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. High Entropy Alloy (HEA) fabricated by a combination of selective electron beam melting (SEBM) and solition treatment (ST) shows superior tensile strength and corrosion resistance to the conventional alloys used in severe corrosion environments. These notable properties are ascribed to homogeneous precipitation of fine particulate ordering-phase particles whose diameters are several tens of nanometers with Ni and Ti concentrations. [Display omitted] •We could fabricate a CoCrFeNiTiMo-based high entropy alloy by selective electron beam melting.•The molds exhibited superior tensile properties to those of the corresponding casting specimen.•The tensile properties and corrosion properties of the molds markedly improved by heat treatment.•These properties of the heat-treated molds are superior to the conventional alloys.