Study On Parameter Optimization And Discharge Distribution For WEDM Of Variable Thickness Workpiece In Ultrasonic Water Mist

With the continuous progress of modern industrial machining technology,especially in the field of special machining,it must be mentioned that WEDM can process any metal or non-metallic materials with hardness,strength,toughness and brittleness,and is good at machining complex,micro fine surfaces and low stiffness parts.In actual processing,it is usually processed in working environments such as emulsified media,atmospheric media,and water mist media.Compared with other media,gas WEDM technology has the advantages of small machining surface roughness value,high linear accuracy,narrow discharge gap and no electrochemical corrosion on the machining surface.It is often used in precision machining,but in on-line cutting,The distribution of WEDM discharge points will affect the surface machining quality of the workpiece,so this paper studies the uniformity of the distribution of discharge points in WEDM to judge the surface machining quality of the workpiece.Depending on the characteristics of the different discharge dot testing methods,this paper uses the potential difference method to study the position distribution of discharge points.At the same time,analyze and process depending to abnormal points of electrical signals,it ensures the accuracy and reliability of the calibration function,and lays a data foundation for the study of spark discharge point position detection and uniformity evaluation.In terms of discharge point position detection and discharge point uniformity evaluation system,this paper uses LabVIEW software to design the detection and evaluation system program more reasonably.The system is more concise and practical,preventing systematic errors in multi-process detection,further improving the detection accuracy of the detection system,and realizing the accuracy of discharge point location distribution detection and discharge point distribution uniformity evaluation.This paper also adds electrical signal data acquisition program module,analog-to-digital signal conversion program module,cutting parameters determination module,abnormal signal filtering program module,system memorandum program module,more perfect detection system function,more in line with the current detection requirements.In the experimental part,firstly,three cutting experiments were performed on workpieces with variable thickness of 20 mm,40mm,60 mm and 80 mm in emulsion,steam aqueous mist and ultrasonic aqueous mist by using a wire EDM machine.The wire cutting experiment was completed in the order of processing,and then the single factor experiment was used to analyze the influence of electrical parameters and non-electrical parameters on the surface roughness,uniformity,cutting speed and erosion depth of the workpiece.Finally,Minitab software was used to design orthogonal experiments combined with signal-to-noise ratio analysis and Grey correlation-satisfaction function analysis to optimizes parameters.By comparing the two optimal schemes,the optimal parameter combination data is selected to meet the requirements of finishing experiment and achieve the surface consistency of thickening workpiece machining.