It is well known that higher energy efficiencies in transportation vehicles can be achieved through component weight reduction. An effective method to reduce vehicle weight is to replace ferrous metals in structural components with novel lighter weight materials that perform well at both ambient and elevated temperatures, such as ceramic-reinforced metal matrix composites. Both small size and uniform distribution of the reinforcement are critical for the mechanical performance of a composite material yet most processes do not produce an effective level for either. This award supports research into a new process for manufacturing nano-ceramic reinforced metal matrix composites using liquid metal processing. This new and energy efficient process will overcome current processing challenges and potentially enable fabrication of composite materials with extraordinary properties. Through direct collaborations with industry, the knowledge, materials, and processing protocols emerging from this work will be readily implemented.
The research introduces a novel method for manufacturing metal matrix nano-ceramic composites using liquid metal processing, where the ceramic reinforcement is directly created in the molten metal using a polymer precursor. Unlike conventional casting methods where the nano-ceramic particles are added and mixed into the metal during processing, the in-situ feature to be studied here offers several potential advantages. These include uniform distributions of nano-scale ceramic particles, well-bonded particle-metal matrix interfaces, broad selection of metal-ceramic systems, and energy and cost savings during processing. The process has been demonstrated to be feasible but the fundamental mechanisms responsible for the material nanostructure and resulting properties are not well established. This research will fill the knowledge gap through systematic experimental studies to understand the mechanisms driving the formation of the nano-ceramic particles, evaluate their behavior and stability at elevated temperatures, and develop effective processing protocols and optimized microstructures. In addition, the work will establish relationships between microstructure and mechanical properties, including fatigue, that are needed to deploy the new metal matrix nano-composites in critical structural applications for the transportation industries.
