Dry electropolishing of Ti6Al4V samples produced by laser powder bed fusion for bone

Department of Mechanical and Mechatronics Engineering, Central University of Technology, Bloemfontein, South Africa

Abstract

This study describes the DLyte dry electropolishing of heat- treated Ti6Al4V samples (vertical, horizontal and semi-sphere samples) produced by laser powder bed fusion technology. The Ti6Al4V samples were divided and build-in zones according to the Argon inlet and outlet as well as the start and end areas of the powder distribution within the building plate. The as-build Ti6Al4V samples were investigated for their suitability in medical bone implant applications and were found to have a surface roughness that exceeds the standards of a bone implant irrespective of the zone in which they are built. This necessitates additional post surface finishing procedures to achieve the desired surface finish for bone implants. DLyte dry electropolishing was employed for surface finishing to enhance the surface condition of Ti6Al4V as-build samples. The Ti6Al4V as-build samples were polished according to their zones in which they were build. The efficacy of polishing was assessed based on different time intervals (30, 60 and 120 minutes) and the decrease in surface roughness. The results show that after 30 minutes of polishing there was a lower reduction in surface roughness and the higher surface reduction was observed after 120 minutes of polishing. It was noted that as the polishing time increased, the surface become progressively smoother.