Surface integrity and microstructure changes in 3D elliptical ultrasonic assisted turning of Ti–6Al–4V: FEM and experimental examination.

Improvement of surface integrity is one of the machining desires where different parameters are related to this phenomenon. Therefore, the effect of 3D elliptical vibration on different aspects of surface integrity is investigated, in this study. Surface roughness, microstructure changes (grain size), and microhardness plus cutting forces and tool-chip friction are experimentally investigated. Moreover, to clarify more details, finite element simulation of microstructure changes is carried out when conventional and 3D elliptical ultrasonic assisted turning of Ti–6Al–4V alloy are implemented. As a result, it was revealed that 3D vibration method causes the smaller grain size to be generated compared to conventional process. In addition, this method could improve the isotropy of the surface by generation of semi-spherical micro-textures. Image 1 • Experimental and 3D finite element simulation of microstructure changes are carried out. • A 3D ultrasonic assisted turning tool is used to evaluate of surface integrity of Ti–6Al–4V. • 3D vibrations could reduce the grain size improving the surface microhardness. • Semi-spherical micro-textures were generated by using 3D vibrations improving surface isotropy. [ABSTRACT FROM AUTHOR]