Recent Developments in Wire Electrical Discharge Machining

Introduction

One of the most widely and commonly used and popular non-traditional material removal procedure which is currently used often to manufacture components with complex shapes having great accuracy and precision is WEDM or better abbreviated as Wire Electrical Discharge Machining. Basically, it is deliberated as an extension of EDM (Electrical Discharge Machining) procedure which utilizes an electrode for starting the sparking process. Though, Wire-EDM uses a wire which acts as an electrode (as in EDM) which is continuously traveling and is generally made up of thin brass, tungsten or copper, and is having a small diameter of 0.05-0.3 mm, and is quite competent of getting small corner radii. Part and the wire are submerged in dielectric (electrically non-conducting) fluid which additionally flushes away debris and acts as a coolant (Kuriakose and Shunmugam, 2004). Wire motion is regulated numerically to accomplish coveted 3-dimensional shape and high precision of work-piece (Mahapatra and Patnaik, 2006). With the help of a mechanical tensioning device, the wire is kept in tension, diminishing chances of creating inaccurate parts. Amid wire electrical discharge machining procedure, the material is eroded before wire and no immediate contact is there between workpiece and the wire, removing mechanical stresses amid machining. Likewise, the WEDM procedure can machine heat treated steels and high strength and temperature resistive (HSTR) materials.

WEDM were firstly used within industrial and manufacturing enterprises in the late 1960s. Advancement of the procedure was a consequence of looking for a system to supplant machined electrode utilized as a part of EDM. In the year 1974, D.H. Dulebohn connected optical line follower system to naturally govern the shape of section chosen to be machined by wire electrical discharge machining procedure (Jameson, 2001). By the year 1975, its acceptance was quickly increasing, as procedure and its capacities were well comprehended by companies and industries (Jameson, 2001). Just before the end of the 1970s, at a time when computer numerical control (CNC) system was brought into wire electrical discharge machining which achieved a noteworthy development of machining procedure. Subsequently, expansive capacities of WEDM procedure were widely used for any through-gap-opening machining inferable from wire, that needs to get through the part to be machined. Basic uses of wire electrical discharge machining incorporate extrusion tools and die, fixtures and gauges, models, airship and medical parts, and fabrication of stamping, grinding wheel form tools. This procedure has been generally utilized as a part of aviation, nuclear and car ventures, to machine exact, irregular and complex shapes in different hard to-machine electrically conductive materials (Jain, 2005; CunShan, 2012; Benedict, 1987). As of late, WEDM practice is additionally being utilized to machine a wide range of micro and miniaturized scale parts in sintered materials, alloys, cemented carbides, metals, ceramic and silicon (Mukherjee et al. 2012). These qualities make wire electrical discharge machining a procedure that has stayed as a competitive and economical machining choice satisfying requiring machining necessities forced by short product development cycles and growing expense [Ho et al., 2004; Jameson, 2001].