Master'sOpen AccessEN
TiTaNbHfZr high entropy alloy as a biomedical coating on metallic implant materials
This study investigates TiTaHfNbZr and Ti1.5Ta0.5Hf0.5Nb0.5Zr high entropy alloy depositions on NiTi shape memory alloy and 316L stainless steel substrates. Nanoindentation, XRD, AFM, SEM, EDS, XPS and ICP-MS analyses were conducted to interpret mechanical properties, microstructures, bioactivities and biocompatibilities of coatings. Study proved that RF Magnetron Sputtering of HEA coatings improve mechanical performance of NiTi SMA and 316L SS substrates, providing better wear resistance. Coatings are much more prosperous to form hydroxyapatite particles than 316L stainless steels, which is an indicator of improved bioactivity. A flawless HEA coating followed by thermal oxidation definitely blocks ion release to surrounding tissue. However, any discontinuities due to erroneously coated films pose a risk of more ion release than uncoated 316L SS. HEA coatings also effective on preventing Ni ion release from NiTi SMAs. This work states that amorphous TiTaHfNbZr and Ti1.5Ta0.5Hf0.5Nb0.5Zr high entropy coating is a promising surface modification for metallic implants.
