This Small Business Innovation Research (SBIR) Phase I will develop a new class of nano-engineered multilayers for reactive joining of materials that enables one to control the stability and ignition energy of the corresponding reactive foils. Two general approaches will be explored in this project. The first approach is based on vapor depositing a periodic quad-layer structure, in which two nanoscale layers, alternating between elements with high heats of mixing (Al and Ni), are separated by thinner, barrier layers comprised of a relatively inert material (Cu) that interacts weakly with the other two. Control over foil stability, ignition requirements and reaction properties can then be achieved by varying the nanoscale thickness (0.5nm to 5.0nm) of the inert (Cu) barrier layers. The second approach is based on the development of composite structures, which combine nanolayered reactive foils (50-150 micron thick) with micron scale braze and solder layers. In this approach, one takes advantage of the thermal mass of the braze and solder layers in order to enhance the stability of the reactive foil. In the project, the team will (1) demonstrate the feasibility of this new class of nano-engineered multilayers, (2) characterize their stability and ignition requirements, and (3) develop and validate predictive computational models that complement experimental observations and amplify their scope. Commercially, successful development of these novel nanostructed materials will lead to significant improvement in reactive joining technology. Letters of support from potential customers and suppliers demonstrate interest in the development of stable reactive multilayer foils and their use in joining applications
