Gap Flow And Machining Process Research Of Small Hole Drilling By Edm Using Dielectric With Disperasant

After several years, EDM has developed to a kind of widely used and mature special processing. EDM own some advantages which other processing methods do not have.EDM can machining hard cutting materials and complex shape parts ,while General machining approach cuts them hard ;machining without cutting force; does not lead to defects such as burrs and knife marks grooves; tool electrode material need not harder than the material of workpiece ,use of energy processing directly ,easy to achieve automation etc .However, there are some problems exist in the small hole drilling by EDM when the depth-to-hole diameter ratios is comparatively large, Corrosion products generated during the processing remaining in a narrow gap is difficult to expel timely. As a result, processing becomes instability and it is difficult to improve the speed of processing efficiency. In order to improve the condition of expelling debris, Finishing Technology Institute of Taiyuan University of Technology raise a EDM approach using dielectric with dispersant .This paper analyzes the mechanism of small hole drilling by EDM using dielectric with dispersant , and carried out in-depth studies combined experimental and simulation.1)It analyses the factor that impact the efficiency of EDM, analysis effect on the process of expelling debris by Colloidal systems and the suspension formed in the EDM proceeding. That work made a well foundation for mechanism of small hole drilling by EDM with dispersant working fluid.2)This paper analysis the mechanism of EDM with dispersant working fluid and the influence to distributed system (formed by Corrosion product and dielectric fluid) and why the conditions of expelling debris improved after adding dispersant to the dielectric fluid.3)After adding dispersant to the dielectric fluid, this paper analysis the effect on material removal rate and relative wear of electrode by combinations of dispersant working fluid and this theory is verified by experiments. It analysis the relationship between combinations of dispersant working fluid and material removing rate,relative electrode wear in determining the electrical parameters, etc.4)This paper establishes geometric model of the expelling debris process by Gambit and analysis the influence of concentration of dispersant and dispersion to gap flow field through Fluent simulating both the process of EDM using water working fluid and the process using dispersant working fluid respectively .All of these jobs provide guidance for the application of EDM small hole machining with dispersant working fluid from the perspective of modeling and simulation.