Nano-twin Mediated Plasticity in Carbon-containing FeNiCoCrMn High Entropy Alloys
Nano-twin Mediated Plasticity in Carbon-containing FeNiCoCrMn High Entropy Alloys
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DOI：
10.1016/j.jallcom.2015.05.224
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发表时间：
2015-10
影响因子：
6.2
通讯作者：
Zhenggang Wu;C. Parish;H. Bei
中科院分区：
文献类型：
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作者：
Zhenggang Wu;C. Parish;H. Bei
等原子FeNiCoCrMn合金在低温下表现出良好的强度和塑性，纳米孪晶引起的变形是其主要原因之一。我们使用FeNiCoCrMn合金作为基础合金，通过合金化附加元素，即，间隙碳研究了在77和293 K两种温度下碳对合金显微组织、力学性能和孪晶活动的影响。添加0.5at%C后，高熵合金仍保持完整的单相面心立方（FCC）晶体结构。该材料可以被冷轧和再结晶以产生具有等轴晶粒的显微结构。应变硬化速率和强度均得到提高，同时仍保持高的均匀断裂伸长率（77 K时为70%，293 K时为40%）。含碳高熵合金中形变孪晶的不稳定性可能是导致应变硬化和强度提高的原因。
Equiatomic FeNiCoCrMn alloy has been reported to exhibit promising strength and ductility at cryogenic temperature and deformation mediated by nano-twining appeared to be one of the main reasons. We use the FeNiCoCrMn alloy as a base alloy to seek further improvement of its mechanical properties by alloying additional elements, i.e., interstitial carbon. The effects of carbon on microstructures, mechanical properties and twinning activities were investigated in two different temperatures (77 and 293 K). With addition of 0.5 at% C, the high entropy alloy still remains entirely single phase face-centered cubic (FCC) crystal structure. The materials can be cold rolled and recrystallized to produce a microstructure with equiaxed grains. Both strain hardening rate and strength are enhanced while high uniform elongations to fracture (∼70% at 77 K and ∼40% at 293 K) are still maintained. The increased strain hardening and strength could be caused by the promptness of deformation twinning in C-containing high entropy alloys.