The invention discloses a lightweight high-strength multi-principal-element
alloy with ultrahigh
specific strength and a preparation method thereof, and belongs to the technical field of multi-principal-element alloys. The preparation method comprises the following steps: selecting four elements of Ti, V, Zr and Al, weighing according to atomic percent, and obtaining a TiVZrAl
alloy ingot by adopting a
vacuum arc melting method; the TiVZrAl
alloy ingot is subjected to homogenization heat treatment; performing multi-pass cold rolling on the homogenized alloy, and then performing recrystallization annealing; performing multi-pass cold rolling on the annealed alloy; and the cold-rolled alloy is subjected to aging treatment, a nanometer
amplitude modulation decomposition structure is introduced, and the nanometer structure heterogeneity and nanometer chemical heterogeneity enhanced light-weight high-strength multi-principal-element alloy is obtained. According to the invention, through reasonable element screening and proportion regulation and control, a nano amplitude-modulated
decomposition structure is introduced into the alloy to form the nano-structure heterogeneity and nano-chemical heterogeneity reinforced aging-state alloy, so that the problems of insufficient
specific strength and mutual restriction of strength and
plasticity of the existing multi-principal-element alloy are solved.