High-Temperature Deformation Behaviors of the C-Doped and N-Doped High Entropy Alloys
High-Temperature Deformation Behaviors of the C-Doped and N-Doped High Entropy Alloys
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DOI：
10.3390/met11101517
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发表时间：
2021-09
期刊：
影响因子：
2.9
通讯作者：
H. Yi;Yifan Zhang;Ren-Yi Xie;Meng Bi;Daixiu Wei
中科院分区：
文献类型：
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作者：
H. Yi;Yifan Zhang;Ren-Yi Xie;Meng Bi;Daixiu Wei
含有多种主要金属成分的高熵合金引起了人们的广泛关注。了解它们的热变形行为和再结晶机制是调整组织和优化力学性能的前提。在1123-1273K，应变速率为0.1-0.001 S−1的高温热压缩条件下，研究了N掺杂和C掺杂面心立方相HEAs的流动行为和再结晶机制。成功地建立了描述流动行为的本构方程，并用应变补偿多项式函数预测了应力-应变曲线。在低温高应变速率压缩时，非连续动态再结晶和连续动态再结晶同时进行，而在高温低应变速率下，发生在初生晶界的不连续再结晶占优势，显著促进了组织的细化和均匀化。因此，较高的温度和较低的应变速率，再结晶的晶粒呈等轴状，织构很弱，更适合于细化晶粒。颗粒的平均尺寸约为10μm。这一研究为通过热机械加工获得的颗粒优化和力学性能提供了依据。
High entropy alloys (HEAs) containing multi-principal metallic constituents have attracted much attention. A good understanding of their hot-deformation behavior and recrystallization mechanism is the prerequisite for microstructures tuning and for optimizing mechanical performance. Here, the flow behavior and recrystallization mechanism of the N-doped and C-doped face-centered cubic phase HEAs are produced at high temperatures by hot-compression at 1123–1273 K, with strain rates of 0.1–0.001 s−1. Constitutive equations were successfully constructed to reveal flow behavior, and stress-strain curves were predicted using strain compensated polynomial functions. Discontinuous and continuous dynamic recrystallization proceeded concurrently when compressed at a low temperature and high strain rate, whereas discontinuous recrystallization, which occurs at primary grain boundaries, became predominant at a high temperature and low strain rate, significantly contributing to the refinement and homogenization of the grains. For this reason, a relatively high temperature and a low strain rate, in which the recrystallized grains exhibit equiaxed morphology and very weak texture, are more suitable for refining grains. The average size of the grains was approximately 10 μm. This study sheds light on grain optimization and mechanical properties through thermomechanical processing.