TY - JOUR
T1 - Experimental validation of negative stacking fault energies in metastable face-centered cubic materials
AU - Werner, Konstantin V.
AU - Niessen, Frank
AU - Villa, Matteo
AU - Somers, Marcel A. J.
PY - 2021
Y1 - 2021
N2 - Stacking fault energy (SFE) is considered an important parameter to predict the prevalent plastic deformation mechanism in face-centered cubic (fcc) alloys. Experimental methods for determining SFE presuppose that SFE is positive. Density functional theory (DFT) is a promising tool to predict alloy compositions with low SFEs and desirable mechanical properties. For metastable fcc alloys, DFT predicts negative SFE values, which cannot be validated by the existing experimental procedures. In this contribution, it is demonstrated that experimental procedures to assess SFE values only provide an apparent value that needs correction. The suggested correction relies on the critical resolved shear stress for twinning, which is grain size-dependent, just like the apparent SFE. The correction provides SFE values that are independent of grain size. Accordingly, negative SFEs predicted by DFT can be experimentally validated.
AB - Stacking fault energy (SFE) is considered an important parameter to predict the prevalent plastic deformation mechanism in face-centered cubic (fcc) alloys. Experimental methods for determining SFE presuppose that SFE is positive. Density functional theory (DFT) is a promising tool to predict alloy compositions with low SFEs and desirable mechanical properties. For metastable fcc alloys, DFT predicts negative SFE values, which cannot be validated by the existing experimental procedures. In this contribution, it is demonstrated that experimental procedures to assess SFE values only provide an apparent value that needs correction. The suggested correction relies on the critical resolved shear stress for twinning, which is grain size-dependent, just like the apparent SFE. The correction provides SFE values that are independent of grain size. Accordingly, negative SFEs predicted by DFT can be experimentally validated.
U2 - 10.1063/5.0063761
DO - 10.1063/5.0063761
M3 - Journal article
SN - 0003-6951
VL - 119
JO - Applied Physics Letters
JF - Applied Physics Letters
M1 - 141902
ER -