Weizhong Han

The Influence of Rolling Schedule on the Dynamic Properties of Accumulatively Roll Bonded Nano-Layered Cu-Nb

Cu-Nb nanolayered material was produced through an accumulative roll bonding (ARB) technique. Using this technique, two different rolling schedules were employed to produce a normal and transverse rolled material. This resulted in specimens with differing microstructures within the 135nm thick nanolayers and interface structures between the layers. The dynamic response of these bulk Cu-Nb nanocomposites was then investigated under planar shock loading. It was observed in dynamically fractured specimens that the characteristics of ductile failure features formed on the fracture surface after dynamic loading were dependent upon the processing route of the nanocomposite. Specifically, grain shape differences due to dissimilar rolling passes are linked with differences in the failure response, particularly kinetics of fracture. In addition, incipient failure immediately below the primary fracture surface was also observed. Numerous nanovoids were nucleated and aligned linearly in the middle of Cu layers within the shocked Cu-Nb nanocomposites. These observations indicate relative stability of Cu-Nb interfaces produced by the ARB methods utilized in this study under dynamic loading conditions.