Irradiation‐Induced Extremes Create Hierarchical Face‐/Body‐Centered‐Cubic Phases in Nanostructured High Entropy Alloys
Irradiation‐Induced Extremes Create Hierarchical Face‐/Body‐Centered‐Cubic Phases in Nanostructured High Entropy Alloys
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DOI：
10.1002/adma.202002652
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发表时间：
2020-08
影响因子：
29.4
通讯作者：
Li Jiang;Yong-Jie Hu;K. Sun;Pengyuan Xiu;M. Song;Yanwen Zhang;Walker L Boldman;M. Crespillo
中科院分区：
文献类型：
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作者：
Li Jiang;Yong-Jie Hu;K. Sun;Pengyuan Xiu;M. Song;Yanwen Zhang;Walker L Boldman;M. Crespillo
报道了通过离子辐照在纳米晶NiFeCoCrCu高熵合金（HEA）膜中形成纳米级分级双相结构。在高能粒子引起的极端能量沉积和随之而来的热能耗散下，揭示了一种全新的现象，其中原始的单相面心立方（FCC）结构部分转变为体心立方（BCC）结构的交替纳米层。方位关系遵循西山-瓦塞尔-曼关系，即（011）BCC||（1 <$1 <$1）FCC和[100]BCC|| [ 11 <$0] I'm sorry.模拟结果表明，Cr作为体心立方的稳定元素，表现出向层错偏聚的趋势。此外，在每个纳米晶晶粒中的高密度SF和孪晶界有助于加速辐照期间BCC相的成核和生长。通过调节辐照参数，可以实现层压体中FCC和BCC相的期望厚度。这项工作证明了在离子辐照下有吸引力的双相纳米层压结构的可控形成，并为设计HEAs的新衍生物结构提供了策略。
A nanoscale hierarchical dual‐phase structure is reported to form in a nanocrystalline NiFeCoCrCu high‐entropy‐alloy (HEA) film via ion irradiation. Under the extreme energy deposition and consequent thermal energy dissipation induced by energetic particles, a fundamentally new phenomenon is revealed, in which the original single‐phase face‐centered‐cubic (FCC) structure partially transforms into alternating nanometer layers of a body‐centered‐cubic (BCC) structure. The orientation relationship follows the Nishiyama–Wasser‐man relationship, that is, (011)BCC || ( 1¯1¯1)FCC and [100]BCC || [ 11¯0]FCC. Simulation results indicate that Cr, as a BCC stabilizing element, exhibits a tendency to segregate to the stacking faults (SFs). Furthermore, the high densities of SFs and twin boundaries in each nanocrystalline grain serve to accelerate the nucleation and growth of the BCC phase during irradiation. By adjusting the irradiation parameters, desired thicknesses of the FCC and BCC phases in the laminates can be achieved. This work demonstrates the controlled formation of an attractive dual‐phase nanolaminate structure under ion irradiation and provides a strategy for designing new derivate structures of HEAs.