Sponsor: Office of Naval Research, Department of Defense
Thermal spraying of nanostructured powders prepared by mechanical alloying/milling or other synthesis methods presents a novel approach, due to the reported improvements in physical properties of nanostructured coatings. The objective of the present research is to (1) study the fundamental synergism between thermal spray synthesis, microstructural evolution and mechanical behavior of Ni, Al and Fe based nanostructured materials, (2) develop a mathematical model to predict the momentum and thermal behavior of the micron-sized particles with nanostructured grain structure during the HVOF spraying process, and (3) study the underlying scientific understanding of the factors that contribute to the formation of nanocrystalline structure in the thermal sprayed coatings.
The principal research work conducted includes (1) developing a mathematical model to predict the momentum and thermal behavior of the nanostructured powders during the HVOF spraying and comparison of the calculated results with the temperature profile obtained from the diagnostic measurements, and (2) analysis of the relevant oxidation mechanisms involved during coating formation.