Nickel-based superalloys and near-equiatomic high-entropy alloys containing Molybdenum are known for higher temperature strength and corrosion resistance. Yet, complex solid-solution alloys offer a huge design space to tune for optimal properties at slightly reduced entropy. For refractory Mo-W-Ta-Ti-Zr, we showcase KKR electronic-structure methods via the coherent-potential approximation to identify alloys over 5-dimensional design space with improved mechanical properties and necessary global (formation enthalpy) and local (short-range order) stability. Deformation is modeled with classical molecular dynamic simulations, validated from our first-principles data. We predict complex solid-solution alloys of improved stability with greatly enhanced modulus of elasticity (3× at 300 K) over near-equiatomic cases, as validated experimentally, and with higher moduli above 500~K over commercial alloys (2.3× at 2000 K). We also show that optimal complex solid-solution alloys are not described well by classical potentials due to critical electronic effects.
@article{arxiv.1710.06983,
title = {Design of high-strength refractory complex solid-solution alloys},
author = {Prashant Singh and Aayush Sharma and Andrei V. Smirnov and Mouhamad S. Diallo and Pratik K. Ray and Ganesh Balasubramanian and Duane D. Johnson},
journal= {arXiv preprint arXiv:1710.06983},
year = {2018}
}