Effect of Lattice Design and Process Parameters on Dimensional and Mechanical Properties of Binder Jet Additively Manufactured Stainless Steel 316 for Bone Scaffolds

Abstract

Scaffolds are 3D biocompatible structures that mimic the extracellular matrix properties (mechanical support, cellular activity and protein production) of bones and provide place for cell attachment and bone tissue formation. Their performance depends on chemistry, pore size, pore volume and mechanical strength. Open and interconnected pores allow nutrients and molecules to transport to inner parts of scaffold. Recently, additive manufacturing (AM) has been used as a means to produce these scaffolds. However, there is a need to study the various lattice designs and process parameters of these AM processes to produce the required scaffolds. In this study, the relationship between different lattice designs of additively manufactured scaffolds and their mechanical properties was studied. Four lattice geometries were fabricated with binder jet AM process with Stainless Steel 316 (SS316) as material. We also studied effect of process parameters such as sintering time and sintering temperature on dimensional accuracy and mechanical properties of these geometries. The results showed that the samples with circular geometry have superior mechanical properties compared to others. Trends were obtained on the influence of different lattice designs on compressive strength of the material.