Liu Yu, Zheng Guangping
Research Institute of Light Alloy, Central South University, Changsha 410083, China.
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Nanomaterials (Basel). 2022 Jun 23;12(13):2157. doi: 10.3390/nano12132157.
The present work reports the interfacial behaviors and mechanical properties of AlCoCrFeNi high-entropy alloy (HEA) reinforced aluminum matrix composites (AMCs) based on first-principles calculations. It is found the stability of HEA-reinforced AMCs is strongly dependent on the local chemical compositions in the interfacial regions, i.e., those regions containing more Ni atoms (>25%) or fewer Al atoms (<20%) render more stable interfaces in the HEA-reinforced AMCs. It is calculated that the interfacial energy of Al(001)/Al20Co19Cr19Fe19Ni19(001) interfaces varies from −0.242 eV/Å2 to −0.192 eV/Å2, suggesting that the formation of interfaces at (100) atomic plane is energetically favorable. For those constituent alloy elements presented at the interfaces, Ni could stabilize the interface whereas Al tends to deteriorate the stability of interface. It is determined that although the HEA-reinforced AMCs have less yield strength compared to aluminum, their Young’s modulus is enhanced from 69 GPa for pure Al to 134 GPa. Meanwhile, the meaningful plasticity under tension could also be improved, which are related to the chemical compositions at the interfaces. The results presented in this work could facilitate the designs of compositions and interfacial behaviors of HEA-reinforced AMCs for structural applications.
本工作基于第一性原理计算，报道了AlCoCrFeNi高熵合金（HEA）增强铝基复合材料（AMC）的界面行为和力学性能。研究发现，HEA增强AMC的稳定性强烈依赖于界面区域的局部化学成分，即那些含有更多Ni原子（>25%）或更少Al原子（<20%）的区域，在HEA增强AMC中呈现出更稳定的界面。计算得出Al(001)/Al20Co19Cr19Fe19Ni19(001)界面的界面能在−0.242 eV/Å2至−0.192 eV/Å2之间变化，这表明在（100）原子平面处形成界面在能量上是有利的。对于出现在界面处的那些组成合金元素，Ni可以稳定界面，而Al则倾向于降低界面的稳定性。研究确定，尽管与铝相比，HEA增强AMC的屈服强度较低，但其杨氏模量从纯铝的69 GPa提高到了134 GPa。同时，拉伸下有意义的塑性也可以得到改善，这与界面处的化学成分有关。本工作中呈现的结果有助于设计用于结构应用的HEA增强AMC的成分和界面行为。
