The Design of Aluminum-Matrix Composites Reinforced with AlCoCrFeNi High-Entropy Alloy Nanoparticles by First-Principles Studies on the Properties of Interfaces

Abstract

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.

Effects of Heat Treatment on the Interface Microstructure and Mechanical Properties of Friction-Stir-Processed AlCoCrFeNi/A356 Composites

“…However, it has been pointed out that Ni was enriched at the edge of the original HEA particle. It has been reported that the electronegativities of Cr, Co, Fe, Ni, and Al atoms are 1.66, 1.88, 1.83, 1.91, and 1.61, respectively, meaning that Ni atoms possessed a better ability to attract electrons from the surrounding Al atoms than those of other metal atoms [ 38 , 39 ]. The charge transfer between Ni and Al atoms was strongest, which promoted Ni to segregate at the layer I/Al matrix interface, thus reducing the total energy of the system.…”

Physical Mechanism of Nanocrystalline Composite Deformation Responsible for Fracture Plastic Nature at Cryogenic Temperatures

“…Currently, there is a need for composite materials with high strength characteristics [ 17 , 18 , 19 ]. In some cases, additional requirements are imposed on the composites, including the ability to maintain performance properties at low temperatures (for example, for Arctic/Antarctic regions, deep space, etc.)…”

“…Therefore, the experimental study of deformation and fracture under uniaxial tension of composite samples at room and cryogenic temperatures becomes important [ 30 ]. In addition, the combination of various types of components in hybrid metal composite materials is known to provide an increase in physicochemical characteristics [ 9 , 10 , 17 , 18 , 19 , 20 ]. This approach is the most promising for the involved class of nanostructured materials.…”