Research On Machining Precision Micro Structures Using Micro-EDM

Micro-EDM adopts the non-contact discharged method to remove materials,its surface is not affected by macro force.Especially for the machining of difficult-to-cut materials,the materials always possess excellence properties with high strength and hardness,it can be considered as one of the most promising manufacturing process.In the field of micro-EDM machining,microholes of large depth and grooves are still a difficult point.The low discharged energy lead to a smaller discharged gap,which is always in a few microns.So it is difficult to remove the debris out of deep hole,which result in unstable machining process and high tool wear,large taper angle.In order to analysis the main influence factor of micro-EDM machining in machining efficiency and electrode wear ratio,the paper take orthogonal experiments respectively on the discharge parameters of the voltage,current,pulse width,frequency.Discharged frequency plays a major role for the material removal rate,and the main effect of electrode wear ratio is voltage.According to the auxiliary process parameters,such as the time interval,the height of the lift and the rotational speed of the electrode were tested respectively,all of them had a significant effect on improving the processing efficiency.Meantime,the experiment of AlSiC and 06Cr19Ni10 showed the thermal properties were important for the surface of work,it was found that the lower melting point got the rougher machined surface and the higher thermal conductivity formed the smoother micropore edge.Secondly,a simulation model was made for the micro hole with the electrode rotating and shaking,and experiments were done by machining the depth holes.It shows that there exists transverse and longitudinal velocity gradients at the bottom of the rotating electrode,which promotes chip moving upward,and chip removal benefits from the non symmetric flow field in the electrode shaking processing.Finally,microholes and grooves processing on micro EDM were analyzed,both of the cutting edge electrode and electrode shaking with reasonable layers can effectively reduce the microholes' taper;the residual error of side and bottom of micro groove can be reduced effectively by adopting fixed length compensation method and planning electrode path.