Design of BCC refractory multi-principal element alloys with superior mechanical properties

Abstract

The correlations between tensile properties and some common parameters in BCC refractory multi-principal element alloys (RMPEAs) have been systematically investigated. The findings can be used as guidelines for the alloy design. We found that there exists a positive linear correlation between average atomic shear modulus mismatch and yield strength, and more negative enthalpy of mixing is peculiarly prone to brittle fracture in RMPEAs. Meanwhile, some BCC RMPEAs with first-class tensile properties were designed successfully. The analyses of alloys’ toughen mechanism revealed that their high strength, as well as good ductility, is attributed to lattice distortion and dislocation glide respectively. This work provided some effective guidelines for the design of BCC refractory multi-principal element alloys with superior strength-ductility combinations via utilizing several common physical parameters.