Multi-scale indentation creep behavior in Fe-based amorphous/nanocrystalline coating at room temperature

This work reports first ever investigation on multi-scale room temperature creep behavior of Fe-based amorphous/ nanocrystalline coatings, synthesized via plasma spraying at varying plasma power. Micro- and nano-indentation testing at different loading scales was carried out to reveal the combined effect of microstructural heterogeneities viz. porosity and constituent phases, as well as the individual contribution of amorphous and crystalline phases on the creep behavior of the coatings. Microindentation creep tests revealed higher creep resistance for the coating deposited at elevated power, ascribed to lower porosity and higher degree of crystallinity. Nanoindentation creep tests showed that mixed (amorphous and intermetallic) phase possessed lower creep displacement and retardation spectra compared to fully amorphous one, indicating better creep resistance. The present work provides valuable insight into the effect of microstructural features on the creep deformation behavior of amorphous-nanocrystalline coatings.