Persistence of crystal orientations across sub-micron-scale super-grains in self-organized Cu-W nanocomposites

We use precession electron diffraction to investigate the crystallographic character of copper (Cu)-tungsten (W) nanocomposites fabricated via physical vapor co-deposition at 400 degrees C. We observe sub-micron-scale regions, where apparently disconnected Cu and W grains have near-identical crystallographic orientations. This persistence of grain orientations suggests Cu and W grains within these regions are interconnected in 3-D when they first form and may be considered as intercalated, sub-micron-scale super-grains. Indeed, atom probe tomography provides direct evidence of 3-D interconnectivity of W domains. Our findings shed light on the structure and self-organization mechanisms of nanocomposites formed by spontaneous phase separation of co-deposited metals. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study found that in copper-tungsten nanocomposites, the copper and tungsten grains in sub-micron-scale regions have similar crystal orientations and are interconnected in 3D space. Atom probe tomography provides evidence of the 3D interconnectivity of tungsten domains. These findings shed light on the structure and self-organization mechanisms of nanocomposites formed by spontaneous phase separation of co-deposited metals.