Nanoindentation behavior of high entropy alloys with transformation-induced plasticity
Nanoindentation behavior of high entropy alloys with transformation-induced plasticity
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DOI：
10.1038/s41598-019-43174-x
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发表时间：
2019-04
影响因子：
4.6
通讯作者：
S. Sinha;R. Mirshams;Tianhao Wang;S. Nene;M. Frank;K. Liu;R. Mishra
中科院分区：
文献类型：
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作者：
S. Sinha;R. Mirshams;Tianhao Wang;S. Nene;M. Frank;K. Liu;R. Mishra
对三种亚稳双相高熵合金进行了纳米压痕实验，获得了它们固有的弹塑性变形响应。铸态条件下硬度和弹性模量的优异组合证实，与文献中报道的其他HEAs相比，它们固有的更高强度可归因于合金化学诱导的相稳定性。此外，在Fe-Mn-Co-Cr-Si-Cu HEA中，通过退火铸态材料获得8.28GPa的硬度与221.8GPa的模量组合，这是迄今为止在HEA中从纳米压痕获得的最佳硬度-模量组合。另一方面，虽然Fe-Mn-Co-Cr-Si HEA显示出比Fe-Mn-Co-Cr-Si-Al和Fe-Mn-Co-Cr-Si-Cu HEA更低的硬度和模量，但是前一合金表现出最高的应变速率敏感性，如从在五种不同应变速率下进行的测试所确定的。这三种合金也有微妙的差异，在初期的塑性和弹塑性行为，同时保持类似的硬度水平;和纳米压痕响应显示微观结构的依赖性，在摩擦搅拌处理，退火和拉伸变形试样。因此，该研究强调，虽然通过设计一类具有相似成分的HEAs实现了更高的强度，但可以调整任何单独的合金以获得增强的性能。
Nanoindentation of three metastable dual-phase high entropy alloys (HEAs) was performed to obtain their inherent elastoplastic deformation responses. Excellent combination of hardness and elastic modulus in as-cast condition confirmed that, their inherently higher strength compared to other HEAs reported in literature, can be attributed to alloy chemistry induced phase stability. Further, hardness of 8.28 GPa combined with modulus of 221.8 GPa was obtained in Fe-Mn-Co-Cr-Si-Cu HEA by annealing the as-cast material, which is the best hardness-modulus combination obtained to date in HEAs from nanoindentation. On the other hand, although Fe-Mn-Co-Cr-Si HEA showed lower hardness and modulus than Fe-Mn-Co-Cr-Si-Al and Fe-Mn-Co-Cr-Si-Cu HEAs, the former alloy exhibited the highest strain rate sensitivity, as determined from tests performed at five different strain rates. The three alloys also had subtle differences in incipient plasticity and elastoplastic behavior, while retaining similar levels of hardness; and nanoindentation response showed microstructural dependence in friction stir processed, annealed and tensile-deformed specimens. Thus, the study highlighted that while higher strength was achieved by designing a class of HEAs with similar composition, any of the individual alloys can be tuned to obtain enhanced properties.