This paper reports a dramatic increase in the grain boundary strengthening or Hall-Petch coefficient, K, by systematically investigating the effect of Al addition on tensile yield strength in CoFeNi and CoCrFeNi high entropy alloys (HEAs) or complex concentrated alloys (CCAs). Additionally, detailed atom probe tomography (APT) revealed a high number density of Ni-Al rich nano-clusters in the Al_0.3CoFeNi and Al_0.3CoCrFeNi HEAs/CCAs, which can be rationalized based on the strong chemical ordering tendency between these elements. Consequently, the huge increase in K value can be attributed to the additional stress required for overcoming coherency strain fields arising from these nano-clusters.

通过系统地研究Al的添加对CoFeNi和CoCrFeNi高熵合金（HEAs）或复杂浓缩合金（CCA）中的拉伸屈服强度的影响，本文报道了晶界强化或霍尔-普奇系数K的急剧增加。此外，详细的原子探针层析成像（APT）显示Al _0.3 CoFeNi和Al _0.3 CoCrFeNi HEA / CCA中具有大量的富Ni-Al纳米簇，这可以根据这些元素之间的强烈化学有序化趋势进行合理化。因此，K值的巨大增加可归因于克服由这些纳米团簇产生的相干应变场所需的额外应力。