Mechanical behavior of three-dimensional pyramidal aluminum lattice materials

Al based pyramidal lattice truss materials have been fabricated through 3-D printing and molten metal infiltration technology. It is shown that the designable structures with thin struts and small cells can be realized by this technology. Similar to usual porous materials, the present Al based lattice materials also exhibited three-stage compressive mechanical behavior, i.e. linear elastic, plateau and densification stages. The mechanical properties of the lattice materials showed obvious dependence on the structure parameters including the inclination angle of strut with the bottom plane, strut length and strut diameter etc, but actually all these dependences can be attributed to varied relative densities of the lattice materials. Moreover, it is found that the deformation mode of the lattice materials was different if the inclination angle was obviously changed. When the inclination angle was relatively small, the deformation uniformly took place in the form of strut buckling, while it occurred in a localized zone followed by the extending of the zone if the inclination angle was large enough.