Creep feed grinding of a gamma titanium aluminide intermetallic alloy using SiC abrasives

Experimental results are detailed when creep feed grinding (CFG) a gamma titanium aluminide intermetallic alloy (γ-TiAl) Ti–45Al–8Nb–0.2C with SiC abrasives. When using low porosity wheels at a low wheel speed of 15 m/s and a material removal rate of 62.5 mm/s, G-ratios of ∼15 were produced with workpiece surfaces free of burn. At higher wheel speeds ≥25 m/s, cracks up to 1 mm deep were evident with extreme workpiece surface burn. By increasing the wheel porosity, specific power, cutting forces, workpiece surface burn and cracking were all reduced however, G-ratio was also reduced to ∼4 with heavy profile wear. Operation at 15 m/s with increasing feed rate and depth of cut reduced G-ratio still further to <1, whilst increasing power and forces by up to 250 and 300%, respectively. Surface integrity evaluation showed that it was possible to produce crack free surfaces with defects <10 μm from the workpiece surface at low depths of cut, irrespective of feed rate.