The invention discloses a high-strength,
corrosion-resistant and medium-entropy
alloy and a preparation method thereof. The component of the medium-entropy
alloy is (CoCrNi)(100-x)Mnx, the
atomic ratio of Co to Cr to Ni is (0.5-1):(0.5-1):(0.5-1), the value range of x is 1at%-10at%, , the
alloy is formed through mixing,
smelting, homogenizing treatment, rolling and heat treatment
machining, the grain size of the alloy ranges from 30 mu m to 200 mu m, the
manganese-rich phase is separated out of the
grain boundary, the tensile strength of the alloy is higher than 1,200 MPa, the
ductility is higher than 10%, the
corrosion potential ranges from negative 0.43 V to negative 0.26 V, and the medium-entropy alloy is applicable to
marine engineering equipment. The preparation process
route of the alloy includes vacuum
smelting, suction
casting, homogenizing annealing, cold rolling and heat treatment. Co, Cr and Ni with the purity being 99% or higher are selected and weighed according to the proportion and are smelted repeatedly in a vacuum
smelting furnace, suction
casting forming is performed after the component is uniform, multi-pass cold rolling is adopted after annealing treatment, a plate which is 1-2 mm thick is obtained, the tensile strength of the plate is higher than 1,200 MPa, the
ductility is higher than 10%, and the
corrosion potential ranges from negative 0.43 V to negative0.26 V.