Ni/Al foil-based reactive additive manufacturing with fast rate and high energy-efficiency

Additive manufacturing (AM) provides an effective way to fabricate geometrically tailored structures. Existing metal AM technologies depend on external heat-induced phase transformation or consolidation to fabricate structures, showing limited energy efficiency and low manufacturing rate. Here, we report an energy-efficient and rapid strategy for metal AM by uniting self-sustaining metallic reactions with the AM process. Multilayer reactive nickel (Ni) and aluminum (Al) foils are compressed into a hybrid rod with compact bi-continuous Ni and Al phases as feedstock. A transient heat initiated the automatically propagating exothermic reaction among the reactive components, then synchronized with layer-by-layer deposition, forming 3D dense structures without expensive power equipment. The reactive feedstock structural configurations were found to be critical for controlling the deposition rate and mechanical strength of the printed part. The as-printed structure achieves a flexural strength of 170.1 MPa, which can be further improved by post-treatment. Among all metal AM processes, our method realizes the fastest AM rate of 30.0 kg/h, and the lowest AM energy consumption of 3×10⁻⁴kWh/kg, representing over a three-order-of-magnitude reduction in energy consumption compared to the least energy-consuming current metal AM process. Throughout the entire lifecycle of our approach, it is also energy-efficient and economically viable when compared to traditional AM processes. This technology provides a cost-effective, energy-efficient, rapid AM approach to fabricating mechanically robust metallic structures.