TiZr(a=1.5, 0.5, 0.25; b=0.5, 0.25, 0; c=0.5, 0; d=0.5, 0 .75, 1)高熵合金,研 究合金元素含量、热力学参数、显微组织间的关系。结果表明,除了 Al 1.5 Mo 0.5 NbTa 0.5 TiZr 合金由 BCC 相和富 Al-Zr 相组成 Abstract:Al a Mo b Nb c Ta d TiZr (a=1.5, 0.5, 0.25; b=0.5, 0.25, 0; c=0.5, 0; d=0.5, 0.75, 1) high-entropy alloys were prepared by a non-consumable vacuum arc melting. The relations of the content of alloying elements, thermodynamic parameters, microstructure evolution were studied. The results show that other Al a Mo b Nb c Ta d TiZr alloys

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... e composed of single-phase BCC solid solution phase except Al 1.5 Mo 0.5 NbTa 0.5 TiZr alloy composed of BCC phase and Al-Zr rich precipitate. The as-cast Al a Mo b Nb c Ta d TiZr high entropy alloy has a typical dendritic microstructure. The elements of Al, Zr and Ti, and the elements of Mo, Ta and Nb are segregated in the interdendritic and dendritic core regions, respectively. The distribution of elements during solidification is scarcely affected by the variation of alloy composition. However, the precipitation of Al-Zr rich precipitate is more significantly affected by Al than Zr. The inhibition of Al-Zr rich precipitate occurs and a solid solution with coarser dendrites is formed in the Al a Mo b Nb c Ta d TiZr high-entropy alloys with the reduction of a, b, c and d. Al 1.5 Mo 0.5 NbTa 0.5 TiZr alloy shows the highest micorhardness with the value of 650.0HV0.3 due to the precipitation of Al-Zr rich phase, and Al 0.25 NbTa 0.5 TiZr alloy shows the lowest micorhardness with the value of 407.6HV0.3. Key words:AlMoNbTaTiZr refractory high-entropy alloy;as cast;phase formation criterion;microstructure