Functional characterization of biomechanical loading and biocorrosion resistance properties of novel additively manufactured porous CoCrMo implant: Comparative analysis with gyroid and rhombic dodecahedron

Abstract

Notably, successful clinical outcomes of additively manufactured porous metallic implants require careful consideration of factors such as porosity, pore size, and pore interconnectivity. Applying the SLM technique in Cobalt chrome molybdenum (CoCrMo) alloy fabrication has shown excellent results for prosthetic restorations. However, the corrosion performance of 3D-printed interpenetrating lattices or a combination of minimal surface and strut lattices such as BD.05 (both based on TPMS and struts lattice cells) remains unexplored. This study explores additively manufactured BD.05 structures using CoCrMo as a bulk biomaterial to address the stiffness mismatch, a common cause of stress shielding between implants and bones. Comparative characterization of TPMS-based gyroid and stress lattice-based Rhombic dodecahedron (RH) shows a distinct deformation pattern under quasi-compressive loading. The gyroid exhibits higher yield stress (126.05 MPa), followed by BD-0.5 (25.46 MPa) and RH (9.36 MPa). BD.05 shows an impact strength of 3.17 ± 0.03J/cm2 and a microhardness of 556HV1. Electrochemical measurements demonstrate the inherent corrosion resistance of the fabricated structures. This indicates the appropriate and successful promise of these lightweight interpenetrating-based lattice metamaterial implants in orthopedic applications.