Keynote: Tailoring Thermal Spray Process and Materials for Needs of the 21st Century
The key challenge to adapt thermal spray process and materials to meet the altering technological needs of the 21st century is the absence of understanding of the role of processing on evolution of nanomaterial reinforcements during spraying, their integration with sprayed splats, and their effect on the mechanical behavior of the deposits. Plasma and cold spray have been employed to manufacture metal and ceramic-based composite deposits reinforced by 3D nanoparticles, 2D layered nanoplatelets, and 1D nanotubes. A range of optical, electron microscopic, nanoindentation, and tensile techniques reveal that specific surface area of the nanoparticles plays a key role in matrix-reinforcement interface chemical bonding. This determines their enhancement in elastic moduli, hardness, and tensile strength with the reinforcements bearing higher loads, arresting crack propagation by bridging, and sheathing of matrices around their surface. Establishment of these process-structure-property correlations harbors the potential to advance large-scale manufacturing of thermal sprayed nano composites.