Fe and Fe-P Foam for Biodegradable Bone Replacement Material: Morphology, Corrosion Behaviour, and Mechanical Properties

Abstract

Iron and iron-phosphorus open-cell foams were manufactured by a replica method based on a powder metallurgical approach to serve as a temporary biodegradable bone replacement material. Iron foams alloyed with phosphorus were prepared with the aim of enhancing the mechanical properties and manipulating the corrosion rate. Two different types of Fe-P foams containing 0.5 wt.% of P were prepared: Fe-P(I) foams from a phosphated carbonyl iron powder and Fe-P(II) foams from a mixture of carbonyl iron and commercial Fe3P. The microstructure of foams was analyzed using scanning electron microscopy. The mechanical properties and the corrosion behaviour were studied by compression tests and potentiodynamic polarization in Hank’s solution and a physiological saline solution. The results showed that the manufactured foams exhibited an open, interconnected, microstructure similar to that of a cancellous bone. The presence of phosphorus improved the mechanical properties of the foams and decreased the corrosion rate as compared to pure iron foams.

Degradation Performance of Open-Cell Biomaterials from Phosphated Carbonyl Iron Powder with PEG Coating

“…To prevent penetration of open pores, the foams were encased in Parafilm and sequentially weighted in air and water at room temperature. The Archimedes’ principle (DIN ISO3369) was used to determine the density from the following equation [ 28 , 29 ]: where m i , m PA , and m PW are the initial mass (g), mass of the foam encased in Parafilm determined in air (g), and mass of the foam encased in Parafilm determined in water (g), and ρ W and ρ P are the density (g cm −3 ) of water and Parafilm.…”

“…To calculate the total porosity, the weighting of the foam samples was carried out in air and water after vacuum impregnation with benzyl alcohol. The porosity was determined from the following equation [ 29 ]: where m i , m BA , and m BW are the initial mass (g), mass of the foam impregnated with benzyl alcohol determined in air (g), and mass of the foam impregnated with benzyl alcohol determined in water (g), and ρ T is the theoretical density of foam (g·cm −3 ).…”

“…To prevent penetration of open pores, the foams were encased in Parafilm and sequentially weighted in air and water at room temperature. The Archimedes' principle (DIN ISO3369) was used to determine the density from the following equation [28,29]:…”

“…To calculate the total porosity, the weighting of the foam samples was carried out in air and water after vacuum impregnation with benzyl alcohol. The porosity was determined from the following equation [29]:…”

Electrodeposition of Nanocrystalline Fe-P Coatings: Influence of Bath Temperature and Glycine Concentration on Structure, Mechanical and Corrosion Behavior

“…Alloying transition metals with metalloids such as P, B, C, and Si can render amorphous phases. Fe-P coatings have recently raised scientific interest in respect to various advanced applications as temporary biodegradable bone replacement material [7] and alternative Li-ion storage anode [8,9]. Fe-P alloys may also serve as a substitute for widely banned hard chromium.…”