Mechanical properties and biocompatibility evaluation of TiZrNbTaFe high entropy alloy films deposited using a hybrid HiPIMS and RF sputtering system

Given the well-documented low biocompatibility issues associated with conventional metallic biomaterials, there is an urgent need to develop new biomaterials. Biological high entropy alloys (HEAs), designed with non-toxic elements for biomedical applications, represent a significant advancement in metal biomedical materials due to their tunable mechanical properties and excellent biological safety. This study employed a hybrid system that combined a high power impulse magnetron sputtering (HiPIMS) power with a radio frequency (RF) power to synthesize a series of amorphous TiZrNbTaFe HEA coatings, in which the Ti content was varied by changing the RF power applied to the Ti target. One exemplary TiZrNbTaFe film, deposited with a Ti target RF power of 75 W, was thoroughly examined. This film demonstrated several highly promising attributes as a novel metallic biomaterial, including a dense and fine microstructure, good adhesion quality, superior corrosion resistance, and exceptional biocompatibility both in vitro and in vivo. These findings could provide new insights for innovative biomaterials development and help address long-term implantation and implant failure issues.