Dual-Nano Composite Design with Grain Boundary Segregation for Enhanced Strength and Plasticity in CoCrNi-CuZr Thin Films
Qiming Zhuang, Dingshan Liang, Jiasi Luo, Kangjie Chu, Kai Yan, Lu Yang, Chengxia Wei, Feilong Jiang, Zongyuan Li, Fuzeng Ren
Abstract
Enhancing both strength and plasticity simultaneously in nanostructured materials remains a significant challenge. While grain refinement is effective in increasing strength, it typically leads to reduced plasticity due to localized strain. In this study, we propose a novel design strategy featuring a dual-nano composite structure with grain boundary segregation to enhance the deformation stability of nanostructured materials. This strategy is demonstrated using a CoCrNi-CuZr multiprincipal element alloy film, which shows a dual-nano composite structure with high-density nanotwins and crystalline–amorphous nanocomposite, along with elemental segregation at the columnar grain boundaries. Our strategy achieves homogeneous plastic deformation in a (CoCrNi) 91 (CuZr) 9 thin film, an 18% increase in strength compared to nanocrystalline CoCrNi, and a 67% increase compared to amorphous CuZr thin films. These results provide valuable insights into designing high-strength, ductile alloys through the engineering of dual-nano composite structures.