Additively Manufactured Metal Foam Rail Tank Car Structures

Rail tank cars are routinely used to transport hazardous materials. Additionally, their use has increased appeal because pipeline construction increasingly has a political cost. Hazmat transport by rail is insecure, and the materials transported pose serious hazards to populations along railway lines in derailments and/or collisions, including fire and explosion, acute and chronic toxicity to exposed populations, and environmental contamination. Metal foams are low density materials with high specific strength, are good kinetic energy absorbers, and are actively being explored for use in transport and passenger vehicles. Recent advances include development of composite metal foams (CMF), yielding more controlled foam structure than other metal foams and somewhat reduced anisotropy. Despite these advances, CMFs are difficult to manufacture, and foam cell lattice structure is still far from controllable. Additive manufacturing (AM) can produce metal foams of any shape with precise control over foam cell lattice, and nearly unlimited design flexibility in terms of cell size, shape, and distribution of cells, but metal AM is prohibitively expensive for producing metal panels. We will apply an innovative AM technology for metal foam production that is low-cost and immediately scalable, enabling a rapid transition to the hardening and structural augmentation of DOT-111 tank cars.