Effects of Glass Bead-Blasting and Vibratory Polishing on Surface Features of Additively Manufactured Ti۶Al۴V-ELI

Selective laser melting (SLM) as an additive manufacturing method has attracted increasing attention because of its ability to produce titanium-based parts for differentparticular applications such as patient-specific medical implants. However, usually post-processing surface treatments are required to decrease the surface roughness ofthe printed implants. In this paper, the influence of two surface treatments including bead-blasting (using siliconbased spherical glass beads) and vibratory polishing wasinvestigated on the surface features of SLMed Ti۶Al۴V-ELI parts. The results of the arithmetical mean roughness (Ra) exhibited that bead-blasting and vibratory polishingdecrease the average surface roughness by ۷۸% and ۱۹%,respectively, compared to that of the as-built specimen(Ra=۶.۹µm). The surface morphology revealed that whilevibratory polishing only eliminates the peaks, bead-blasting removes all the partially melted particles and decreases both peaks and troughs, more efficiently. Furthermore, the combination of these treatments led to the least roughness (Ra=۱.۳µm). When the specimen was bead-blasted followed by vibratory polishing, similar roughness parameters were observed in the surfaces with different orientations. Moreover, the chemical analysis of the treated surfaces illustrated a trace of the blasting and polishing media. Although the blasting was more effective in roughness reduction, it left more residual elements on the surface.

Keywords:

Selective Laser Melting , Ti۶Al۴V ELI , Surface Roughness , Bead Blasting , Vibratory Polishing