Analysis And Experiment Of Tool Electrodes And Parameters Of Arc Plasma In Deep Hole Machining

In the traditional drilling process,there are problems such as tool wear and even tool edge collapse,which seriously affect the machining efficiency and tool life.In addition,some special metal materials are restricted by process conditions,which increases hardness and processing charges.Therefore,a more appropriate processing method is urgently required to settling these problems.Arc plasma processing technology is not limited by the physical properties of the processed materials,and there is no cutting force on the processed workpiece.It possesses the advantages of high effect,sanitize and no pollution.It is a special processing method.Presently,the study on this technology is still in the start stage,and the application of arc plasma machining technology to deep hole machining provides a new process approach for deep hole machining.This paper mainly takes deep hole machining and special machining as the background,finite element simulation and machining test as the main means,combined with the specific deep hole machining project,the arc plasma machining technology is studied.Firstly,the processing principle and process of arc plasma are analyzed in detail.It is pointed out that the arc plasma processing is essentially a short and complex energy conversion process,and the factors affecting the arc plasma processing are clarified.According to the processing principle and test conditions,the corresponding arc plasma deep hole machining system is designed,which is one of the innovations of this paper.The system mainly includes four parts: external power supply,tool electrode,cooling system,machine tool body and tooling structure,which provides conditions for completing the test of this topic.Based on FLUENT fluid software,the flow filed simulation geometric model of machining clearance is set up.By changing the geometric model,coolant pressure and tool electrode rotational speed,the variation regulation of flow velocity and pressure of machining clearance is analyzed.By setting different values of coolant pressure and tool electrode speed,the qualitative relationship between the midpoint velocity of the flow field in the end face machining gap and the coolant pressure and tool electrode speed is obtained.The tool electrode structure designed in this link is another innovation of this paper.The arc plasma machining experiments of alloy steel and beryllium bronze were made by adopting the single factor experimental way.The influence of machining parameters such as feed rate,electrode speed and coolant pressure on the average short circuit number was analyzed,and the correctness of the flow field model of machining gap was verified.Through the analysis of tool electrode length loss and relative loss,the influence of processing parameters such as feed rate,peak current and electrode speed on tool electrode loss is obtained.By comparing the processing conditions of the two workpieces,the results show that under the same processing conditions,the processing stability of beryllium bronze is lower than that of alloy steel,and the processing performance of tool electrode for beryllium bronze is higher than that of alloy steel.