This grant provides funding to explore and elucidate fundamental bonding mechanisms that occur between particles in kinetic consolidation processes, such as ultrasonic fabrication and cold spray deposition. The developed models will describe physical aspects of particle interaction affecting structure, properties and performance of consolidated materials. In addition, specific bonding criteria will be pursued in a range of materials systems to improve current techniques as well as critical design tools for usage of new materials. Computational simulations of particle impact during cold spray will identify distributions of stress and temperature. These data will be correlated with high-resolution metallographic observations on particles experimentally impacted under identical conditions. Further, parallel microscopic studies on specimens produced via ultrasonic consolidation will provide data to explore similarities between the two techniques as well as test modeling predictions with a more controllable particle stress state. Mechanical characterization will be explored on all specimens to develop interfacial structure-property relationships and explore deformation and failure criteria in these materials.
If successful, the results of this research will lead to improvements in the design of kinetic consolidation processes for currently-used materials such as aluminum, magnesium and copper alloys as well as establish process conditions to enable new materials systems to be produced. The primary goal of this work is to determine how contacting particles develop strong bonds when subjected to supersonic impact or ultrasonic vibratory conditions. Results may then guide industrial practice in input parameters, tool design, material selection, and pre-/post-processing techniques. In turn, this could improve fabrication efficiency and mechanical behavior, or accelerate insertion of these materials into new applications. The proposed work will also expand understanding of metallurgical thermodynamics and kinetics under high plastic strain rates.