direct stress and shearing stress.The results showed that with the increase of the impact load,the velocity of central node of the workpiece increased gradually,and the workpiece would break when the load increased to a certain degree.With the increase of the spot diameter,the relative velocity of the workpiece on internal and external sides of the blade increased gradually,and the external reverse deformation increased gradually.When the relative velocity was suitable,the workpiece would break.When the relative velocity was too large,the workpiece would not break.With the increase of the impact load(the spot diameter,the thickness of workpiece),the section quality became worse.The reason was that with the increase of the impact load(the spot diameter,the thickness of workpiece),the direct stress of the workpiece gradually increased in X direction and the shearing stress gradually decreased in Z direction.The simulation results were in good agreement with the experimental results.(3)SUS304 stainless steel foil were heat-treated to obtain materials with different grain sizes.The influence of size effect on the blanking quality was studied.The experimental results showed that with the increase of the grain size,the size error and the deformation depth of flushing increased,while proportion of the burnish zone decreased,and proportion of the fracture zone and the number of burrs increased,namely the overall section quality decreased.At the same time,the unevenness of the cross section stratification became significant.The main reason was that with the increase of grain size,the coordination deformation ability of grain decreased.This study provided a new way for the manufacture of micro components(especially micro porous parts)and laid a theoretical foundation.