Deformation of Fe and Ag precipitates in Cu matrix

摘要

The co-deformation of face centered cubic-face centered cubic and face centered cubic-body centered cubic systems were investigated using the cold drawn Cu-6 wt% Fe-4 wt% Ag alloys. Ag and Fe precipitates were introduced in the Cu matrix simultaneously and bonded together. Ag precipitates were successfully refined to nanofibers after heavy cold drawing while the Fe precipitates are hardly deformed. In-situ tensile test was performed in transmission electron microscope to reveal the dynamic interaction between Cu dislocations and Fe precipitates. Cu dislocations bowed out and bypassed the Fe precipitates while some residual segments were pinned at the Cu/Fe interface. Few dislocation pileups were found around the Fe precipitates. The different flow stress and slip system between Fe nanoprecipitates and Cu matrix are main reason for the poor co-deformation capability. The co-deformation of face centered cubic-body centered cubic system should be scale dependent.