Orientation effects on strengthening mechanism of network-structured metallic glass composites and nanoglasses

Network-structured metallic glass composites (NMGCs), including nano-glass (NG), are characterized by micron- or nano-sized glassy grains interconnected through glassy grain boundaries. The mechanical performance of these composites is strongly influenced by the microstructural parameters such as grain boundary width, grain size distribution, and particularly, grain boundary orientation alignment with respect to the loading axis. This study elucidates the orientation effect of grain boundaries on strengthening mechanisms that has not received due attention by far. Our findings reveal that composites with properly aligned grain boundaries exhibit superior strength compared to those with randomly oriented boundaries. This orientation-dependent strengthening originates from two synergistic mechanisms: controlled initiation of shear bands at properly oriented interfaces, and regulated propagation pathways for local shear during plastic deformation. These results provide insights for optimizing the synthesis of metallic glass composites, highlighting the critical role of grain boundary engineering in developing advanced metallic glass systems with enhanced strength and damage tolerance.