Experimental study on micro electrical discharge machining of porous stainless steel

Various cutter strategies have been developed during milling freeform surface. Proper selection of the cutter path orientation is extremely important in ensuring high productivity rate, meeting the better quality level, and longer tool life. In this work, finish milling of TC17 alloy has been done using carbide ball nose end mill on an incline workpiece angle of 30°. The influence of cutter path orientation was examined, and the cutting forces, tool life, tool wear, and surface integrity were evaluated. The results indicate that horizontal downward orientation produced the highest cutting forces. Vertical downward orientation provided the best tool life with cut lengths 90–380 % longer than for all other orientations. Flank wear and adhesion wear were the primary wear form and wear mechanisms, respectively. The best surface finish was achieved using an upward orientation, in particular, the vertical upward orientation. Compressive residual stresses were detected on all the machined surfaces, and vertical upward orientation provided the minimum surface compressive residual stress. In the aspect of tool wear reduction and improvement of surface integrity, horizontal upward cutter path orientation was a suitable choice, which provided a tool life of 270 m, surface roughness (R _a ) of 1.46 μm, and surface compressive residual stress of ?300 MPa.