Processing of magnesium foams by weakly corrosive and highly flexible space holder materials

• High-purity magnesium foam was prepared in the study.
• The structure and property of magnesium foam can be regulated.
• The porous magnesium with spherical pores presents nearly isotropic properties.
• Magnesium foams have a great potential in bone implant applications.

High-quality magnesium foams were fabricated by an infiltration technology using tailor-made salt–flour mixture space holders. The pore structures and mechanical properties of space holder particles as well as the resultant foam production with spherical pores were characterized in the present study. The particles after high-temperature sintering dissolved rapidly in water due to their porous structures, guaranteeing the weak corrosion and high-purity of magnesium foams. The spherical pores foams exhibited usual stress–strain behaviors and nearly isotropic properties. The yield strengths of the foams increased with the decrease of sample porosity, and the relative mechanical properties of foams were mostly dependent on their relative densities, which obeyed a power law relation. Moreover, porous magnesium materials with tunable pore structures could be fabricated owing to the flexible forming features of salt–flour mixture, showing great application prospects in bone implant material field.

Stress–strain curves of Mg foam samples machined along different directions (left), change of relative Young’s modulus and yield strength with relative density (right). It can be seen from the above figure that the two foam samples machined from the same ingot along longitudinal and transverse directions have similar porosity and mechanical property, showing nearly isotropic characteristics. The dependence of the relative mechanical properties on their relative densities was observed to obey a power law relation, which would provide the Mg foams with precisely predictable mechanical properties.Figure optionsDownload as PowerPoint slide