WEDM as a Replacement for Grinding in Machining Ceramic Al2O3-TiC Cutting Inserts

Small-size cutting inserts for assembly cutters are widely used to manufacture a variety of parts the aerospace, automotive and mechanical engineering industries. Due their high hardness chemical stability, Al2O3-TiC ceramics significantly outperform hard alloys in machining heat-resistant difficult-to-machine materials. However, grinding on CNC machines, most common technology manufacturing ceramic inserts, is associated with numerous issues when it comes small-size inserts. For example, forces wheel wear rates cause rapid loss dimensional accuracy deterioration quality surface being machined, while interference treated imposes serious limitations geometry be grinded. Here we show that Wire Electrical Discharge Machining (WEDM), which contactless and, thus, more flexible method terms size geometrical properties workpiece can as replacement operations small A composite 70% aluminum oxide 30% titanium carbide was chosen material because further increase TiC fraction causes marked decrease resistance, its results an undesirable electrical conductivity. While order replace WEDM, WEDM has stable sense occurring without frequent wire breakages, achieving stability not easy task due low conductivity operational temperatures, promote diffusion dielectric electrode products layer machined. These factors may lower final product damage insert surface, increases roughness RA layer, friction coefficient hence, reduces life manufactured We have increased process by identifying applying rational conditions lead reduced, factor 2.63, Ra also 1.3, depth craters. Performing structural analysis, found application energies combined increasing interelectrode gap (IG) (technological parameter SSol, complex indicator determines speed depending number pulses per unit time IG size, set at 80, EDM3 technology) contamination, (SSol = 45, EDM1 removal rate contamination working zone between machined electrodes. After reducing lowering SSol from 80 0.344 µm achieved, allows replacing hardening chamfers, front surfaces lesser degree, rear support In this case, reduced electroerosion local breakdowns, turn produce large deep craters adversely affect performance slight 45 55 (EDM3 lowers 50 ?m 37 ?m. Although case grows 0.534 discharge energy, improved flushing occurrence high-temperature breakdowns—evidenced formed current localization during short circuits—significantly crater formation rate. Therefore, recommended use reinforcing chamfers surfaces. considerations us conclude viable alternative shape, poorly conductive should studied further.