On the Use of Recycled Blended Metallic Powder in the Direct Metal Laser Sintering

In the recent past several studies have been reported on the recycling of unused/waste powder of direct metal laser sintering (DMLS) process. But hitherto little has been reported on recycled blended/mixed metallic powder collected as waste from DMLS for various engineering applications. This study highlights the use of recycled blended/mixed powder of 17–4 precipitate hardened (PH) -stainless steel (SS) and Ti–6Al–4V collected as process waste from the DMLS setup. The collected waste powder was mixed in a ball mill, followed by its characterization based on scanning electron microscopy, energy dispersive spectroscopy, and differential scanning calorimetry. Finally, the prototypes with collected waste blended powder were printed at a scanning speed of 600 m/s, laser power of 130 W, hatch distance of 80 µm, layer thickness of 30 µm, and energy density of 90.67 J/mm³ on DMLS. The results suggest that the functional prototypes (prepared with recycled powders) have a peak load of 14,050 N, ultimate stress of 585.5 MPa, and break distance was noticed as 5.63 mm. The 26.8% reduction in tensile strength of the fabricated parts was noticed from the virgin 17-4 PH SS. However, the blended metallic powder may be used for printing scaffolds/implants (having mechanical properties close to the natural bone) as an alternative solution.