CoCrFeNiTi-based high-entropy alloy with superior tensile strength and corrosion resistance achieved by a combination of additive manufacturing using selective electron beam melting and solution treatment

We succeeded in fabricating a Co1.5CrFeNi1.5Ti0.5Mo0.1 high entropy alloy with superior tensile strength and corrosion resistance by a combination of additive manufacturing using selective electron beam melting (SEBM) and solution treatment (ST). The SEBM specimens exhibited superior tensile properties to those of the corresponding casting specimen. Furthermore, the tensile properties and corrosion properties of the SEBM specimens markedly improved by ST. These notable improvements are ascribed to homogeneous precipitation of very fine particulate ordering-phase particles whose diameters are several tens of nanometers with Ni and Ti concentrations. The solution-treated SEBM specimens also exhibited both high strength and high pitting potential, which in combination are superior to the conventional alloys used in severe corrosion environments.