**Atomistic calculations of the generalized stacking fault energies in two
refractory multi-principal element alloys**

SZ Xu and E Hwang and WR Jian and YQ Su and IJ Beyerlein, INTERMETALLICS, 124, 106844 (2020).

DOI: 10.1016/j.intermet.2020.106844

In this work, we utilize atomistic simulations to calculate the
generalized stacking fault energies (GSFEs), which are related to the
dislocation glide process, on four types of slip planes -*101*, *112*,
*123*, and *134* - in two refractory multi-principal element alloys
(MPEAs): MoNbTi and NbTiZr. To serve as a reference material for MoNbTi,
we develop, validate, and employ an A-atom interatomic potential, which
is expected to represent the response of the nominal random solution.
Our calculations show that, owing to the variation in local chemical
composition within small finite nanometer sized planes, (i) the peak
GSFE values vary significantly among parallel planes; (ii) within the
same specific *110* plane, substantial differences in the GSFE curves
along the two non-parallel (111) directions are observed; (iii) the
*101* GSFE curves develop an asymmetry, such that the peak energy is not
achieved at half the lattice periodicity length, (iv) the GSFE value
after a shift equaling the lattice periodicity length is not recovered;
and (v) on average, the peak GSFE values are close to the volume
fraction average of the peak GSFEs of their constituents.

Return to Publications page