Experimental Research On Double-wire Electrode EDM Grinding Of Ultra-thin Polycrystalline Diamond Slices

Polycrystalline Diamond(PCD)ultra-thin cutting discs are widely used in precise microcutting and grooving of precious semiconductor materials,magnetic materials,superconducting materials and hard and brittle materials.However,the domestic research on the processing of PCD ultra-thin cutting sheets started late,and the research is less,and only some varieties can be produced.They can replace imported products in the field of medium and low precision,and still rely on imports in the field of high precision.Research on insert machining.The hard-tomachine part of the PCD ultra-thin cutting sheet is the PCD layer,and EDM is considered to be a suitable method for processing PCD.This paper proposes a two-wire electrode EDM PCD ultra-thin cutting sheet,which can process both sides of the PCD layer at the same time and improve the processing efficiency.Firstly,the processing method of double-wire electrode EDM grinding PCD ultra-thin cutting sheet is introduced,and the forming process of PCD cutting edge is briefly analyzed.Secondly,the simulation software COMSOL is used to simulate the thermal structure coupling of single wire electrode and double wire electrode machining process.Simulation studies show that double-sided heating does not significantly warp the edges of PCD ultrasheets.Based on the analysis of ultra-thin slice machining requirements,a horizontal machining device that can realize double-wire electrode EDM grinding of ultra-thin cutting edges is built.The feasibility processing experiment was carried out using tungsten steel ultra-thin slices.The experimental results show that the double-wire electrode EDM machining scheme can realize the processing of ultra-thin slices.On the basis of the feasibility verification experiment of double-wire electrode EDM grinding ultra-thin cutting edge,the machining process planning of PCD ultra-thin cutting blade is carried out.The process of EDM PCD ultra-thin cutting sheet is divided into rough machining and finishing: rough machining uses a large discharge energy slow wire machine to erode the metal matrix of the PCD ultra-thin cutting sheet to shorten the processing time.Finishing uses a dual wire electrode to grind the PCD cutting edge.The rough machining experiment of PCD ultra-thin cutting piece found that the processing efficiency of PCD material using brass electrode wire is low.In order to improve the processing efficiency of PCD materials,transition metals containing high reactivity with carbon are used as tool electrodes;in order to avoid the graphitization of EDM PCD,the gas EDM method is used;combining the above two points,a dry type of PCD is proposed.Contact Electrical Discharge Machining(Dry Contact Electrical Discharge Macing,DC-EDM)method.Through the experimental study,the following conclusions are drawn: 1)Under the low discharge energy,the EDM wire electrode can process PCD(diamond average particle size 5μm)continuously and stably in the gas medium.2)Under certain conditions,the processing efficiency of contact discharge machining PCD is higher than that of non-contact discharge machining.The mechanism of improving PCD machining efficiency was analyzed.Finally,the copper-nickel alloy electrode wire containing transition metal is used to process the PCD ultra-thin cutting sheet in the air medium by the contact processing method,and the PCD cutting edge with the edge thickness of less than 50 μm is processed.It shows that the proposed two-wire electrode EDM can realize the machining of PCD ultra-thin cutting edge.In order to further improve the processing efficiency of EDM PCD materials,it is proposed to use high and low voltage composite pulse power supply to process PCD.Use DSP(Digital Signal Processing)+ FPGA(Field Programmable Gate Arrary)to convert and control the high and low voltage composite pulse power supply in the process of processing.Draw the schematic diagram of the power amplifier board and make the PCB board.Finally,it is verified by experiments that high and low voltage pulse power supply can improve the efficiency of EDM PCD.In order to improve the processing efficiency of PCD ultra-thin cutting plate,this paper proposes a processing scheme of double-wire electrode EDM grinding PCD ultra-thin cutting plate,and conducts a preliminary study.It lays the foundation for the efficient,high-precision and high-quality machining of PCD ultra-thin cutting blades.It is of great significance to master the manufacturing technology of high-performance PCD ultra-thin cutting sheets.