Synthesis of Refractory High-Entropy Alloy WTaMoNbV by Powder Bed Fusion Process Using Mixed Elemental Alloying...

The growing interest in refractory high-entropy alloys (HEAs) in the last decade is mainly due to their thermal stability, outstanding mechanical properties, and excellent corrosion resistance. However, currently HEAs are still not considered for use as common structural materials due to their inherent drawbacks in terms of processing and machining operations. The recent progress witnessed in additive manufacturing (AM) technologies has raised the option of producing complex components made of HEAs with minimal machining processes. So far, this could be achieved by using pre-alloyed powders of HEAs that were mainly produced by a conventional arc melting furnace (AMF) in the form of small compounds that were transformed into powder via a gas atomization process. To significantly reduce the production cost, the present study aims to analyze the ability to synthesize HEA WTaMoNbV via a laser powder bed fusion (LPBF) process using mixed elemental alloying powder as the raw material. For comparison, a counterpart alloy with the same chemical composition was analyzed and produced by an AMF process. The microstructures of the tested alloys were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses. The physical properties were evaluated in terms of density and mechanical strength, while the electrochemical behavior was assessed by potentiodynamic polarization analysis. The results disclosed similarities in microstructure, physical properties and electrochemical behavior between HEA WTaMoNbV manufactured by the proposed LPBF process and its counterpart alloy produced by an AMF process.