Search

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. [ABSTRACT FROM AUTHOR]

Herein, a holistic investigation of the process chain of polymer foam template manufacturing for the investment casting of open‐cell metal foams and their evaluation in terms of mechanical response under compressive loading is presented. Polymer foam templates are manufactured using sucrose beads as spaceholders with a body‐centred cubic (bcc) stacking and epoxy resin as matrix material. These templates are used in a modified investment casting process to produce commercial pure open‐cell Al foams (AA 1050 A). The materials used for the polymer foam templates are suitable for the template production and the use in investment casting. The structure of the template can be exactly reproduced by investment casting and no byproducts from the pyrolysis step can be detected within the molds or the Al foams. The mechanical properties under compressive loading are comparable with high‐strength Al‐alloy foams with a structure factor of C1 of 0.60. The characteristic plastic deformation is dominated by buckling, showing a local plastic failure of the struts within cell layers. Due to a high node‐to‐strut thickness ratio, neither small defects in the microstructure nor stacking errors of the template impact this deformation behavior. [ABSTRACT FROM AUTHOR]

Copyright of Bányászati és Kohászati Lapok - Kohászat is the property of Hungarian Mining & Metallurgical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)