High entropy alloy article, product formed of said high entropy alloy article, and fluid machine having said product

An article that is additively manufactured from an alloy, the article comprising:

• matrix phase crystal grains that are equiaxed crystals with an average crystal grain size of 150 μm or less, wherein the equiaxed crystals comprise face-centered cubic crystals;
• and
• ultrafine particles with an average particle size of 100 nm or less, wherein the ultrafine particles are dispersedly precipitated in the matrix phase crystal grains and the ultrafine particles contain a greater concentration of an additional element than in the matrix phase,
• wherein the alloy is a high entropy alloy that has a chemical composition consisting of:
• Co within a range of 20 atomic % or more and 35 atomic % or less;
• Cr within a range of 10 atomic % or more and 25 atomic % or less;
• Fe within a range of 10 atomic % or more and 25 atomic % or less;
• Ni within a range of 15 atomic % or more and 30 atomic % or less;
• Ti within a range of 5 atomic % or more and 15 atomic % or less;
• Mo within a range of more than 0 atomic % and 5 atomic % or less;
• the additional element within a range of more than 0 atomic % and 4 atomic % or less,
• wherein the additional element consists of at least one from among Ta, Nb, Hf, Zr, and Y, and a total content of the additional element and the Mo is within a range of 2 atomic % or more and 6 atomic % or less;
• and
• a balance of inevitable impurities.