▎ 摘　　要

The heat generated during the machining of titanium alloys accumulates in the cutting area during machining. These high temperatures lead to tool wear, affect the quality of the machined surface, and alter the cutting force. In light of this, a new method for mixing vegetable oil additives is proposed herein, through the addition of graphene nanoparticles and sulfur-based extreme pressure (EP) additives to canola oil to improve the lubrication and cooling performance of the machining area. The optimum results were found for the combination of canola oil + graphene + sulfur-based EP additives, which effectively decreased the temperature of the cutting area and wear of cutting tools. In comparison to canola oil, the flank wear value decreased by 56.4%. Similarly, the surface roughness and cutting force when using the canola oil + graphene + sulfur-based EP additive were the lowest, exhibiting a decrease of 36.1% and 27.0%, respectively, in comparison to simple canola oil. The inorganic film produced by the EP additive molecule helps prevent direct contact between the tool and the workpiece, reducing tool wear and improving surface quality. Furthermore, adhered chips were also observed, with a layered morphology. Graphene shortens the length of the chip-adhesion layer (0.081 mm) and reduces adhesion wear. Elemental testing confirmed that graphene penetrates more easily into the manufacturing area, which is beneficial to reducing abrasive wear and the cutting force. In addition, the higher thermal conductivity of graphene will effectively reduce the temperature of the cutting area, which impedes the agglomeration of these chips. This weakens the adhesion of the chips to the surface of the workpiece.