Analysis of the corrosion performance of binder jet additive manufactured magnesium alloys for biomedical applications

Binder jet printing (BJP) is a state-of-the-art additive manufacturing technique for producing porous magnesium structures. Porous Mg-Zn-Zr based BJP samples were assessed for corrosion performance in simulated body fluids by electrochemical and hydrogen evolution measurements. The corrosion rates of the BJP specimens were significantly higher than solid controls, even after accounting for their larger surface areas, suggesting that the BJP microstructure is detrimental to corrosion performance. X-ray computed tomography revealed nonuniform corrosion within the porous structure, with corrosion products forming on the pore walls. Impregnating the pores with hydroxyapatite or polymers greatly improved the corrosion resistance of the BJP samples.