Predicting single phase CrMoWX high entropy alloys from empirical relations in combination with first-principles calculations

- The ten empirical criterial are used to predict the novel single-phase HEAs.
- The intrinsic ductility is studied via the ab initio alloy method.
- The formation enthalpy is calculated from the high-throughput binary alloy data.

We use the Hume-Rothery rules and abinitio mixing enthalpies to design novel high entropy alloys composed of late 3d metal (Mn, Fe, Co, Ni, Cu) and CrMoW. Results predict that CrMoW, CrMoWMn, CrMoWCo and CrMoWNi adopt single body-centered cubic (bcc) crystal structure. The ab initio calculations of elastic moduli and ideal strengths indicate that the bcc phase is more stable thermodynamically than the face-centered cubic (fcc) crystal structure for CrMoW, CrMoWMn, CrMoWNi HEAs, but the late 3d elements decreases the mechanical stability of the bcc phase. In particular Ni addition increases the intrinsic ductility and decreases the intrinsic strength of CrMoW alloy.

Theoretical Young's modulus plotted in plane (110) as a function of direction (left), including the three main cubic directions, and characteristic surfaces of the Young's modulus (right) for CrMoW, CrMoWMn, CrMoWNi and CrMoWNiFe HEAs.227