In situ preparations of bi-continuous interpenetrating porous composites with high energy absorption

In this paper, porous composites with bi-continuous interpenetrating aluminum foam (AF) and lattice structure were prepared via different sequences. The effect of the preparation sequence on the mechanical properties was analyzed. The results showed that the composites prepared by disordered-ordered and ordered-disordered sequences had higher mechanical properties than the sum of their single components. Porous composite prepared by the disordered-ordered sequence had a discontinuous interface while the one prepared by the ordered-disordered sequence presented a continuous bonding interface and a bubble-free layer. The energy absorption of the porous composite structure prepared by the disordered-ordered sequence was enhanced by the factors of 0.89 and 1.12 over the sum of their single components, while the ordered-disordered was enhanced by the factor of 1.9 and 3.81, which was attributed to the metallurgical bonding, 3D mechanical constraints and the fraction of bubble-free layer that formed between the interfaces. The continuous interface contributed the excellent mechanical properties of the composites due to its higher failure strength before detaching. The presence of the bubble-free layer increased the interfacial contact area, which can effectively absorb energy and exhibit significant deformation resistance. The porous composite exhibited excellent comprehensive performance, which provided a new idea for the structurally and functionally integrated design of porous composites.