Grinding of Ti-6Al-4V Under Small Quantity Cooling Lubrication Environment Using Alumina and MWCNT Nanofluids

Ti-6Al-4V is a difficult-to-grind material as chips tend to adhere to the grit materials of an abrasive wheel due to its chemical affinity. In the present work, it has been attempted to improve the grindability by application of small quantity cooling lubrication (SQCL) technology using nanofluids, namely, multiwalled carbon nanotube (MWCNT) and alumina nanofluid. The suitability of nanofluids was experimentally evaluated in reciprocating surface grinding using a vitrified SiC wheel. Substantial improvement in grindability under the influence of MWCNT nanofluid (SQCL) could be achieved compared to soluble oil (flood). Reduction of specific grinding forces and specific energy was observed due to the combined effect of superior heat dissipation and lubrication abilities; when the latter one was realized through on-site rolling of MWCNT strands, inter-tubular slip and solid lubrication of the film adhered onto the wheel surface. These outperforming characteristics of MWCNT nanofluid helped in retaining grit sharpness superiorly, thus resulting in better surface finish and less re-deposition of metal on the ground workpiece. On the contrary, Al2O3 nanofluid (SQCL) underperformed even soluble oil (flood). For an ageing effect, Al2O3 nanoparticles resulted in abrasive agglomerates, which led to its failure, despite its good heat dissipation capability.