Current non-degradable esophageal stents frequently lead to long-term complications during the management of esophageal stricture, which drives a strong need for the development of novel degradable metallic materials with high strength, appropriate degradability and favorable biocompatibility. In this study, supersaturated Fe- x Zn alloys (x = 0, 1.25, 2.5, 5 and 10 at.%) were prepared via a powder metallurgy route combining mechanical alloying (MA) with subsequent fast hot-pressing sintering (FHP). The results reveal that a 40 h-milling duration is feasible for Fe-Zn alloys to achieve sufficient solid solubility and effective grain refinement. The synergy of solid solution strengthening and grain refinement (from 11.47 ± 3.19 μm in pure Fe to 5.24 ± 0.63 μm in Fe-5Zn alloy) mainly contributes to improved mechanical strength (from 681.9 ± 11.7 MPa for pure Fe to 787.9 ± 15.5 MPa for Fe-5Zn alloy) in Fe- x Zn alloys (x ≤ 5 at.%), while Fe-10Zn alloy shows compromised mechanical strength due to excess precipitation of FHP-induced Fe 3 Zn 10 phase. With increased Zn content up to 5 at.%, the degradability and cytocompatibility of Fe-Zn alloys both increase, with Fe-5Zn alloy exhibiting a corrosion rate (0.130 ± 0.005 mm/year) over threefold higher than pure Fe (0.031 ± 0.004 mm/year) in a 56-day phosphate-buffered saline (PBS) immersion test. As a result, the supersaturated Fe-5Zn alloy with improved strength, enhanced degradability and favorable cytocompatibility is considered as a potential biodegradable metallic material for esophageal stent application. • Supersaturated Fe-Zn alloys were fabricated via a powder metallurgy route. • Fe-Zn alloys show more uniform and accelerated degradation compared to pure Fe. • Fe-5Zn alloy exhibits enhanced mechanical strength, degradation and cytocompatibility.
Huang et al. (Thu,) studied this question.