Processing of Fully-Dense Nanocomposites through Novel Design

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Combustion Synthesis is a manufacturing process that utilizes the chemical energy produced from a reaction between powders during heating. Such internally produced chemical energy can avoid the use of an energy-intensive heating furnace, thus reducing energy consumption during manufacturing. Combustion Synthesis has been used to form many advanced materials including ceramics, intermetallics and composites. So far, this advantageous process of combustion synthesis has generally not been capable of producing pore-free high-strength composites and nanocomposites, except by pressing the materials during manufacturing, and/or using an additional manufacturing step to fully form the material. These are extra energy-intensive and costly steps. This award supports fundamental research to design powders and powder compacts which can form strong pore-free composites and stronger pore-free nanocomposites in only one rapid reaction step, thus eliminating the need for any extra costly and energy-intensive manufacturing steps. The benefits to society will be significant, as there are many materials that can be produced using this process, and they have applications in the aerospace, automotive, biomedical and energy industries. The research project involves the participation of underrepresented and economically disadvantaged students in the research and educational activities, thus engineering education will also be positively impacted.  This research tackles the long-standing Combustion Synthesis problems of residual porosity and inhomogeneity from a new fundamental scientific standpoint. Specifically, the influence of powder and powder compact multi-scale design on the densification and homogenization mechanisms in combustion synthesis will be investigated. A fundamental understanding of the effects of defect concentrations on the rapid synthesis and homogenization of nanocomposites with or without external field will be established for materials that generate a liquid phase during the reaction. The research will fulfill a previously thought to be impossible task of producing full or near-full density homogeneous composites and nanocomposites via combustion synthesis without the application of external pressure or post processing heat treatments. Through in-depth characterization and mechanical properties investigations, the research will also establish the processing-microstructure-properties relations for these new materials.