An open cellular lattice structure based on a cubic body diagonal (CBD) topology is fabricated by vacuum-assisted investment casting of Al-33 wt.% Cu eutectic alloy using 3D printed polymer preform with a pore size of a few millimeters. The CBD struts showed lower microhardness ( \(\approx \) 150 HV) compared to the bulk master alloy ( \(\approx \) 191 HV) due to the coarser eutectic resulting from very slow cooling rate (0.04 \(^{\circ }\) C/s) inside the ceramic mold in the vacuum chamber. The metallic lattice is subsequently dealloyed in NaOH producing a hierarchically porous Cu structure with additional porosity at micro and nanoscales. Optimum dealloyed conditions are found to be 1 M NaOH at 60 \(^{\circ }\) C to obtain uniform nanoporous Cu within the Al \(_2\) Cu eutectic lamellae. The morphology of the nanoporous copper ligaments is affected by solution temperature but is less sensitive to its concentration. The depth of dealloying within CBD struts follows a power law scaling with the dealloying duration with an exponent of 0.5. The macroporous, as well as the partially dealloyed hierarchical porous structures exhibit quasi-brittle failure under compression loading with a peak stress of 4 MPa and 1.5 MPa, respectively.
