Enhancing the bioactivity and ductility of bulk metallic glass by introducing Fe to construct semi-degradable biomaterial

Porous Ti-Zr-Cu-Pd-Sn bulk metallic glass (BMG) produced by Spark Plasma Sintering (SPS) in our previous work demonstrates bone-like mechanical properties, effectively mitigating the issue of stress shielding within the implant. Nevertheless, concerns persist regarding the BMG's brittleness and its lack of bioactivity, both of which pose concealed risks in practical applications. In light of these challenges, a semi-degradable biomaterial, the MG-Fe composites, has been meticulously crafted via SPS in this work. The incorporation of ductile Fe phase in the MG matrix significantly enhances its plasticity. Moreover, the degradation of Fe results in the deposition of Ca-P compounds, imbuing the MG-Fe composites with a degree of bioactivity. Furthermore, by introducing a gradient porous structure, researchers have managed to fine-tune the mechanical properties of the MG-Fe composites. This innovative design imparts plastic and ductile compression deformation behavior to the gradient porous MG-Fe composites, offering a potential solution to the issue of brittle fracture behavior observed in conventional brittle BMGs. In addition, the introduction of the gradient porous structure serves to further accelerate the degradation rate of Fe. This advancement holds the potential to strike a dynamic balance with the growth rate of human bone, further elevating the bioactivity of the MG-Fe composites.