Interfacial engineering for enhanced mechanical performance: High-entropy alloy/graphene nanocomposites
Yeran Shi, Wenting Ye, Dongpeng Hua, Qing Zhou, Zhuobin Huang, Yuxin Liu, Shuo Li, Ting Guo, Yongnan Chen, Stefan J. Eder, Haifeng Wang
Abstract
In pursuit of high-performance materials, the synergistic combination of high-entropy alloys (HEAs) and graphene (Gr) has emerged as a promising approach. Here, we report a groundbreaking study on CoCrFeMnNi/Gr nanocomposites that highlights their exceptional mechanical properties. Leveraging on molecular dynamics simulations, we reveal the underlying mechanisms that govern the tensile behavior of these nanocomposites. Notably, we demonstrate that the introduction of graphene has a profound impact on the nucleation and propagation of dislocations in HEA. The interface between the HEA and graphene serves as a remarkable source for dislocations, leading to a transformative alteration of the dislocation behavior. Moreover, the high stresses accumulated at the interface drive graphene to undergo out-of-plane deformation, accommodating the plasticity of the HEA. We establish that the mechanical properties of these nanocomposites exhibit an intriguing dependence on the tensile direction and the thickness of HEA, which can be accurately described by a modified Hall-Petch relationship. Our findings provide crucial insights into the role of graphene in strengthening CoCrFeMnNi HEA/Gr composites, paving the way for the design of advanced materials with unprecedented strength and ductility. The extraordinary mechanical performance of HEA/Gr nanocomposites unravels a new frontier in materials science, with wide-ranging implications for a broad spectrum of applications, from aerospace to automotive and beyond.