Suppression of shear banding in high-strength Cu/Mo nanocomposites with hierarchical bicontinuous intertwined structures

The microstructures and mechanical behavior of high-temperature co-sputtered Cu/Mo nanocomposites were investigated and compared with Cu/Mo multilayers. The co-sputtered nanocomposites present hierarchical architectures with bicontinuous intertwined Cu/Mo phases, the feature size of which can be tuned from 35 to 3 nm by changing the deposition parameters. After indentation, shear bands were found in the multilayers but not in the hierarchical nanocomposites. In situ nanocompression tests in Transmission electron microscopy showed that the hierarchical nanocomposite containing fine-length-scale intertwined Cu/Mo phases has very high strength. The hierarchical structure is proposed to play an important role in suppressing shear band formation. Impact statement Cu/Mo nanocomposites with novel hierarchical architecture containing bicontinuous intertwined structures were fabricated through co-sputtering. High strength and good deformability were achieved in the nanocomposites through in situ nanomechanical testing.