Effect of Vegetable Oil–Based Hybrid Nano-Cutting Fluids on Surface Integrity of Titanium Alloy in Machining Process

Abstract

Abstract In the present work, an attempt is made to examine the machining performance in turning titanium alloy using vegetable oil–based hybrid nano-cutting fluids. The sesame oil–based hybrid nanofluids with carbon nanotubes (CNT)/molybdenum disulphide (MoS2) in the ratio of 1:2 are used to test the effect of surface integrity in the machining of titanium alloy. The cutting forces, cutting temperatures, surface roughness, and microhardness of the machined surface were measured. The machined surface is analyzed for machining-induced residual stresses and changes in the surface topography. Machining performance improved with vegetable oil–based hybrid nano-cutting fluids in reducing cutting forces and cutting temperatures. The percentage reduction of temperatures in the cutting zone under 0.5, 1, 1.5, and 2 wt. % and conventional cutting fluids (CCFs) are 70.2, 58.2, 63.1, 67.3, and 56.7, respectively, compared with dry machining. The percentage reduction in cutting forces are found to be 39.4, 70.9, 42.7, 73.2, and 72.3 for CCF 0.5, 1, 1.5, and 2 wt. % nanoparticle inclusions (NPI) compared with dry cutting, respectively. The percentage reduction in surface roughness (Ra) under CCF is 9.6, 24.4, 23.2, 22.4, and 26.7 for 0.5, 1, 1.5, and 2 wt. % NPI respectively, compared with dry cutting. The microhardness of the machined surface increased, and residual stresses are encouraging with hybrid nano-cutting fluids.