High-entropy alloys have received significant attention because of remarkable structural properties exhibited by certain alloy compositions. However, these properties are strongly correlated to the crystallographic phase transformations that are endured during the synthesis of these alloys. Using molecular dynamics simulations, we examine how the cooling rates exerted on the alloy melt during synthesis impact the crystallization (and glass formation) of equiatomic AlCoCrFeNi high-entropy alloy. An increased cooling rate contributes to severe undercooling of the alloy, reducing the crystallization temperatures and promotes phase transformations. We predict a critical cooling rate of 2.5 × 10¹⁰ K/s beyond which the alloy tends to solidify into an amorphous phase. Our results reveal that higher cooling rates exert severe lattice distortion and significantly enhance the structural properties due to increase in dislocation density and deformation by twinning.

由于某些合金成分表现出显着的结构性能，高熵合金受到了极大的关注。然而，这些特性与在这些合金的合成过程中经受的结晶相变密切相关。使用分子动力学模拟，我们研究了合成过程中施加在合金熔体上的冷却速率如何影响等原子 AlCoCrFeNi 高熵合金的结晶（和玻璃形成）。增加冷却速度有助于合金严重过冷，降低结晶温度并促进相变。我们预测临界冷却速率为 2.5 × 10 ¹⁰K/s 超过该值，合金趋于凝固成非晶相。我们的结果表明，较高的冷却速率会产生严重的晶格畸变，并且由于孪晶引起的位错密度和变形的增加而显着增强了结构性能。