Physical Vapor Deposition (PVD) nano-multilayered composites of Copper and Niobium have demonstrated extraordinary ability to withstand both mechanical and radiation induced damage nucleation when the layer thicknesses are less than one micron. Although the bi-metallic interfaces are believed to play a role in the enhanced performance, we have yet to demonstrate thorough explanations for these observed performance enhancements. There is a desire to scale the manufacture of this class of materials to commercially viable processes.
For this reason, the accumulated roll bonding process has been developed to manufacture these layered composite materials. During this process, the individual Copper (fcc) and Niobium (bcc) layer thicknesses begin at 1mm and continue until the layer thicknesses become on the order of 10’s of nanometers.
We present a new local single crystal model for the potential influence of the bi-material interface on dislocation motion in the near vicinity of the interface and apply this model to polycrystal multi-layer simulations in an attempt to predict the dominant experimentally observed orientation relationships across the interface. Simple compression and nano-indentation mechanical test results have been used to characterize each of the material model parameter sets. These simulations employ statistically equivalent polycrystal structures as representation of the experimentally characterized individual composite layers. Calculations for the purpose of predicting the evolution of crystallographic texture in these layered composite materials will be presented. Calculations of orientation relationship stability of experimentally observed dominant interface relationships will also be presented and potential hypotheses for these observations will be made. We will also present results of interface orientation relationships across the interface and their evolution. Direct comparison of numerical results to experimental results will be made to the fullest extent possible.