LAUSR

Abstract A recent trend in the processing of difficult-to-machine materials is the replacement of traditional coolants with vegetable oil, which is environmentally friendly. In this study, a new type of blended coolant that is suitable for minimum quantity lubrication (MQL) was developed by leveraging the mutual solubility of castor oil and ethanol. The physicochemical properties of the blended coolant and its effects on cutting vibration, surface hardness, surface roughness and tool wear mechanism under different working conditions were studied. Turning experiments on AISI 304 steel under dry cutting, flood cutting, vegetable oil (castor oil) minimum quantity lubrication (VMQL), 95 % ethanol MQL (EMQL), and blended coolant MQL (BMQL) conditions were conducted using a coated carbide tool. Among all the cooling methods tested, the minimum vibration in the axial and radial axis directions occurred in the BMQL, with vibration intensity reductions of 2.46 % and 3.38 %, respectively. Furthermore, the tool wear and changes in the matrix material surface hardness were the smallest under the BMQL, and the surface roughness decreased by 4.50 % or more. The average wear, VB, of the flank face decreased by more than 7.72 %. The blended coolant proved to be more conducive to cooling for cutting processes under MQL.