On the miscibility gap in tungsten-based alloys

Abstract

In this work we establish an approach to model miscibility gaps of alloys using statistical physics, lattice dy-namics from first-principles calculations. We carefully calculate the entropy to include all processes introducing disorder to the system, i.e., combining the electronic, phononic, and configuration entropies. Furthermore we present our algorithm for generating Special Quasirandom Structures (SQS). We model the miscibility gap in tungsten -chromium and tungsten -molybdenum systems, obtaining the agreement with the experimental data. Furthermore, we propose an enhancement for the tungsten-chromium W70Cr30 alloy with tantalum and hafnium, leading to the modified stabilization temperatures TS, where the solid solution is miscible.