Computer simulation and experimental study of W-Ta particle separation in a chromium-based alloy

Diffusion transport in phases that can precipitate from a solid solution in the Cr-30 wt.% Ta-10 wt.% W alloy has been studied using computer modeling methods. Analysis of the results indicates the possibility of CrW, TaW, and W particle precipitation within the chromium phase Cr2Ta in the studied alloy, with diffusion within CrW and WTa particles leading to an increase in the degree of order in their structure. Diffusion coefficients of atoms via the vacancy mechanism in phases of equiatomic composition CrW and TaW with random and ordered atomic distribution have been calculated. Using transmission electron microscopy methods, including energy-dispersive X-ray spectroscopy and electron diffraction, confirmation of the predicted possibility of TaW phase particle precipitation from the solid solution, primarily observed at crystal structure defects, has been obtained. The obtained results can be used in the development of new heat-resistant dispersion-strengthened alloys based on BCC refractory metals.