Study On The HS-WEDM For TC4 Titanium Alloy Workpiece Attaching To Ultrasonic Vibration

Wire electrical discharge machining(WEDM)is a kind of special machining method which uses the energy generated by intermittent pulse discharge between the wire and the workpiece to remove the conductive material.It has been widely used in the aerospace,electronics,civilian and other industrial areas,because it can process with a variety of complex structures,special requirements of the workpieces and difficult-to-machine materials.But with the continuous progress of science and technology,the machining requirements of WEDM are also getting higher and higher.The combination of ultrasonic machining and WEDM can effectively improve the machining efficiency and surface quality which has been concerned by many experts and scholars at home and abroad.The ultrasonic vibration device is loaded on the wire electrode in the current study,but there are many shortcomings,for example,it will affect the machining accuracy of wire electrode in the machining and the ultrasonic vibration device is difficult to loaded on the electrode wire in the taper machining and so on.In this paper,we study the effect of ultrasonic vibration device on the workpiece.In this paper,firstly,the feasibility of workpiece ultrasonic HS-WEDM is analyzed by analogy method,then the ultrasonic vibration device is designed,mainly for the workpiece and fixture design,and the well designed ultrasonic vibration device is installed in the DK-7720 Z HS-WEDM machine for debugging and calibration.Secondly,the experimental research of TC4 titanium alloy is carried out by conventional HS-WEDM.The influence of electric parameters on the surface roughness and cutting speed,and the optimal parameters of the above two technical indicators are analyzed.Main electric parameters are current,pulse width and pulse interval.Thirdly,TC4 titanium alloy is processed by workpiece ultrasonic HS-WEDM.The experimental data are analyzed by range analysis,variance analysis and signal to noise ratio analysis.Then,the influence of the different cutting direction of the electrode wire on the surface roughness and cutting speed are studied under the same process conditions by the contrast test method,and the effects of ultrasonic and no ultrasonic on the above two process indicators are studied under the same process conditions by using the comparative test method,the results indicate that the addition of ultrasonic vibration on the workpiece,the surface roughness decreases obviously,ultrasonic vibration along the cutting direction can obtain the best surface roughness,and the cutting speed can only be improved obviously under some electrical parameters.Fourthly,the improvement of the working condition is analyzed in four aspects when the ultrasonic vibration is applied in HS-WEDM.Then in the workpiece ultrasonic HS-WEDM process to maintain the electrical parameters unchanged to change the ultrasonic frequency and ultrasonic amplitude,it is found that there exists an optimum relationship between the machining power and the machining time by which we have the best of both worlds,the cutting speed and the surface roughness.Finally,based on the BP neural network,the forecasting model of the workpiece ultrasonic HS-WEDM machining is established.By comparing the simulation value with the actual value,it is proved that the forecasting model has strong ability of learning and generalization.