Design of non-equiatomic high entropy alloys with heterogeneous lamella structure towards strength-ductility synergy
Design of non-equiatomic high entropy alloys with heterogeneous lamella structure towards strength-ductility synergy
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DOI：
10.1016/j.scriptamat.2018.05.020
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发表时间：
2018-09
影响因子：
6
通讯作者：
Cheng Zhang;Chaoyi Zhu;Tyler J. Harrington;K. Vecchio
中科院分区：
文献类型：
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作者：
Cheng Zhang;Chaoyi Zhu;Tyler J. Harrington;K. Vecchio
通过传统的热机械加工制备了具有异质片层 (HL) 结构的非等原子 FeNiCoAlCrB (NCACB) 高熵合金 (HEA)。在 HL 微观结构中，细晶粒区域是由于 NiAl (B2) 析出物对晶界的齐纳钉扎而抑制晶粒生长而产生的，而粗晶粒区域则源自在没有沉淀物的情况下大变形带内的晶粒生长。通过机械行为和电子背散射衍射验证了异质微结构变形所特有的背应力强化机制，从而实现了几何上必要的位错密度分析。这种机制使 HL-NCACB-HEA 兼具高强度和高延展性。
A non-equiatomic FeNiCoAlCrB (NCACB) high entropy alloy (HEA) with a heterogeneous lamella (HL) structure is fabricated through conventional thermomechanical processing. In the HL microstructure, fine-grain regions result from inhibited grain growth due to Zener pinning of boundaries by NiAl (B2) precipitates, while coarse-grained regions originate from grain growth within large deformation bands in the absence of precipitates. A back-stress strengthening mechanism, unique to deformation of heterogeneous microstructures, is verified through mechanical behavior and electron backscatter diffraction enabled geometrically necessary dislocation density analysis. This mechanism gives rise to the combination of both high strength and high ductility in HL-NCACB-HEA.