SUMMARY

In machining processes, higher friction and wear can result in more frequent tool replacement, higher energy consumption, lower dimensional accuracy, and inferior surface quality. Therefore, methods to modify cutting tool surfaces to improve their tribological performance, thus leading to more sustainable and efficient machining, are of great importance to the manufacturing industry and to the research community. Here, a mechano-chemical surface modification is proposed to improve cutting tools’ performance. The approach consists of modifying the rake faces of cutting tools through localized plastic deformation of the near-surface region accompanied by a simultaneous exposure to a proper chemical precursor. Shot peening with a mixture of Al2O3 and Cu2S particles, with the former serving as the mechanical agent that enhances the chemical reactivity of the surface through plastic deformation and the latter serving as a chemical precursor, will be utilized to form a lubricious layer on the cutting tool surfaces. The potential and capability of the shot-peening-based mechano-chemical surface modification of cutting tools will be explored in the following way. 1) WC inserts will be mechano-chemically modified to examine cutting forces and tool wear with respect to the chemical composition, roughness and residual stresses of the tested tool surfaces. 2) The effect of mechano-chemical surface modification of high-speed steel (HSS) cutting tools on the reduction of cutting forces will be investigated and supplemented with the analysis of surface chemistry and topography. 3) The effects of critical surface modification parameters on the surface chemistry, topography, hardness and residual stresses will be studied and correlated to the machining performance of HSS cutting tools. 4) Finally, the wear resistance of mechano-chemically modified HSS tools will be examined along with the corresponding changes in the surface properties.