The Research Of EDM Pulse Generator For Difficult-To-Cut Materials

Along with the development of Electronics, Space technology and Ocean Engineering, there are many kings of Difficult-to-cut Materials (ex. ceramics, metal matrix composites, polycrystalline diamond, cemented carbide ), witch not only have the characteristic of high hardness, high strength, high wear resistance, but also high melting point, high corrosion resistance. It's difficult to process by both cutting and edm. The dissertation systemic review the edm present situation for machining Difficult-to-cut Materials, especially the influence of pulse power supply.Based on the insight study on mechanism of material removal of edm , this paper analyzes the main factors of the removal rate. As an example, this paper study cemented carbide to develop the relationship between mechanical properties of material and the removal rate by edm.To the instability of discharge, low efficient in edm processing, the paper proposes a new edm power supply with explosion and analyzes the formation of discharge explosion, especially the influence with the removal rate. The heat transfer model of the discharge has been established and the Thermodynamic Finite Element Analysis has been done. At last there is an experiment to verify the analysis.A new kinds of pulse power supply discharged with explosion is designed based on the study of formation reasons of explosion. The pulse generator is composed of low-voltage loop, high-voltage loop and capacitor loop. And a pulse generator has been built by CPLD.According to the contrast experiments, the pulse power supply with explosion is capable of high speed, stable machining.