On the Use of 17-4 Precipitate Hardened Stainless Steel Waste Powder for 3D Printing of Implants with Tuneable Stress Shielding Capabilities

In the past decade, several studies have reported the 3D printing of 17-4 precipitate-hardened (PH) stainless steel (SS)-based functional implants using the direct metal laser sintering (DMLS) process. But hitherto, little has been reported on using DMLS waste powder for implant fabrication with stress-shielding capabilities. This study highlights the effect of infill patterns (Solid, Octet, Weaire-Phelan (WP) embedded as meta-structures) on the mechanical, morphological, corrosion, and wear properties for minimizing the stress shielding effect on 3D printed implants of 17-4 PH SS. The results suggest that the Octet meta-structure is better infill as compared to solid and WP with improved ultimate tensile strength (37.68%, 6%), strain (13.05%, 4.65%), surface hardness (27.80%, 26.87%), and surface roughness (Ra) (9.97%, 23.70%) for enhanced stress shielding capabilities. From a specific wear rate and corrosion rate (CR) viewpoint, WP is better than solid (114%, 77.92%) and Octet (123%, 85.71%) meta structures, respectively. The results are supported by scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) analysis.