Developing and Testing Sintered and Polymer Infused 3D-Printed Aluminum Reactive Materials

Reactive metals (RM) are composites that can augment the lethality of a warhead via the addition of metal combustion. The possibility of producing a viable 3D-printed aluminum RM is considered in this work. Gas-atomized Al powder was used in a binder jet printer to produce green bodies for testing; the porosity of the as-printed materials is on the order of 47 percent. Sintering of pure Al parts showed little improvement in material density or survivability. Techniques known in the literature to improve Al sintering (addition of tin and use of a reducing atmosphere) were also unsuccessful in giving the parts sufficient strength. Two promising avenues were found. The first is use of gas-atomized aluminum-silicon alloys, which reduces the powder melting point and shows promise for densification of the samples. The second is infusion of the pores with polyurea, which gives the material sufficient strength for use in enhanced blast or incendiary warheads.