3D atom probe investigation of nanocomposite wires

Two kinds of high strength nanocomposite wires produced under heavy plastic deformation were investigated using 3D Atom Probe. First, cold drawn pearlitic steel wires were analysed. Partly dissolved cementite lamellae were mapped out in 3D. The surface to volume ratio of cementite lamellae was correlated to their dissolution rate. Considering the increase of the interfacial energy during drawing, a model based on simple thermodynamical arguments was developed to estimate the global dissolution rate of cementite. Cu/Nb nanocomposite wires were also studied. Their nanoscale cross-section microstructure was revealed for the first time. 3D Atom Probe analysis pointed out a slight inter-diffusion of copper and niobium, and steps in copper channels attributed to tracks of moving dislocations in the (111) Cu plane, along the < 110 > direction.