Hybrid high speed machining (HSM): System design and experimental results for grinding/HSM and EDM/HSM

Point grinding and electrical discharge machining (EDM) are detailed on hig h speed machining centres. A Taguchi design was employed to evaluate operat ing parameters when point grinding (plunge) nickel-based superalloys with 1 5 mm diameter electroplated diamond and cubic boron nitride (CBN) wheels us ing speeds up to 60,000 rpm provided by an ancillary spindle. Material remo val of up to 120 cm(3) and roughness values down to 1.2 mum Ra were obtaine d when machining Inconel 718. A retrofit EDM servo head unit was designed f or die sinking and workpiece surface texturing. When texturing 2D and 3D wo rkpieces, surfaces were produced with an Ra of 1-10 mum, depending on opera ting parameters.