Al-Ti interpenetrating phase composites with high strength and specific energy absorption fabricated by additive manufacturing and hot-pressing sintering

In this study, lightweight and high-strength aluminum-titanium (Al-Ti) interpenetrating phase composites (IPCs) were successfully synthesized by integrating additive manufacturing with hot-pressing sintering, which overcomes the well-known issue of immiscible interface. The Ti6Al4V lattice structure acted as reinforcement of AlMgScZr alloy. A diffusion dominated interface was formed between Ti6Al4V and AlMgScZr, and no brittle phase such as Al₃Ti was found. Al-Ti IPCs demonstrate an excellent combination of strength and specific energy absorption. Systematic experiments and simulations reveal two key mechanisms underlying this synergy: (1) the Ti6Al4V skeleton suppresses damage propagation, enhancing structural integrity compared to monolithic AlMgScZr alloys; (2) the AlMgScZr alloy matrix stabilizes the Ti6Al4V lattice against buckling. This work provides new insights into designing lightweight IPCs with superior mechanical performance. (Figure presented.)