Surface Texture Transformation in Micro-Cutting of AA6061-T6 with the Rehbinder Effect

Abstract

The Rehbinder effect (R-effect) on microcutting has been successful to augment machinability of ductile metals; however, there is a lack in understanding of its influence on texture evolution in the machined surfaces. This study validates the R-effect on AA6061-T6 and characterises the influence of the R-effect on the texture transformation in the machined surface. Microhardness tests reveal that the R-effect produces softer surfaces (87–96 HV) as compared with the surfaces produced conventionally (96–108 HV), which is attributed to the differences in grain types. A large fraction of substructured grains (96.4%) exists in the surfactant-affected subsurface while a higher proportion of deformed grains (42.8%) forms during conventional microcutting. In addition, the main texture components of the conventionally produced surface are Cube, Goss and S textures, which differ from the dominant volumes of Copper and R textures under the R-effect. The differences are results of the stress states induced during microcutting, which is exemplified through numerical simulations that consider the reduction in fracture toughness of the material with the R-effect. The advanced understanding of the R-effect better positions the use of surfactants as a cleaner near-dry metalworking fluid.