Di-Spark Ltd – 3rd part of our guide to EDM – Wire EDM and EDM Hole Cutting
Enquire here for AS9100(c) & SC21 Wire Erosion Machining
4.2 WIRE EDM
Wire erosion machines use a continuously moving wire as the cutting tool. Much like a band saw in principle, the wire (saw blade) feeds from a spool and passes completely through the work-piece. Although this analogy does not do justice to the accuracy and finishes attainable by wire EDM machining, this comparison does enable a layman to envisage the concept of wire erosion. The wire is electrically charged and cuts through the work-piece by spark erosion vaporising and melting the material instead of cutting mechanically like the band saw. Since the wire never physically touches the work-piece, there are no mechanical stresses produced to influence the part or the set-up. Furthermore, wire electrical discharge machining process produces burr-free machining and provided that the work-piece is electrically conductive its mechanical properties (hardness, toughness, brittleness, and ductility) impose no limitations on the machining process.
4.3 EDM HOLE DRILLING
EDM hole drilling machines use round tubular electrodes held in a rotating chuck to spark erode holes. The size range that commercial machines can produce is typically 0.3mm diameter to 3.0mm diameter holes. Special purpose electrical discharge machining hole drilling machines are available that use non-rotating electrodes and can spark several holes at a time. They are typically used in the aerospace industry for producing cooling holes in turbine blades.