The Effect of Using Ferro-Alloy on the Properties of AlCoFeNiMoTi High-Entropy Alloy Produced by Arc-Melting Method: Design of Low Cost

The cost of high-entropy alloys (HEAs) is one of the most major obstacles to their widespread use. The cost of these alloys with significant amounts of five metals might reach very high levels depending on the type and quantity of metal utilised. Therefore, this study examined the effect of the use of ferro-alloys as part of the charge mixture on the properties of AlCoFeNiMoTi alloy. Ferro-alloys are much less expensive than the pure form of the same metal. To that end, two groups of samples were produced. The AlCoFeNiMoTi alloy was produced using high-purity metals as the metallic charge in the first group of samples. Instead of utilising the pure forms of some expensive metals that make up such alloy, as the metallic charge, lower-cost ferro-alloy forms were employed in the second group of samples. Following the preparation of the appropriate compositions, alloys were produced using the arc-melting method, and the produced alloys were subject to homogenization heat treatment. The obtained samples were characterised by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Then, mechanical and corrosion tests were run. The corrosion resistance of the HEAs was compared with an electrochemical polarisation technique in a 3.5% NaCl electrolyte. It was observed that many intermetallics precipitated through the heat treatment of the samples, and the precipitates negatively affected the mechanical properties of the alloy. Also, in the samples in which ferro-alloy was used instead of pure metal, the mechanical properties were substantially degraded. This is believed to be associated with the presence of inclusions and other residues in ferro-alloys. Graphical Abstract: [Figure not available: see fulltext.]