INVESTIGATION ON SURFACE INTEGRITY OF SS316L 3D PRINTED STENT

Abstract

This investigation focuses on the analysis of the surface integrity of aStainless Steel 316L (SS316L) powder stent manufactured using Selective Laser Melting (SLM) technology. In the present work different post-processingmethods viz. stress-relieved, electropolished, stress- relieved and electropolished, and without stress-relieved and without electropolished were studied in correlation with the SLM process in the context of stent surface characterization. The process performances were evaluated in terms of surface roughness which is correlated with characterization techniques such as Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction (EBSD).It was observed that electropolished and stress-relieved stent exhibits lower average surface roughness R_a (0.484 μm), root mean square of the profile R_q (0.560 μm), total height of the roughness profile R_t (2.789 μm) and ten-point mean roughness of R_z (1.98 μm), as compared to remaining samples. The average grain size is observed to be 40 μm for the electropolished stress-relieved stent. The obtained results were corroborated by the surface topography, local misorientation angle, grain size, and grain orientation.The overall study exhibits that electropolished and stress-relieved stent surfacewas found to be suitable.