Research On Key Technology Of Laminated-object Manufacturing Of High Voltage Inducing Weak Arc Discharge Deposition

Micro EDM is a micro scale 3D structure machining method of using high electrode wear to make metal material deposition and growth.According to the deficiencies of weak discharge energy leading less electrode material removal amount,small discharge gap affecting the deposition quality in micro EDM,this paper proposes.a new EDM deposition method that high voltage pulse and low voltage DC are combined to form high voltage inducing low voltage weak arc discharge.High voltage spark-over the interelectrode dielectric forming plasma discharge channel in a large gap,then induces the formation of plasma discharge channel to melt the electrode fully.The melted electrode material transfers to the workpiece and combines with the workpiece surface forming deposition layers.Through the scanning of two-dimensional plane,the deposition and growth of metal materials are realized on demand,and the micro three dimensional solid structure is gradually formed on the workpiece.(1)The process of high voltage discharge alone and high voltage inducing low voltage discharge was analyzed.The discharge experiments of two discharge modes were carried out with single crystal silicon wafer as working piece,copper(the diameter are 500?m and200?m)as electrode,The results show that under proper conditions,the high voltage induces low voltage with strong current can realize the lager gap discharge machining under the proper condition,which proved that the method is feasible.The experimental platform of high voltage inducing low voltage discharge was set up.(2)The temperature field of electrode and workpiece were simulated under high voltage discharge alone and high voltage inducing low voltage discharge.According to the simulation results,the parameter selection range of high voltage inducing low voltage discharge is determined,which provides guidance for the selection of electrical parameters in the next experiment.(3)High voltage inducing low voltage discharge deposition experiments were carried out with monocrystalline silicon wafer as workpiece and copper as electrode,including single point in situ discharge deposition,multi-points continuous multilayers deposition,etc.The technical rules were summarized.Finally,the multilayers deposition experiments with complex trajectories were carried out according to the best electrical parameters obtained from previous experiments.The results show that the deposition layers are uniform,compact,and the morphology and quality are better than that of micro EDM deposition.(4)The feasibility of high voltage inducing low voltage discharge with stainless steel as workpiece and copper as electrode was studied under larger low voltage current.The single point in situ deposition experiment shows that as the increase of discharge time,the deposition point is thicker,and the deposition layers do not collapse,which proves the feasibility of the method.At the same time,the experimental results show that the selection of electrical parameters in the larger current arc discharge,the relationship between the size of the deposition point and the electrical parameters need further studies.