Mechanical and Degradation Behavior of Zinc-Based Biodegradable Metal Foams

Zinc has gained interest as a biodegradable material due to its adequate degradation behavior under physiological conditions and acceptable biocompatibility. However, during the use of zinc as a degradable orthopedical implant, the mechanical properties are expected to change while the implant needs to maintain its function and mechanical support for 12-24 months with the load gradually transferred from the degrading implant to the healing bone. For such investigation, six different kinds of open-cell zinc foams are fabricated by a modified investment casting method displaying different pore densities and strut thicknesses. Compressive properties and corrosion behavior in simulated body fluids are studied to determine the map of the most relevant parameters that influence the degradation properties. After 4 weeks of immersion in Hank's solution, changes in the slope in the "plateau" region and strain localization are observed. These changes can be explained by supposing microcrack propagation into the depth of the struts due to the progressing corrosion attack. Zinc has the potential to be used as the material of biodegradable orthopedical implants. Zinc foams are prepared with different densities, and compressed as cast and after 4 weeks of immersion in Hank's solution. The changes in deformation behavior are attributed to the corrosion taking place inside the struts on the surfaces of the microcracks which form during corrosion. image (c) 2024 WILEY-VCH GmbH