Study On The 3D Micro-EDM Milling Strategy Based On Fix-length Compensation Method Using Tube Electrode

Fixed-length compensation method is an efficient compensation method in micro EDM machining.The method can be applied for cavity milling with big layer thickness.A Cone shape end forms while using solid electrode during fixed-length milling.The shape has difficulties in plane milling and it make the machining strategy become more complicated.Fixed-lenght compensation based on tube electrode is proposed to improve the accuracy of cavity milling.Mathematical model is established for fixed-length compensation method with tube electrode and the relationship between compensation length and machined depth is set up as well as machined angles.A simulation model is set up based on Maxwell's theory to physically simulate the discharge machining process.The simulation model is applied forfixed-length milling with tube electrode to verify the shape forming process and machining stability of the truncated cone shape electrode end.Besides the influences of compensation length on machining results are studiedShape forming process and stability of the truncated cone shape end is verified by single groove milling experiment as well as the impact of compensation length on machined depth and angles.The method for single groove milling is proposed and samples are machined with different paths.The results fit the theoretical and simulation results well,providing theoretical foundation for further researches.Plane milling method and mathematical model is developed based on overlap rate and the validity of the method is verified by double grooves milling experiments.The method is applied to 3D cavity milling and strategies for both single layer and layer containing closed pattern are concluded.Different samples are machined and the machining accuracy is controlled within 3?m.