Assessment of textured broach lubricated with carbon fiber and calcium sulfonate composite grease

Abstract

Due to the heavy load of broaching, a severe shearing effect occurs between the tool material and workpiece material, resulting in tool wear and a decrease in the quality of the workpiece. The groove is introduced into the flank surface of the tool to improve its tribological properties. Moreover, a mixed lubricant (G/CF) containing carbon fiber (CF) and calcium sulfonate composite grease (CSG) is used in the textured tool. The lubricating properties of G/CF are then investigated by broaching steel 1045 (AISI). Cutting force, the surface morphology of the workpiece and tool, and cutting vibration are used to evaluate the cutting performance of the tool under different lubrication conditions. The results show that G/CF reduces the cutting force by 12 % and the surface roughness of the workpiece by 36.7 % compared with dry cutting. The reason is that the carbon fibers attached with grease are taken out of the textures during cutting to re-lubricate the friction pair. In addition, carbon fibers adhering to the workpiece surface prevent debris from damaging the machined surface. Therefore, adding G/CF to the groove improves the cutting performance of the tool and provides a useful reference for the research of self-lubricating tools.