Effect of Si and B on the Electrochemical Behavior of FeCoNiCr-Based High-Entropy Amorphous Alloys

Abstract

The ability to produce high-entropy alloys with an amorphous structure, so-called high-entropy metallic glasses (HEMGs), offers the possibility to produce new compositions with good mechanical properties and resistance to corrosion. In this study, corrosion behavior was studied in two HEMGs, FeCoNiCrB and FeCoNiCr(BSi). In both cases, the total amount of metalloid atoms was kept constant at 20 at.%. The electrochemical behavior of these alloys was studied by means of linear polarization resistance (LPR) measurements and electrochemical impedance spectroscopy in a 3 wt.% NaCl solution. The effect of corrosion was characterized by using X-ray photoelectron spectroscopy (XPS) and the surface morphology was checked using a scanning electron microscope (SEM). The results show that samples with B but without Si exhibit better corrosion resistance due to its chemical homogeneity and lack of structural heterogeneity.

Compositionally Complex Alloys: Some Insights from Photoemission Spectroscopy

“…However, the corresponding values of the Curie temperature, T C and the average magnetic moment m depend on the calculation method used (e.g., T C = 23 K and m = 0.39 µ B was calculated in [ 38 ]). These same—but experimentally determined—parameters also show a large scatter, which is most likely a consequence of the difficulties in achieving a homogeneous distribution of the constituents in the solid solution due to their different bonding tendencies to other constituents [ 39 , 40 , 41 , 42 , 43 ]. The corresponding scatter in the values of the magnetic parameters of the Cantor alloy, obtained by different calculations, is probably associated with the intricacies of these calculations [ 13 ].…”

“…The materials, methods of preparation, processing and characterization of the samples and a technique of performing ultraviolet photoemission spectroscopy (UPS) measurements used for quinary Ti-Zr-Nb-Cu-Ni metallic glasses (MG) and the Cantor type of quinary Cr-Mn-Fe-Co-Ni, 3d transition metal alloys with the face-centered cubic structure have been described in some detail elsewhere [ 11 , 22 , 23 , 25 , 26 , 27 , 28 , 31 , 39 , 40 , 41 , 42 , 43 ]. For completeness, we briefly revisit some of the issues in those materials and then present a comprehensive PES study of the senary Al-Ti-Zr-Pd-Cu-Ni alloy.…”

“…The annealed samples (still in a He atmosphere) were quickly cooled to room temperature. All annealed samples underwent a thorough characterization, which included XRD and SEM/EDS studies, as well as differential scanning calorimetry [ 28 , 31 , 39 , 40 , 41 , 42 , 43 ]. XRDs of all studied alloys exhibited four peaks corresponding to the single face-centered cubic (FCC) phase.…”

“…It is therefore surprising that PES studies of CCAs were virtually nonexistent until about five years ago [ 22 ]. Actually, there was limited use of X-ray photoelectron spectroscopy of the core levels in recent studies of the surface oxidation and corrosion resistance of some CCAs [ 39 , 40 ]. However, these studies did not report the spectra of VBs of studied alloys [ 39 , 40 ], hence they cannot be used to explain other properties of these alloys.…”

“…Actually, there was limited use of X-ray photoelectron spectroscopy of the core levels in recent studies of the surface oxidation and corrosion resistance of some CCAs [ 39 , 40 ]. However, these studies did not report the spectra of VBs of studied alloys [ 39 , 40 ], hence they cannot be used to explain other properties of these alloys. In our previous studies, we used PES of early (TE)–late (TL) transition metal types of a-CCAs to show the influence of particular TL = Co, Ni or Cu on their ES and related properties (such as mechanical, magnetic and superconducting properties) [ 11 , 22 , 25 , 26 , 28 , 29 ].…”