The invention belongs to the technical field of
alloy material, and discloses a high-strength high-
toughness ultrafine-grained high-entropy
alloy and a preparation method thereof. The high-strength high-
toughness ultrafine-grained high-entropy
alloy is composed of the following elements according to the atomic percentage: 20%-25% of Ni, 18%-20% of Fe, 18%-22% of Co, 18%-20% of Cr, and 20%-24% of Al; the
microstructure takes a body-centered cubic disordered
solid solution phase rich in Ni and Al elements as a matrix phase, and takes a face-centered cubic disordered
solid solution phase rich in Fe and Cr elements as a reinforcing phase. The preparation method of the alloy comprises the steps: elemental powders with the atomic percentages are subjected to
powder mixing and high-energy ball milling to prepare an amorphous composite
powder, and the amorphous composite
powder is sintered to obtain the high-strength high-
toughness ultrafine-grained high-entropy alloy. The prepared high-entropy alloy has the advantages of
large size and good comprehensive mechanical properties, and can be used in the fields of aeronautics and
astronautics, military industry, electrons, instruments and apparatuses and the like.