Investigation of a Template‐Based Process Chain for Investment Casting of Open‐Cell Metal Foams.

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]