Structural, mechanical and biocompatible evaluation of nanocrystalline Ti-Nb-Ta-Cr-Co0.2 HEA for implant applications

High entropy alloys (HEAs) have attracted significant interest in the field of medical applications due to their unique functional properties and remarkable strength. Thus, several Ti-based HEAs have been proposed for bone implants. For the same, the current study proposes a Ti-Nb-Ta-Cr-Co0.2 based HEA, which exhibits better properties compared to commonly used implant materials (such as 316L, cp-Ti, Co-Cr-Mo, and Ti-6Al-4V alloys). The preliminary selection of the atomic % of individual elements for the aforementioned HEA is based on the parametric approach. The proposed combination after mechanical alloying for 50h suggested the coexistence of two BCC phases. This was confirmed by X-ray and electron diffractions. The obtained powder was then consolidated through spark plasma sintering at 1000 °C, resulting into two BCC and one HCP phases. The sintered sample has shown hardness, compressive strength, and Young’s modulus values as ~652 HV, ∼1418MPa, and ~82GPa respectively, which makes it mechanically suitable for the implant application. Additionally, the present HEA after SPS sintering also displayed suitable biocompatibility with MG-63 cells which was evaluated by MTT assay.