Additive manufacturing of cellular cores for overcasting technology

Hybrid aluminum castings with overcasted porous aluminum cores with lower relative density are proposed in order to achieve improved mechanical properties. Porous aluminum cores can be fabricated using several additive manufacturing technologies. Preliminary tensile strength testing of PLA specimens has been conducted to comparatively analyze the influence of infill patterns. Kelvin and Gyroid structures at variable cell dimensions have been chosen for comparison. The results suggest small differences between Gyroid variants and lower elongation when higher relative density of Kelvin structure is used. There is insufficient data and knowledge regarding the process of green part sintering fabricated with the use of highly filled aluminum-polylactic acid filament. Three experimental sintering regimes have been proposed, while unconventional “blast” sintering yielded the most promising results.