Comparative Study of (Fe,Nb)MoTaTiZr High Entropy Alloys in Ringer Grifols Solution

Abstract

High-entropy alloys (HEAs) are a family of materials that, because of their particular characteristics and possible uses in a variety of industries, have garnered a lot of interest recently. One such promising HEA is the MoNbTaTiZr high-entropy alloy, which displays excellent corrosion resistance and biocompatibility alongside good mechanical properties. Another promising HEA that has attracted researchers for its potential applications in various fields is FeMoTaTiZr. Exchanging one of the elements may result in important variation of properties of a material. This work studies two different samples of high-entropy alloys, MoNbTaTiZr (named NbHEA) and FeMoTaTiZr (named FeHEA), both generated in a laboratory context using electric-arc remelting technology, keeping similar atomic percentage of the elements in both alloys. Optical microscopy and scanning electron microscopy techniques were used to characterize the microstructure of the alloys. Replacing Nb for Fe affects the distribution proportion of the other four elements, since Fe has a higher tendency than Nb to form part of the inter-dendrite region. An evaluation of the properties related to the corrosion process was accomplished using the polarization method along with electrochemical impedance spectroscopy (EIS), performed under a simulated biological environment. As a result, FeHEA showed a higher corrosion rate in simulated body fluid than NbHEA.