- Oct 28, 2024
What is wire-cut EDM?
1.1 What is electrical machining?
Electrical machining, also known as Electrical Discharge Machining (EDM), belongs to the technical category of special machining and is an important part of advanced manufacturing technology. It is an important supplement and development of the most widely used mechanical cutting and grinding processes in the machinery manufacturing industry.It mainly includes: Electrical Discharge Forming (EDM), Wire Cut EDM (WEDM), and High-speed Small Hole Machining.
It should be noted that during the EDM process, the brass wire (molybdenum wire, brass electrode tubes) does not contact the workpiece, they maintain a certain distance (called a gap). A certain voltage is applied between the workpiece and the brass wire (molybdenum wire, brass electrode tubes). When the brass wire (molybdenum wire, brass electrode tubes) is fed to the workpiece to a certain distance, the working fluid between the two electrodes is struck. Spark discharge occurs locally, and the instantaneous high temperature generated by the discharge melts or even vaporizes the surface material of the workpiece, gradually eroding the workpiece. By controlling the continuous pulsed spark discharge, the workpiece material can be etched according to people's expected requirements to achieve the purpose of processing, so it is called EDM.
1.2 What is wire-cut EDM?
Wire-cut electric discharge machining is one of the more commonly used special processing methods. In special processing, it also belongs to the category of electric discharge machining. It is a process method that directly uses electric energy and thermal energy for processing. It is not a cutting method like saw blade cutting in people's conventional thinking. The cutting of the saw blade is "hard cutting" in processing, that is, "to overcome rigidity with rigidity", which requires the hardness of the saw blade to be higher than the material being cut, and does not require conductive properties between the two; while wire-cut EDM processing is " "Soft cutting", that is, "softness overcomes hardness", does not require the hardness of the brass wire (molybdenum wire, brass electrode tubes) to be higher than the material being cut, but requires both to be conductive objects.
During wire cutting, the brass wire (molybdenum wire, brass electrode tubes) and the workpiece have relative servo feed motion and vertical linear relative motion in the two horizontal directions of X, Y and U, V at the same time. Because this method uses a moving metal wire (brass wire, molybdenum wire, brass electrode tubes) as a tool electrode to generate spark discharge with the workpiece to cut the workpiece, it is called wire cutting. Since the relative cutting motion of the workpiece and the electrode wire in today's wire EDM machines is controlled by CNC technology, it is called CNC wire-cut EDM.
The basic principle of wire EDM processing is to use brass wire (molybdenum wire, brass electrode tubes) as the tool electrode, apply a pulse voltage of 60~300V between the brass wire (molybdenum wire, brass electrode tubes) and conductive workpieces such as copper, steel or super-hard alloy, and maintaine a gap (5-50μm), which is filled with insulating media such as pure water (electric spark special oil, JR-3A emulsifying ointment, DIC-206 Water soluble wedm concentrate). Spark discharges are consumed and corroded by each other, and countless small pits are electrically etched on the surface of the workpiece. Through the monitoring and control of NC control and the execution of the servo mechanism, this discharge phenomenon is made uniform, so that the workpiece reaches the size required by the product. and shape accuracy.