Effect of parameters extrusion‑based 3D printing with metal‑polymer paste and post‑processing on the structure and mechanical properties of 316L steel
Abstract
The study investigated a promising and commercially attractive method for producing metal parts from a metal-polymer paste. The starting material used was a paste containing 79.55 wt. % filler in the form of spherical powder of 316L steel with a typical particle size distribution for selective laser melting additive manufacturing that was D 50 = 39.9 μm. The work was aimed to study printing parameters and post-processing, including debinding followed by sintering, and their influence on the characteristics of the resulting metal samples. Porosity, shrinkage, relative density, microstructure, and mechanical properties of the samples after sintering in the temperature range of 1285–1320 °C were examined. The content of δ-ferrite was assessed, the grain growth process was investigated, and the evolution of mechanical properties was analyzed. The applied printing and post-processing parameters enabled achieving a relative density of 89 %, which is associated with the relatively low filler content in the initial paste. However, the technology is promising for mechanical applications and for manufacturing small batches of complex-shaped parts that are unprofitable to produce using powder bed fusion and directed energy deposition techniques, as well as for obtaining porous structures used, in particular, in the production of implants.