Effect of amorphicity of HVOF sprayed Fe-based coatings on their corrosion performances and contacting osteoblast behavior

Fe53Cr19Zr7Mo2C18Si coatings with amorphous/nanocrystalline hybrid structures were fabricated by high velocity oxy-fuel spray. Enhanced amorphicity of the coatings, 55.85%, has been achieved by the spray quenching of the starting feedstock with an amorphicity of 36.82%. Further examination of the coating after post-spray crystallization annealing at 750 degrees C was also conducted. Microstructure, microhardness, wear/corrosion resistance and biocompatibility of the coatings were systematically studied. Results show that the nanocrystallization treatment brought about increased microhardness and enhanced anti-wear performances. However, electrochemical and in vitro cell culture testing suggest that the full crystalline structure does not favor the anti-corrosion and biological performances while presence of the amorphous structure enhances corrosion resistance of the coatings and promotes attachment and proliferation of osteoblast cells on their surfaces. The results shed some light on developing amorphous metallic coatings for potential biomedical applications. (C) 2016 Elsevier B.V. All rights reserved