Abstract Scope |
In multi-principal element alloys (MPEAs), the local chemical composition fluctuations lead to spatially varying material properties such as the surplus energy landscape when two slip planes are rigidly shifted against each other. In this work, we investigate the generalized stacking fault energies (GSFE) in equal-molar body-centered cubic (BCC) MoNbTi MPEAs via density functional theory calculations. First, three different simulation cells for a given composition are represented by special quasirandom structures. The lattice parameter and elastic constants are obtained. Then, GSFEs on three slip planes –– {110}, {112}, and {123} –– are calculated by exhausting all possible atomic displacements within the three simulation cells. It is found that the {110} GSFE curves, which are symmetric in pure BCC metals, become asymmetric in MoNbTi MPEAs. For all three slip planes, a large variation in the GSFE values is identified and is related to the local chemical environment. |