Turning Performance of Bonded Cutting Tools with Nanographene or Multi-walled Carbon Nanotube Particle-Reinforced Epoxy-Based Nanocomposite Adhesives

Abstract

In machining operations, mechanically clamped, brazed and bonded cutting tools are utilized. The bonded cutting tools have some advantages over the others especially in precision processes. But, there is not much application due to their low joint strength. Therefore, in this study, turning performance of bonded cutting tools was investigated. Nanographene particle-reinforced epoxy or multi-walled carbon nanotube (MWCNT) particle-reinforced epoxy-based nanocomposite adhesives were produced to enhance the adhesive shear strength and joint tensile strength of epoxy adhesive. Steel-cemented carbide (WC, tungsten carbide)-steel single lap joints were produced by applying these nanocomposite adhesives and neat epoxy-based adhesive to specify the optimum amount of nanoparticle reinforcement. Then, machining operations were performed with inserts attached to the tool holder with mechanical clamping method, neat epoxy adhesive and epoxy-based nanocomposite adhesives by utilizing a CNC lathe. The cutting forces, cutting temperatures and surface roughnesses were measured, and the results were compared by each other. Depending on the experimental results, lower cutting forces and surface roughnesses occurred when using bonded cutting tools than that obtained when using mechanical clamping due to damping properties of the adhesive layer. However, the cutting temperatures measured on the bonded cutting tools were higher than that measured on the mechanical clamped cutting tools because of the low thermal conductivity of the adhesive layer. In addition, it was observed that the nanoparticle-reinforced epoxy-based nanocomposite adhesives increased the cutting forces and surface roughnesses a little in comparison with the neat epoxy adhesive due to increasing the viscosity of the neat epoxy and decreasing the damping properties and also decreased the cutting temperatures due to having high thermal conductivity of nanoparticles. When compared the nanoparticles, nanographene adsorbing better on the adherend surface and providing more homogeneous distribution in the matrix gave better results than MWCNT particles.