Research On The Electrode Wear Based On Energy Detection In Micro-edm Deep Small Hole

The micro-deep hole manufacturing technology of difficult-to-machine materials seriously restricts the development of the aerospace equipment in China,which is typically represented by the Film Cooling Holes of Aeroengine Blades.That the micro-EDM technology has advantages of high manufacturing precision,no residual stress and no limitation on mechanical properties of materials makes it has unique advantages in the processing of micro-deep holes for difficult-to-machine materials.The micro-electrode is an important factor that affects the manufacturing precision of the micro-EDM deep-small hole,and the effective energy of the discharge gap directly determines the amount of micro-electrode wear.Therefore,the study on the effective energy of the discharge gap and micro-electrode wear in microdeep hole machining is of great significance for improving the precision of microdeep holes and providing an experimental basis for the processing industry.In order to better realize the micro-deep hole machining of titanium alloy,and to meet the performance indexes,such as low electrode wear,high processing efficiency,the aspect ratio requirement and good machining quality,it is necessary to study the combination scheme of the parameters of micro-deep hole drilling.Firstly,based on the single factor experiments,the relationship between processing parameters of three kinds of micro-energy pulse power modes,including RC,TC and TR power supply,and the performance indexs was studied.It was found that the TR power supply has smaller discharge gap,lower electrode wear and better orifice machining quality when the processing efficiency is similar.Then,the TR power supply was selected as the power supply of the experiment and the related processing parameters were determined,which included its machinable range.Based on the orthogonal experimental method,the optimization of processing parameters was carried out,and the influence of various processing parameters on multiple performance indexes was comprehensively balanced.In the end,based on Titanium alloy workpiece,the optimal combination scheme of the processing parameters of micro-deep hole drilling was determined.In order to realize the accurate calculation of the effective energy of the discharge gap in micro-EDM,it is necessary to build an effective energy detection system of the discharge gap.Firstly,a high-speed acquisition system for the electrical signals of the discharge gap was established.The LabVIEW was used as the development environment for the data acquisition program to realize high-speed synchronous acquisition of the electrical signals.Through the energy detection module,efficient discharge state identification and accurate calculation of the power and effective energy of the discharge gap were both realized.Then,a comparison experiment between the calculated value of the energy detection system and the actual value was carried out to verify the accuracy of the energy detection system.After the processing parameters selection and the energy detection system had been accomplished,the micro-deep hole processing experiment based on energy detection was launched.The processing experiment was divided into three stages in sequence.The name of the first stage is the large feed depth and the blind hole segmentation processing stage that occurred before the electrode wear becomes stable.Through-hole continuous processing stage and the small feed depth and the blind hole segmentation processing stage occur when the electrode wear is stable.The microelectrode wear and the effective energy of the discharge gap were studied.It was found that the amount of micro-electrode wear is parabolically related to the effective energy of the discharge gap when the electrode wear is not a stable elliptical arc.When the electrode wear is stable,there is a linear relationship between them both in through-hole continuous processing stage and the small feed depth and the blind hole segmentation processing stage.Through the temperature field simulation of microelectrode wear,the reason for the stable state of the micro-electrode wear was explained according to the change rule of the size of the pits discharge of single spark at different positions at the electrode end.