Microstructure and Thermal Conductivity of Fe-Based Amorphous Coatings Prepared by HVOF Thermal Spraying

In this work, gas-atomized FeCr powders were deposited on aluminum substrates by HVOF spraying, forming dispersion strengthened coatings with a dense layered structure and low porosity. SEM, TEM, and XRD analyses show that the coatings primarily consist of amorphous matrix (40%) with precipitated nanocrystals and hard boride phases. A number of coating properties, including microhardness, bonding strength, and thermal conductivity, were measured and are correlated with spraying conditions.